The user wants a C# WinForms project where they can visually design UI forms - essentially a visual designer/builder application. Let me create a comprehensive WinForms project that allows users to: 1. Create a form 2. Add controls to the form (buttons, labels, textboxes, etc.) 3. Drag controls around 4. Resize controls 5. Edit properties of controls 6. Save/load projects 7. Run/preview the form Let me design this as a complete solution. # C# WinForms Visual Designer Project Here's a complete visual UI designer built with WinForms: ## Project Structure ``` WinFormsDesigner/ ├── WinFormsDesigner.sln ├── WinFormsDesigner/ │ ├── Program.cs │ ├── MainForm.cs │ ├── MainForm.Designer.cs │ ├── DesignerCanvas.cs │ ├── ControlPalette.cs │ ├── PropertyGridPanel.cs │ ├── ProjectManager.cs │ ├── ResizableControl.cs │ ├── ProjectData.cs │ └── WinFormsDesigner.csproj ``` ## 1. Project File ```xml WinExe net8.0-windows true enable enable SystemAware ``` ## 2. Program.cs ```csharp namespace WinFormsDesigner; static class Program { [STAThread] static void Main() { ApplicationConfiguration.Initialize(); Application.Run(new MainForm()); } } ``` ## 3. Project Data Model (for Save/Load) ```csharp using System.Drawing; using System.Windows.Forms; namespace WinFormsDesigner; ///

/// Serializable data for a single control on the canvas ///

public class ControlData { public string ControlType { get; set; } = ""; public string Name { get; set; } = ""; public string Text { get; set; } = ""; public Rectangle Bounds { get; set; } public Color ForeColor { get; set; } = Color.Black; public Color BackColor { get; set; } = Color.Control; public Color BorderColor { get; set; } = Color.Gray; public int FontSize { get; set; } = 9; public bool Enabled { get; set; } = true; public bool Visible { get; set; } = true; public string FontFamily { get; set; } = "Segoe UI"; public string Items { get; set; } = ""; // for ComboBox, ListBox public string Placeholder { get; set; } = ""; // for TextBox public int BorderStyle { get; set; } = 1; public int Padding { get; set; } = 0; public bool Multiline { get; set; } = false; public int AutoSizeIndex { get; set; } = -1; // 0=none,1=width,2=height,3=both public string ImagePath { get; set; } = ""; public bool Checked { get; set; } = false; public int ScrollBars { get; set; } = 2; public string Anchor { get; set; } = "TopLeft"; } ///

/// Serializable data for the entire form/project ///

public class ProjectData { public string ProjectName { get; set; } = "Untitled"; public string FormText { get; set; } = "Form1"; public Color FormBackColor { get; set; } = Color.FromArgb(240, 240, 240); public Size FormSize { get; set; } = new Size(800, 600); public string FormIcon { get; set; } = ""; public List Controls { get; set; } = new(); public int FormBorderStyle { get; set; } = 2; public bool FormMaximizeBox { get; set; } = true; public bool FormMinimizeBox { get; set; } = true; public bool FormStartPosition { get; set; } = false; public bool FormTopMost { get; set; } = false; public string FontFamily { get; set; } = "Segoe UI"; public int FontSize { get; set; } = 9; } ``` ## 4. Design-Time Model (wrapped controls) ```csharp using System.Drawing; using System.Drawing.Drawing2D; using System.Windows.Forms; namespace WinFormsDesigner; ///

/// Represents a control placed on the designer canvas. /// Wraps the real control with drag/resize selection handles. ///

public class DesignableControl { public Control Control { get; set; } = null!; public string ControlType { get; set; } = ""; public string Name { get; set; } = ""; public bool IsSelected { get; set; } public List ResizeHandles { get; set; } = new(); public Point[] HandlePoints { get; set; } = Array.Empty(); // Drag state public bool IsDragging { get; set; } public Point DragOffset { get; set; } // Resize state public int ActiveHandleIndex { get; set; } = -1; public Point ResizeStartPoint { get; set; } public Size OriginalSize { get; set; } public Point OriginalLocation { get; set; } public Rectangle Bounds => Control?.Bounds ?? Rectangle.Empty; public void CalculateHandles() { if (Control == null) return; int s = 7; var b = Control.Bounds; var canvas = Control.Parent?.Bounds ?? Rectangle.Empty; HandlePoints = new[] { new Point(b.Left, b.Top), // 0: TopLeft new Point(b.Right, b.Top), // 1: TopRight new Point(b.Left, b.Bottom), // 2: BottomLeft new Point(b.Right, b.Bottom), // 3: BottomRight new Point(b.Left + b.Width / 2, b.Top), // 4: Top new Point(b.Left + b.Width / 2, b.Bottom), // 5: Bottom new Point(b.Left, b.Top + b.Height / 2), // 6: Left new Point(b.Right, b.Top + b.Height / 2), // 7: Right }; ResizeHandles = HandlePoints .Select(p => new Rectangle(p.X - s / 2, p.Y - s / 2, s, s)) .ToList(); } public int HitTestResizeHandle(Point p) { CalculateHandles(); for (int i = 0; i < ResizeHandles.Count; i++) { if (ResizeHandles[i].Contains(p)) return i; } return -1; } public void ApplyResize(int handleIndex, Point current, int gridSize) { if (Control == null || handleIndex < 0) return; var b = Control.Bounds; int dx = current.X - ResizeStartPoint.X; int dy = current.Y - ResizeStartPoint.Y; int newLeft = b.Left, newTop = b.Top; int newWidth = b.Width, newHeight = b.Height; switch (handleIndex) { case 0: // TopLeft newLeft = OriginalLocation.X + dx; newTop = OriginalLocation.Y + dy; newWidth = OriginalSize.Width - dx; newHeight = OriginalSize.Height - dy; break; case 1: // TopRight newTop = OriginalLocation.Y + dy; newWidth = OriginalSize.Width + dx; newHeight = OriginalSize.Height - dy; break; case 2: // BottomLeft newLeft = OriginalLocation.X + dx; newWidth = OriginalSize.Width - dx; newHeight = OriginalSize.Height + dy; break; case 3: // BottomRight newWidth = OriginalSize.Width + dx; newHeight = OriginalSize.Height + dy; break; case 4: // Top newTop = OriginalLocation.Y + dy; newHeight = OriginalSize.Height - dy; break; case 5: // Bottom newHeight = OriginalSize.Height + dy; break; case 6: // Left newLeft = OriginalLocation.X + dx; newWidth = OriginalSize.Width - dx; break; case 7: // Right newWidth = OriginalSize.Width + dx; break; } newWidth = Math.Max(20, newWidth); newHeight = Math.Max(20, newHeight); newLeft = Math.Max(0, newLeft); newTop = Math.Max(0, newTop); if (gridSize > 0) { newLeft = (newLeft / gridSize) * gridSize; newTop = (newTop / gridSize) * gridSize; newWidth = Math.Max(gridSize, (newWidth / gridSize) * gridSize); newHeight = Math.Max(gridSize, (newHeight / gridSize) * gridSize); } Control.Bounds = new Rectangle(newLeft, newTop, newWidth, newHeight); Control.Invalidate(); } public void DrawSelection(Graphics g, Color selectionColor) { if (!IsSelected || Control == null) return; CalculateHandles(); // Selection border var b = Control.Bounds; using var pen = new Pen(selectionColor, 1) { DashStyle = DashStyle.Dash }; g.DrawRectangle(pen, b); // Resize handles foreach (var handle in ResizeHandles) { g.FillRectangle(Brushes.White, handle); g.DrawRectangle(new Pen(selectionColor), handle); } } } ``` ## 5. Designer Canvas (the main drawing surface) ```csharp using System.Drawing; using System.Drawing.Drawing2D; using System.Windows.Forms; namespace WinFormsDesigner; ///

/// The canvas where controls are placed, dragged, and resized. /// Handles grid, selection, drag/drop, and keyboard shortcuts. ///

public class DesignerCanvas : Control { public List DesignControls { get; } = new(); public DesignableControl? SelectedControl { get; private set; } public bool ShowGrid { get; set; } = true; public int GridSize { get; set; } = 8; public Color SelectionColor { get; set; } = Color.FromArgb(0, 120, 215); public Color CanvasBackColor { get; set; } = Color.White; public event Action? SelectionChanged; public event Action? ControlAdded; public event Action? StatusMessage; // Drag/drop palette item private string? _pendingControlType; private Point _pendingDropPoint; private bool _isDraggingNew; // Internal drag state private Point _dragStart; private bool _isMouseDown; private bool _isMoving; private DesignableControl? _dragControl; private int _activeResizeHandle = -1; // Marquee selection private Rectangle _marqueeRect; private bool _isMarqueeing; private Point _marqueeStart; // Clipboard private DesignableControl? _clipboard; public DesignerCanvas() { SetStyle( ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.OptimizedDoubleBuffer | ControlStyles.ResizeRedraw | ControlStyles.Selectable, true); AllowDrop = true; BackColor = Color.FromArgb(64, 64, 64); MinimumSize = new Size(100, 100); } ///

/// Set the control type that will be created on next click ///

public void SetPendingControl(string controlType) { _pendingControlType = controlType; _isDraggingNew = true; StatusMessage?.Invoke($"Click canvas to place: {controlType}"); Cursor = Cursors.Cross; } ///

/// Create a control at the specified type and position ///

public DesignableControl? CreateControl(string controlType, Point position, int defaultSize = -1) { Control control = controlType switch { "Button" => new Button { Text = "Button", Size = new Size(100, 30) }, "Label" => new Label { Text = "Label", Size = new Size(80, 23), AutoSize = false }, "TextBox" => new TextBox { Size = new Size(150, 23), Text = "" }, "RichTextBox" => new RichTextBox { Size = new Size(200, 100) }, "CheckBox" => new CheckBox { Text = "CheckBox", Size = new Size(100, 23) }, "RadioButton" => new RadioButton { Text = "Radio", Size = new Size(100, 23) }, "ComboBox" => new ComboBox { Size = new Size(150, 23), DropDownStyle = ComboBoxStyle.DropDownList }, "ListBox" => new ListBox { Size = new Size(150, 100) }, "Panel" => new Panel { Size = new Size(200, 150), BackColor = Color.WhiteSmoke }, "PictureBox" => new PictureBox { Size = new Size(100, 100), BorderStyle = BorderStyle.FixedSingle, BackColor = Color.LightGray }, "ProgressBar" => new ProgressBar { Size = new Size(200, 20), Value = 50 }, "TrackBar" => new TrackBar { Size = new Size(200, 40) }, "TabControl" => new TabControl { Size = new Size(300, 200) }, "DataGrid" => new DataGridView { Size = new Size(300, 150) }, "SplitContainer" => new SplitContainer { Size = new Size(400, 300), Orientation = Orientation.Vertical }, "NumericUpDown" => new NumericUpDown { Size = new Size(100, 23) }, "DateTimePicker" => new DateTimePicker { Size = new Size(200, 23) }, "TreeView" => new TreeView { Size = new Size(200, 200) }, "DateTime" => new DateTimePicker { Size = new Size(200, 23) }, "MenuStrip" => new MenuStrip { Size = new Size(400, 24) }, "ToolStrip" => new ToolStrip { Size = new Size(400, 25) }, "StatusStrip" => new StatusStrip { Size = new Size(400, 22) }, "LinkLabel" => new LinkLabel { Text = "LinkLabel", Size = new Size(80, 23), AutoSize = false }, "FlowLayoutPanel" => new FlowLayoutPanel { Size = new Size(300, 200), BackColor = Color.WhiteSmoke }, "DateTimeBox" => new DateTimePicker { Size = new Size(200, 23) }, _ => new Button { Text = controlType, Size = new Size(100, 30) } }; // Disable interaction during design control.Enabled = false; control.Visible = true; control.Location = SnapToGrid(position); control.Font = this.Font; control.Cursor = Cursors.SizeAll; control.BringToFront(); var parent = FindParentFor(controlType); Controls.Add(control); // Auto-add combo box items if (control is ComboBox cb) { cb.Items.AddRange(new[] { "Item 1", "Item 2", "Item 3" }); cb.SelectedIndex = 0; } else if (control is ListBox lb) { lb.Items.AddRange(new[] { "Item 1", "Item 2", "Item 3" }); } else if (control is TabControl tc && tc.TabPages.Count == 0) { tc.TabPages.Add("Tab 1"); tc.TabPages.Add("Tab 2"); } var dc = new DesignableControl { Control = control, ControlType = controlType, Name = GenerateUniqueName(controlType) }; DesignControls.Add(dc); SelectControl(dc); ControlAdded?.Invoke(); StatusMessage?.Invoke($"Added {controlType} at {control.Location}"); Invalidate(); return dc; } private Control FindParentFor(string type) { // Panel types can contain other controls if (type is "Panel" or "GroupBox" or "Tab") return this; return this; } private string GenerateUniqueName(string type) { string prefix = type.Replace(" ", ""); int count = 1; string name; do { name = prefix + count++; } while (DesignControls.Any(d => d.Name == name)); return name; } public void SelectControl(DesignableControl? dc) { if (SelectedControl != null) { SelectedControl.IsSelected = false; SelectedControl.Control?.Invalidate(); } SelectedControl = dc; if (dc != null) { dc.IsSelected = true; dc.Control?.BringToFront(); dc.Control?.Invalidate(); dc.CalculateHandles(); } SelectionChanged?.Invoke(dc); Invalidate(); } public void DeselectAll() { SelectControl(null); } private Point SnapToGrid(Point p) { if (GridSize <= 0) return p; return new Point( (p.X / GridSize) * GridSize, (p.Y / GridSize) * GridSize); } private Rectangle SnapToGrid(Rectangle r) { if (GridSize <= 0) return r; return new Rectangle( (r.X / GridSize) * GridSize, (r.Y / GridSize) * GridSize, Math.Max(GridSize, (r.Width / GridSize) * GridSize), Math.Max(GridSize, (r.Height / GridSize) * GridSize)); } protected override void OnMouseDown(MouseEventArgs e) { base.OnMouseDown(e); Focus(); _isMouseDown = true; _dragStart = e.Location; if (e.Button == MouseButtons.Left) { // Create new control if pending if (_pendingControlType != null && _pendingDropPoint == Point.Empty) { _pendingDropPoint = e.Location; var pt = new Point(e.X - 5, e.Y - 5); CreateControl(_pendingControlType, pt); _pendingControlType = null; _isDraggingNew = false; _pendingDropPoint = Point.Empty; Cursor = Cursors.Default; return; } // Hit test resize handles if (SelectedControl != null) { var handleIdx = SelectedControl.HitTestResizeHandle(e.Location); if (handleIdx >= 0) { _activeResizeHandle = handleIdx; SelectedControl.ActiveHandleIndex = handleIdx; SelectedControl.ResizeStartPoint = e.Location; SelectedControl.OriginalSize = SelectedControl.Control.Size; SelectedControl.OriginalLocation = SelectedControl.Control.Location; Cursor = GetResizeCursor(handleIdx); StatusMessage?.Invoke("Resizing..."); return; } } // Hit test existing controls var hitControl = HitTestControl(e.Location); if (hitControl != null) { SelectControl(hitControl); _dragControl = hitControl; _isMoving = true; hitControl.IsDragging = true; hitControl.DragOffset = new Point( e.X - hitControl.Control.Location.X, e.Y - hitControl.Control.Location.Y); Cursor = Cursors.SizeAll; } else { // Start marquee selection _isMarqueeing = true; _marqueeStart = e.Location; _marqueeRect = Rectangle.Empty; DeselectAll(); } } else if (e.Button == MouseButtons.Right) { // Right-click to deselect DeselectAll(); } Invalidate(); } protected override void OnMouseMove(MouseEventArgs e) { base.OnMouseMove(e); if (_isMouseDown && _activeResizeHandle >= 0 && SelectedControl != null) { SelectedControl.ApplyResize(_activeResizeHandle, e.Location, 0); Invalidate(); return; } if (_isMouseDown && _isMoving && _dragControl != null) { int newX = e.X - _dragControl.DragOffset.X; int newY = e.Y - _dragControl.DragOffset.Y; newX = Math.Max(0, newX); newY = Math.Max(0, newY); if (GridSize > 0) { newX = (newX / GridSize) * GridSize; newY = (newY / GridSize) * GridSize; } _dragControl.Control.Location = new Point(newX, newY); _dragControl.CalculateHandles(); StatusMessage?.Invoke($"Position: {newX}, {newY}"); Invalidate(); return; } if (_isMouseDown && _isMarqueeing) { _marqueeRect = new Rectangle( Math.Min(_marqueeStart.X, e.X), Math.Min(_marqueeStart.Y, e.Y), Math.Abs(e.X - _marqueeStart.X), Math.Abs(e.Y - _marqueeStart.Y)); Invalidate(); return; } // Hover cursor for handles if (SelectedControl != null) { var idx = SelectedControl.HitTestResizeHandle(e.Location); if (idx >= 0) Cursor = GetResizeCursor(idx); else { var hit = HitTestControl(e.Location); if (hit == null) Cursor = Cursors.Default; } } } protected override void OnMouseUp(MouseEventArgs e) { base.OnMouseUp(e); _isMouseDown = false; _activeResizeHandle = -1; if (_dragControl != null) { _dragControl.IsDragging = false; _dragControl = null; _isMoving = false; } if (_isMarqueeing) { _isMarqueeing = false; ApplyMarqueeSelection(); } Cursor = Cursors.Default; Invalidate(); } protected override void OnMouseLeave(EventArgs e) { base.OnMouseLeave(e); if (_pendingControlType != null && !_isMouseDown) { // Keep cross cursor } } private DesignableControl? HitTestControl(Point p) { // Check from front to back (reverse order) for (int i = DesignControls.Count - 1; i >= 0; i--) { var dc = DesignControls[i]; if (dc.Control != null && dc.Control.Visible && dc.Control.Bounds.Contains(p)) return dc; } return null; } private void ApplyMarqueeSelection() { if (_marqueeRect.Width < 3 && _marqueeRect.Height < 3) return; var selected = DesignControls.Where(dc => _marqueeRect.IntersectsWith(dc.Bounds)).ToList(); if (selected.Count > 0) SelectControl(selected.Last()); } private Cursor GetResizeCursor(int handleIndex) { return handleIndex switch { 0 => Cursors.SizeNWSE, // TL 1 => Cursors.SizeNESW, // TR 2 => Cursors.SizeNESW, // BL 3 => Cursors.SizeNWSE, // BR 4 => Cursors.SizeNS, // Top 5 => Cursors.SizeNS, // Bottom 6 => Cursors.SizeWE, // Left 7 => Cursors.SizeWE, // Right _ => Cursors.Default }; } ///

/// Delete the selected control ///

public void DeleteSelected() { if (SelectedControl == null) return; RemoveControl(SelectedControl); DeselectAll(); StatusMessage?.Invoke("Deleted control"); } public void RemoveControl(DesignableControl dc) { Controls.Remove(dc.Control); DesignControls.Remove(dc); ControlAdded?.Invoke(); Invalidate(); } ///

/// Copy selected control to clipboard ///

public void CopySelected() { if (SelectedControl == null) return; _clipboard = SelectedControl; StatusMessage?.Invoke($"Copied {_clipboard.ControlType}"); } ///

/// Paste from clipboard ///

public void PasteFromClipboard() { if (_clipboard == null) return; var data = ControlToData(_clipboard); var pt = new Point( data.Bounds.X + 20, data.Bounds.Y + 20); var dc = CreateControl(_clipboard.ControlType, pt); if (dc != null) ApplyDataToControl(data, dc); StatusMessage?.Invoke("Pasted control"); } ///

/// Duplicate selected control ///

public void DuplicateSelected() { if (SelectedControl == null) return; var data = ControlToData(SelectedControl); data.Bounds = new Rectangle( data.Bounds.X + 20, data.Bounds.Y + 20, data.Bounds.Width, data.Bounds.Height); var dc = CreateControl(SelectedControl.ControlType, new Point(data.Bounds.X, data.Bounds.Y)); if (dc != null) ApplyDataToControl(data, dc); } ///

/// Clear all controls from canvas ///

public void ClearAll() { foreach (var dc in DesignControls.ToList()) Controls.Remove(dc.Control); DesignControls.Clear(); DeselectAll(); ControlAdded?.Invoke(); Invalidate(); } ///

/// Serialize a designable control to ControlData ///

public ControlData ControlToData(DesignableControl dc) { var c = dc.Control; return new ControlData { ControlType = dc.ControlType, Name = dc.Name, Text = c is Button b ? b.Text : c is Label l ? l.Text : c is TextBox t ? t.Text : c is CheckBox cb ? cb.Text : c is RadioButton rb ? rb.Text : c is LinkLabel ll ? ll.Text : c is NumericUpDown nu ? nu.Value.ToString() : "", Bounds = c.Bounds, ForeColor = c.ForeColor, BackColor = c.BackColor, Enabled = c.Enabled, Visible = c.Visible, FontSize = (int)c.Font.Size, FontFamily = c.Font.FontFamily.Name, Items = c is ComboBox cmb ? string.Join(";", cmb.Items.Cast()) : c is ListBox lb ? string.Join(";", lb.Items.Cast()) : "", Multiline = c is RichTextBox rt && rt.Multiline, }; } ///

/// Apply ControlData to an existing designable control ///

public void ApplyDataToControl(ControlData data, DesignableControl dc) { var c = dc.Control; dc.Name = data.Name; c.Bounds = data.Bounds; c.ForeColor = data.ForeColor; c.BackColor = data.BackColor; c.Enabled = data.Enabled; c.Visible = data.Visible; try { c.Font = new Font(data.FontFamily, data.FontSize); } catch { } if (!string.IsNullOrEmpty(data.Text)) { switch (c) { case Button b: b.Text = data.Text; break; case Label l: l.Text = data.Text; break; case TextBox t: t.Text = data.Text; break; case CheckBox cb: cb.Text = data.Text; break; case RadioButton rb: rb.Text = data.Text; break; case LinkLabel ll: ll.Text = data.Text; break; case CheckBox c2: c2.Text = data.Text; break; } } if (!string.IsNullOrEmpty(data.Items)) { var items = data.Items.Split(';', StringSplitOptions.RemoveEmptyEntries); if (c is ComboBox cmb) { cmb.Items.Clear(); cmb.Items.AddRange(items); } if (c is ListBox lb) { lb.Items.Clear(); lb.Items.AddRange(items); } } dc.CalculateHandles(); } ///

/// Nudge selected control by offset ///

public void NudgeSelected(int dx, int dy) { if (SelectedControl?.Control == null) return; var loc = SelectedControl.Control.Location; int nx = Math.Max(0, loc.X + dx); int ny = Math.Max(0, loc.Y + dy); SelectedControl.Control.Location = new Point(nx, ny); SelectedControl.CalculateHandles(); StatusMessage?.Invoke($"Position: {nx}, {ny}"); Invalidate(); } ///

/// Change z-order of selected control ///

public void BringToFrontSelected() { SelectedControl?.Control?.BringToFront(); Invalidate(); } public void SendToBackSelected() { SelectedControl?.Control?.SendToBack(); Invalidate(); } ///

/// Keyboard handling ///

protected override bool ProcessCmdKey(ref Message msg, Keys keyData) { switch (keyData) { case Keys.Delete: DeleteSelected(); return true; case Keys.Control | Keys.C: CopySelected(); return true; case Keys.Control | Keys.V: PasteFromClipboard(); return true; case Keys.Control | Keys.D: DuplicateSelected(); return true; case Keys.Control | Keys.Z: // Undo would go here return true; case Keys.Left: NudgeSelected(-1, 0); return true; case Keys.Right: NudgeSelected(1, 0); return true; case Keys.Up: NudgeSelected(0, -1); return true; case Keys.Down: NudgeSelected(0, 1); return true; case Keys.Control | Keys.Left: NudgeSelected(-GridSize, 0); return true; case Keys.Control | Keys.Right: NudgeSelected(GridSize, 0); return true; case Keys.Control | Keys.Up: NudgeSelected(0, -GridSize); return true; case Keys.Control | Keys.Down: NudgeSelected(0, GridSize); return true; case Keys.Shift | Keys.Left: NudgeSelected(-GridSize, 0); return true; case Keys.Shift | Keys.Right: NudgeSelected(GridSize, 0); return true; case Keys.Shift | Keys.Up: NudgeSelected(0, -GridSize); return true; case Keys.Shift | Keys.Down: NudgeSelected(0, GridSize); return true; case Keys.Control | Keys.B: BringToFrontSelected(); return true; case Keys.Control | Keys.Shift | Keys.B: SendToBackSelected(); return true; case Keys.Escape: DeselectAll(); _pendingControlType = null; Cursor = Cursors.Default; return true; } return base.ProcessCmdKey(ref msg, keyData); } ///

/// Paint the canvas ///

protected override void OnPaint(PaintEventArgs e) { base.OnPaint(e); var g = e.Graphics; g.SmoothingMode = SmoothingMode.AntiAlias; // Draw form-like canvas area var formRect = new Rectangle(10, 10, Width - 20, Height - 20); g.FillRectangle(Brushes.WhiteSmoke, formRect); g.DrawRectangle(Pens.Gray, formRect); // Draw grid if (ShowGrid && GridSize > 0) { using var gridPen = new Pen(Color.FromArgb(220, 220, 220)); for (int x = formRect.Left; x <= formRect.Right; x += GridSize) g.DrawLine(gridPen, x, formRect.Top, x, formRect.Bottom); for (int y = formRect.Top; y <= formRect.Bottom; y += GridSize) g.DrawLine(gridPen, formRect.Left, y, formRect.Right, y); } // Draw selection foreach (var dc in DesignControls) { if (dc.IsSelected) dc.DrawSelection(g, SelectionColor); } // Draw marquee if (_isMarqueeing && _marqueeRect.Width > 0) { using var marqueePen = new Pen(SelectionColor, 1) { DashStyle = DashStyle.Dash }; g.FillRectangle(new SolidBrush(Color.FromArgb(30, SelectionColor)), _marqueeRect); g.DrawRectangle(marqueePen, _marqueeRect); } } protected override void OnPaintBackground(PaintEventArgs e) { // Dark background outside canvas e.Graphics.Clear(BackColor); } } ``` ## 6. Control Palette (Toolbox) ```csharp using System.Drawing; using System.Windows.Forms; namespace WinFormsDesigner; ///

/// Left-side palette listing all available controls to drag onto canvas ///

public class ControlPalette : UserControl { private readonly FlowLayoutPanel _panel; private readonly TextBox _searchBox; public event Action? ControlTypeSelected; private readonly (string Type, string Icon, string Category)[] _controls = { // Basic ("Button", "☐", "Basic"), ("Label", "≡", "Basic"), ("TextBox", "▭", "Basic"), ("CheckBox", "☑", "Basic"), ("RadioButton", "◉", "Basic"), ("LinkLabel", "🔗", "Basic"), // Collections ("ComboBox", "▼", "Collections"), ("ListBox", "≡", "Collections"), ("CheckedListBox","☑", "Collections"), ("TreeView", "🌲", "Collections"), ("ListView", "≡", "Collections"), ("NumericUpDown","🔢", "Collections"), // Layout ("Panel", "▣", "Layout"), ("TabControl", "📑", "Layout"), ("FlowLayoutPanel","≡", "Layout"), ("SplitContainer","⇔", "Layout"), ("TableLayoutPanel","▦", "Layout"), ("GroupBox", "▨", "Layout"), // Data ("DataGridView", "▦", "Data"), ("DataGrid", "▦", "Data"), ("RichTextBox", "≡", "Data"), ("ProgressBar", "▰", "Data"), ("TrackBar", "━", "Data"), ("ProgressBar2", "▰", "Data"), // Components ("PictureBox", "🖼", "Components"), ("DateTimePicker","📅", "Components"), ("Calendar", "📅", "Components"), // Menus & Toolbars ("MenuStrip", "☰", "Menus"), ("ToolStrip", "☰", "Menus"), ("StatusStrip", "≡", "Menus"), ("ContextMenuStrip","☰", "Menus"), }; public ControlPalette() { Width = 200; BackColor = Color.FromArgb(51, 51, 51); BorderStyle = BorderStyle.None; // Search box _searchBox = new TextBox { Dock = DockStyle.Top, Height = 25, BackColor = Color.FromArgb(68, 68, 68), ForeColor = Color.White, Font = new Font("Segoe UI", 9), PlaceholderText = "Search controls...", Margin = new Padding(5), BorderStyle = BorderStyle.FixedSingle, }; _searchBox.TextChanged += (s, e) => RebuildPalette(_searchBox.Text); // Title var title = new Label { Text = "📋 Toolbox", Dock = DockStyle.Top, Height = 30, ForeColor = Color.White, Font = new Font("Segoe UI", 10, FontStyle.Bold), BackColor = Color.FromArgb(40, 40, 40), TextAlign = ContentAlignment.MiddleLeft, Padding = new Padding(8, 0, 0, 0), }; // Scrollable panel _panel = new FlowLayoutPanel { Dock = DockStyle.Fill, AutoScroll = true, BackColor = Color.FromArgb(51, 51, 51), Padding = new Padding(5), FlowDirection = FlowDirection.TopDown, WrapContents = false, }; Controls.Add(title); Controls.Add(_searchBox); Controls.Add(_panel); RebuildPalette(""); } private void RebuildPalette(string filter) { _panel.SuspendLayout(); _panel.Controls.Clear(); string? lastCategory = null; foreach (var (type, icon, category) in _controls) { if (!string.IsNullOrWhiteSpace(filter) && !type.Contains(filter, StringComparison.OrdinalIgnoreCase)) continue; if (lastCategory != category) { var catLabel = new Label { Text = $" {category}", Font = new Font("Segoe UI", 8, FontStyle.Bold), ForeColor = Color.FromArgb(150, 150, 150), Width = _panel.Width - 15, Height = 22, TextAlign = ContentAlignment.MiddleLeft, }; _panel.Controls.Add(catLabel); lastCategory = category; } var btn = CreatePaletteButton(type, icon); _panel.Controls.Add(btn); } _panel.ResumeLayout(); } private Button CreatePaletteButton(string type, string icon) { var btn = new Button { Text = $"{icon} {type}", Width = _panel.Width - 20, Height = 30, FlatStyle = FlatStyle.Flat, BackColor = Color.FromArgb(62, 62, 66), ForeColor = Color.FromArgb(220, 220, 220), Font = new Font("Segoe UI", 8.5f), TextAlign = ContentAlignment.MiddleLeft, Margin = new Padding(2, 1, 2, 1), Cursor = Cursors.Hand, Tag = type, }; btn.FlatAppearance.BorderSize = 0; btn.FlatAppearance.MouseOverBackColor = Color.FromArgb(0, 120, 215); btn.FlatAppearance.MouseDownBackColor = Color.FromArgb(0, 90, 170); // Click to select tool, or double-click to place immediately btn.Click += (s, e) => { ControlTypeSelected?.Invoke(type); }; // Allow drag from palette to canvas btn.MouseDown += (s, e) => { if (e.Button == MouseButtons.Left) { btn.DoDragDrop(type, DragDropEffects.Copy); } }; return btn; } } ``` ## 7. Property Grid Panel ```csharp using System.Drawing; using System.Windows.Forms; namespace WinFormsDesigner; ///

/// Right-side panel that shows properties of the selected control ///

public class PropertyGridPanel : UserControl { private readonly TabControl _tabControl; private readonly PropertyGrid _propertyGrid; private readonly TextBox _nameBox; private readonly ComboBox _typeBox; private DesignableControl? _currentControl; private ProjectData? _projectData; public event Action? PropertyChanged; public event Action? StatusMessage; public PropertyGridPanel() { Width = 280; BackColor = Color.FromArgb(40, 40, 40); BorderStyle = BorderStyle.None; // Title var title = new Label { Text = "⚙ Properties", Dock = DockStyle.Top, Height = 30, ForeColor = Color.White, Font = new Font("Segoe UI", 10, FontStyle.Bold), BackColor = Color.FromArgb(35, 35, 35), TextAlign = ContentAlignment.MiddleLeft, Padding = new Padding(8, 0, 0, 0), }; // Tabs: Properties / Events / Layout _tabControl = new TabControl { Dock = DockStyle.Fill, BackColor = Color.FromArgb(40, 40, 40), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), Padding = new Point(8, 4), }; // Properties tab var propTab = new TabPage("Properties") { BackColor = Color.FromArgb(40, 40, 40), ForeColor = Color.White, }; _propertyGrid = new PropertyGrid { Dock = DockStyle.Fill, HelpVisible = false, ToolbarVisible = false, BackColor = Color.FromArgb(40, 40, 40), ForeColor = Color.White, CategoryForeColor = Color.FromArgb(180, 180, 180), LineColor = Color.FromArgb(60, 60, 60), PropertySort = PropertySort.Categorized, Font = new Font("Segoe UI", 8.5f), }; propTab.Controls.Add(_propertyGrid); _tabControl.TabPages.Add(propTab); // Quick Edit tab var quickTab = new TabPage("Quick Edit") { BackColor = Color.FromArgb(40, 40, 40), ForeColor = Color.White, }; BuildQuickEditPanel(quickTab); _tabControl.TabPages.Add(quickTab); // Form tab var formTab = new TabPage("Form") { BackColor = Color.FromArgb(40, 40, 40), ForeColor = Color.White, }; BuildFormPropertiesPanel(formTab); _tabControl.TabPages.Add(formTab); Controls.Add(title); Controls.Add(_tabControl); } private void BuildQuickEditPanel(TabPage tab) { var layout = new TableLayoutPanel { Dock = DockStyle.Fill, AutoScroll = true, BackColor = Color.FromArgb(40, 40, 40), ColumnCount = 2, Padding = new Padding(5), }; layout.ColumnStyles.Add(new ColumnStyle(SizeType.Absolute, 90)); layout.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 100)); // Name AddRow(layout, "Name:", _nameBox = new TextBox { BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), BorderStyle = BorderStyle.FixedSingle, }); // Type (read-only) AddRow(layout, "Type:", _typeBox = new ComboBox { DropDownStyle = ComboBoxStyle.DropDownList, BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, Enabled = false, Font = new Font("Segoe UI", 8.5f), }); // Text var textBox = new TextBox { BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), BorderStyle = BorderStyle.FixedSingle, Tag = "text", }; AddRow(layout, "Text:", textBox); textBox.TextChanged += (s, e) => { if (_currentControl?.Control == null) return; var c = _currentControl.Control; if (c is Button b) b.Text = textBox.Text; else if (c is Label l) l.Text = textBox.Text; else if (c is TextBox t) t.Text = textBox.Text; else if (c is CheckBox cb) cb.Text = textBox.Text; else if (c is RadioButton rb) rb.Text = textBox.Text; else if (c is LinkLabel ll) ll.Text = textBox.Text; c.Invalidate(); PropertyChanged?.Invoke("Text"); }; // X, Y var xBox = new NumericUpDown { Minimum = 0, Maximum = 9999, BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), }; var yBox = new NumericUpDown { Minimum = 0, Maximum = 9999, BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), }; AddRow(layout, "X:", xBox); AddRow(layout, "Y:", yBox); xBox.ValueChanged += (s, e) => { if (_currentControl?.Control == null) return; _currentControl.Control.Location = new Point((int)xBox.Value, _currentControl.Control.Location.Y); _currentControl.CalculateHandles(); }; yBox.ValueChanged += (s, e) => { if (_currentControl?.Control == null) return; _currentControl.Control.Location = new Point(_currentControl.Control.Location.X, (int)yBox.Value); _currentControl.CalculateHandles(); }; // Width, Height var wBox = new NumericUpDown { Minimum = 10, Maximum = 9999, BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), }; var hBox = new NumericUpDown { Minimum = 10, Maximum = 9999, BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), }; AddRow(layout, "Width:", wBox); AddRow(layout, "Height:", hBox); wBox.ValueChanged += (s, e) => { if (_currentControl?.Control == null) return; var b = _currentControl.Control.Bounds; _currentControl.Control.Size = new Size((int)wBox.Value, b.Height); _currentControl.CalculateHandles(); }; hBox.ValueChanged += (s, e) => { if (_currentControl?.Control == null) return; var b = _currentControl.Control.Bounds; _currentControl.Control.Size = new Size(b.Width, (int)hBox.Value); _currentControl.CalculateHandles(); }; // ForeColor var foreBtn = new Button { Text = "Choose...", BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, FlatStyle = FlatStyle.Flat, Height = 25, }; AddRow(layout, "ForeColor:", foreBtn); foreBtn.Click += (s, e) => { if (_currentControl?.Control == null) return; using var cd = new ColorDialog { Color = _currentControl.Control.ForeColor }; if (cd.ShowDialog() == DialogResult.OK) { _currentControl.Control.ForeColor = cd.Color; _currentControl.Control.Invalidate(); } }; // BackColor var backBtn = new Button { Text = "Choose...", BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, FlatStyle = FlatStyle.Flat, Height = 25, }; AddRow(layout, "BackColor:", backBtn); backBtn.Click += (s, e) => { if (_currentControl?.Control == null) return; using var cd = new ColorDialog { Color = _currentControl.Control.BackColor }; if (cd.ShowDialog() == DialogResult.OK) { _currentControl.Control.BackColor = cd.Color; _currentControl.Control.Invalidate(); } }; // Font size var fontBox = new NumericUpDown { Minimum = 6, Maximum = 72, Value = 9, BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), }; AddRow(layout, "FontSize:", fontBox); fontBox.ValueChanged += (s, e) => { if (_currentControl?.Control == null) return; var c = _currentControl.Control; c.Font = new Font(c.Font.FontFamily, (float)fontBox.Value, c.Font.Style); c.Invalidate(); }; // Visible / Enabled var visibleCheck = new CheckBox { Text = "Visible", ForeColor = Color.White, BackColor = Color.FromArgb(40, 40, 40), CheckState = CheckState.Checked, }; AddRow(layout, "Visible:", visibleCheck); visibleCheck.CheckedChanged += (s, e) => { if (_currentControl?.Control == null) return; _currentControl.Control.Visible = visibleCheck.Checked; PropertyChanged?.Invoke("Visible"); }; var enabledCheck = new CheckBox { Text = "Enabled", ForeColor = Color.White, BackColor = Color.FromArgb(40, 40, 40), CheckState = CheckState.Checked, }; AddRow(layout, "Enabled:", enabledCheck); enabledCheck.CheckedChanged += (s, e) => { if (_currentControl?.Control == null) return; _currentControl.Control.Enabled = enabledCheck.Checked; PropertyChanged?.Invoke("Enabled"); }; // Store references for updates tab.Tag = new Dictionary { ["name"] = _nameBox, ["text"] = textBox, ["x"] = xBox, ["y"] = yBox, ["w"] = wBox, ["h"] = hBox, ["fontSize"] = fontBox, ["visible"] = visibleCheck, ["enabled"] = enabledCheck, }; tab.Controls.Add(layout); } private void BuildFormPropertiesPanel(TabPage tab) { var layout = new TableLayoutPanel { Dock = DockStyle.Fill, AutoScroll = true, BackColor = Color.FromArgb(40, 40, 40), ColumnCount = 2, Padding = new Padding(5), }; layout.ColumnStyles.Add(new ColumnStyle(SizeType.Absolute, 90)); layout.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 100)); AddRow(layout, "Form Text:", new TextBox { BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), BorderStyle = BorderStyle.FixedSingle, }); var formSizeW = new NumericUpDown { Minimum = 200, Maximum = 9999, Value = 800, BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, }; AddRow(layout, "Width:", formSizeW); var formSizeH = new NumericUpDown { Minimum = 150, Maximum = 9999, Value = 600, BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, }; AddRow(layout, "Height:", formSizeH); var backColorBtn = new Button { Text = "Choose...", BackColor = Color.FromArgb(60, 60, 60), ForeColor = Color.White, FlatStyle = FlatStyle.Flat, Height = 25, }; AddRow(layout, "BackColor:", backColorBtn); var gridCheck = new CheckBox { Text = "Show Grid", ForeColor = Color.White, BackColor = Color.FromArgb(40, 40, 40), Checked = true, }; AddRow(layout, "", gridCheck); tab.Controls.Add(layout); } private void AddRow(TableLayoutPanel tp, string label, Control control) { var lbl = new Label { Text = label, ForeColor = Color.FromArgb(200, 200, 200), Font = new Font("Segoe UI", 8.5f), Dock = DockStyle.Fill, TextAlign = ContentAlignment.MiddleLeft, BackColor = Color.FromArgb(40, 40, 40), }; tp.Controls.Add(lbl); tp.Controls.Add(control); } ///

/// Called when a control is selected on canvas ///

public void ShowProperties(DesignableControl? dc) { _currentControl = dc; if (dc == null) { _propertyGrid.SelectedObject = null; _nameBox.Text = ""; _typeBox.Text = ""; StatusMessage?.Invoke("No selection"); return; } // Setup PropertyGrid with dynamic object _propertyGrid.SelectedObject = new ControlPropertyAdapter(dc); _nameBox.Text = dc.Name; _typeBox.Text = dc.ControlType; // Update quick edit if (_tabControl.TabPages.Count > 1 && _tabControl.TabPages[1].Tag is Dictionary refs) { var c = dc.Control; if (refs["text"] is TextBox txt) txt.Text = c is Button b ? b.Text : c is Label l ? l.Text : c is TextBox t ? t.Text : c is CheckBox cb ? cb.Text : c is RadioButton rb ? rb.Text : ""; if (refs["x"] is NumericUpDown nx) nx.Value = c.Location.X; if (refs["y"] is NumericUpDown ny) ny.Value = c.Location.Y; if (refs["w"] is NumericUpDown nw) nw.Value = c.Width; if (refs["h"] is NumericUpDown nh) nh.Value = c.Height; if (refs["fontSize"] is NumericUpDown fs) fs.Value = (int)c.Font.Size; if (refs["visible"] is CheckBox vc) vc.Checked = c.Visible; if (refs["enabled"] is CheckBox ec) ec.Checked = c.Enabled; } StatusMessage?.Invoke($"Selected: {dc.Name} ({dc.ControlType})"); } } ///

/// Adapter to expose Control properties to PropertyGrid ///

public class ControlPropertyAdapter { private readonly DesignableControl _dc; public ControlPropertyAdapter(DesignableControl dc) { _dc = dc; } [Category("Design")] public string Name { get => _dc.Name; set { _dc.Name = value; } } [Category("Appearance")] public string Text { get => _dc.Control switch { Button b => b.Text, Label l => l.Text, TextBox t => t.Text, CheckBox cb => cb.Text, RadioButton rb => rb.Text, LinkLabel ll => ll.Text, _ => "" }; set { switch (_dc.Control) { case Button b: b.Text = value; break; case Label l: l.Text = value; break; case TextBox t: t.Text = value; break; case CheckBox cb: cb.Text = value; break; case RadioButton rb: rb.Text = value; break; case LinkLabel ll: ll.Text = value; break; } _dc.Control?.Invalidate(); } } [Category("Layout")] public int X { get => _dc.Control?.Location.X ?? 0; set { if (_dc.Control != null) { var p = _dc.Control.Location; _dc.Control.Location = new Point(value, p.Y); _dc.CalculateHandles(); } } } [Category("Layout")] public int Y { get => _dc.Control?.Location.Y ?? 0; set { if (_dc.Control != null) { var p = _dc.Control.Location; _dc.Control.Location = new Point(p.X, value); _dc.CalculateHandles(); } } } [Category("Layout")] public int Width { get => _dc.Control?.Width ?? 0; set { if (_dc.Control != null) { var s = _dc.Control.Size; _dc.Control.Size = new Size(value, s.Height); _dc.CalculateHandles(); } } } [Category("Layout")] public int Height { get => _dc.Control?.Height ?? 0; set { if (_dc.Control != null) { var s = _dc.Control.Size; _dc.Control.Size = new Size(s.Width, value); _dc.CalculateHandles(); } } } [Category("Appearance")] public Color ForeColor { get => _dc.Control?.ForeColor ?? Color.Black; set { if (_dc.Control != null) { _dc.Control.ForeColor = value; _dc.Control.Invalidate(); } } } [Category("Appearance")] public Color BackColor { get => _dc.Control?.BackColor ?? Color.Control; set { if (_dc.Control != null) { _dc.Control.BackColor = value; _dc.Control.Invalidate(); } } } [Category("Font")] public int FontSize { get => (int)(_dc.Control?.Font.Size ?? 9); set { if (_dc.Control != null) { var f = _dc.Control.Font; _dc.Control.Font = new Font(f.FontFamily, value, f.Style); _dc.Control.Invalidate(); } } } [Category("Behavior")] public bool Enabled { get => _dc.Control?.Enabled ?? true; set { if (_dc.Control != null) _dc.Control.Enabled = value; } } [Category("Behavior")] public bool Visible { get => _dc.Control?.Visible ?? true; set { if (_dc.Control != null) _dc.Control.Visible = value; } } } ``` ## 8. Project Manager (Save / Load / Export) ```csharp using System.Drawing; using System.Text.Json; using System.Text.Json.Serialization; using System.Windows.Forms; namespace WinFormsDesigner; ///

/// Handles saving, loading, and exporting designer projects ///

public static class ProjectManager { private static readonly JsonSerializerOptions JsonOptions = new() { WriteIndented = true, Converters = { new JsonStringEnumConverter() } }; ///

/// Serialize the current canvas state to ProjectData ///

public static ProjectData CaptureState( DesignerCanvas canvas, string projectName = "Untitled", string formText = "Form1", Size? formSize = null) { var data = new ProjectData { ProjectName = projectName, FormText = formText, FormSize = formSize ?? new Size(canvas.Width, canvas.Height), FormBackColor = canvas.CanvasBackColor, }; foreach (var dc in canvas.DesignControls) { data.Controls.Add(canvas.ControlToData(dc)); } return data; } ///

/// Restore canvas state from ProjectData ///

public static void RestoreState(DesignerCanvas canvas, ProjectData data) { canvas.ClearAll(); foreach (var cd in data.Controls) { var dc = canvas.CreateControl( cd.ControlType, new Point(cd.Bounds.X, cd.Bounds.Y)); if (dc != null) canvas.ApplyDataToControl(cd, dc); } canvas.CanvasBackColor = data.FormBackColor; canvas.DeselectAll(); canvas.Invalidate(); } ///

/// Save project to a JSON file ///

public static string? SaveProject( DesignerCanvas canvas, string defaultName = "MyForm") { using var dialog = new SaveFileDialog { Filter = "Designer Project (*.wfdproj)|*.wfdproj|JSON Files (*.json)|*.json", FileName = defaultName + ".wfdproj", Title = "Save Designer Project", }; if (dialog.ShowDialog() != DialogResult.OK) return null; var data = CaptureState(canvas, Path.GetFileNameWithoutExtension(dialog.FileName)); var json = JsonSerializer.Serialize(data, JsonOptions); File.WriteAllText(dialog.FileName, json); return dialog.FileName; } ///

/// Load project from a JSON file ///

public static string? LoadProject(DesignerCanvas canvas) { using var dialog = new OpenFileDialog { Filter = "Designer Project (*.wfdproj;*.json)|*.wfdproj;*.json|All Files (*.*)|*.*", Title = "Open Designer Project", }; if (dialog.ShowDialog() != DialogResult.OK) return null; try { var json = File.ReadAllText(dialog.FileName); var data = JsonSerializer.Deserialize(json, JsonOptions); if (data != null) { RestoreState(canvas, data); return dialog.FileName; } } catch (Exception ex) { MessageBox.Show( $"Error loading project: {ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } return null; } ///

/// Export as C# code that generates the form ///

public static string? ExportToCSharp(DesignerCanvas canvas, string className = "MyForm") { using var dialog = new SaveFileDialog { Filter = "C# File (*.cs)|*.cs", FileName = className + ".cs", Title = "Export C# Code", }; if (dialog.ShowDialog() != DialogResult.OK) return null; var code = GenerateCSharpCode(canvas, className); File.WriteAllText(dialog.FileName, code); return dialog.FileName; } ///

/// Export as WinForms Designer .Designer.cs file ///

public static string? ExportToDesignerFile( DesignerCanvas canvas, string className = "MyForm") { using var dialog = new SaveFileDialog { Filter = "Designer File (*.Designer.cs)|*.Designer.cs|C# File (*.cs)|*.cs", FileName = className + ".Designer.cs", Title = "Export Designer File", }; if (dialog.ShowDialog() != DialogResult.OK) return null; var code = GenerateDesignerFile(canvas, className); File.WriteAllText(dialog.FileName, code); return dialog.FileName; } private static string GenerateCSharpCode(DesignerCanvas canvas, string className) { var sb = new System.Text.StringBuilder(); sb.AppendLine($"// Auto-generated by WinForms Designer"); sb.AppendLine($"using System;"); sb.AppendLine($"using System.Drawing;"); sb.AppendLine($"using System.Windows.Forms;"); sb.AppendLine(); sb.AppendLine($"namespace YourNamespace;"); sb.AppendLine(); sb.AppendLine($"public partial class {className} : Form"); sb.AppendLine("{"); sb.AppendLine($" public {className}()"); sb.AppendLine(" {"); sb.AppendLine(" InitializeComponent();"); sb.AppendLine(" }"); sb.AppendLine("}"); return sb.ToString(); } private static string GenerateDesignerFile(DesignerCanvas canvas, string className) { var sb = new System.Text.StringBuilder(); sb.AppendLine($"namespace YourNamespace;"); sb.AppendLine(); sb.AppendLine($"partial class {className}"); sb.AppendLine("{"); sb.AppendLine(" private System.ComponentModel.IContainer components = null;"); sb.AppendLine(); sb.AppendLine(" protected override void Dispose(bool disposing)"); sb.AppendLine(" {"); sb.AppendLine(" if (disposing && (components != null))"); sb.AppendLine(" {"); sb.AppendLine(" components.Dispose();"); sb.AppendLine(" }"); sb.AppendLine(" base.Dispose(disposing);"); sb.AppendLine(" }"); sb.AppendLine(); sb.AppendLine(" private void InitializeComponent()"); sb.AppendLine(" {"); sb.AppendLine(" this.SuspendLayout();"); sb.AppendLine(" //"); sb.AppendLine($" // {className}"); sb.AppendLine(" //"); sb.AppendLine($" this.Name = \"{className}\";"); sb.AppendLine($" this.Text = \"{className}\";"); sb.AppendLine($" this.Size = new System.Drawing.Size({canvas.Width}, {canvas.Height});"); sb.AppendLine(" "); foreach (var dc in canvas.DesignControls) { var c = dc.Control; var type = dc.ControlType; var safeType = type switch { "TextBox" => "System.Windows.Forms.TextBox", "Button" => "System.Windows.Forms.Button", "Label" => "System.Windows.Forms.Label", "CheckBox" => "System.Windows.Forms.CheckBox", "RadioButton" => "System.Windows.Forms.RadioButton", "ComboBox" => "System.Windows.Forms.ComboBox", "ListBox" => "System.Windows.Forms.ListBox", "Panel" => "System.Windows.Forms.Panel", "PictureBox" => "System.Windows.Forms.PictureBox", "ProgressBar" => "System.Windows.Forms.ProgressBar", "RichTextBox" => "System.Windows.Forms.RichTextBox", "NumericUpDown" => "System.Windows.Forms.NumericUpDown", "DateTimePicker" => "System.Windows.Forms.DateTimePicker", "LinkLabel" => "System.Windows.Forms.LinkLabel", _ => $"System.Windows.Forms.{type}" }; sb.AppendLine($" // {dc.Name}"); sb.AppendLine($" this.{dc.Name} = new {safeType}();"); string textVal = c is Button b ? b.Text : c is Label l ? l.Text : c is TextBox t ? t.Text : c is CheckBox cb ? cb.Text : c is RadioButton rb ? rb.Text : c is LinkLabel ll ? ll.Text : ""; if (!string.IsNullOrEmpty(textVal)) sb.AppendLine($" this.{dc.Name}.Text = \"{Escape(textVal)}\";"); sb.AppendLine($" this.{dc.Name}.Location = new System.Drawing.Point({c.Location.X}, {c.Location.Y});"); sb.AppendLine($" this.{dc.Name}.Size = new System.Drawing.Size({c.Width}, {c.Height});"); sb.AppendLine($" this.{dc.Name}.ForeColor = System.Drawing.Color.FromArgb({c.ForeColor.R}, {c.ForeColor.G}, {c.ForeColor.B});"); sb.AppendLine($" this.{dc.Name}.BackColor = System.Drawing.Color.FromArgb({c.BackColor.R}, {c.BackColor.G}, {c.BackColor.B});"); sb.AppendLine($" this.{dc.Name}.Font = new System.Drawing.Font(\"{c.Font.FontFamily.Name}\", {c.Font.Size:F1}F);"); sb.AppendLine($" this.{dc.Name}.Name = \"{dc.Name}\";"); sb.AppendLine($" ((System.ComponentModel.ISupportInitialize)(this.{dc.Name})).BeginInit();" is Control ? $" this.{dc.Name}Controls.Add(this.{dc.Name});" : $" this.Controls.Add(this.{dc.Name});"); sb.AppendLine($" ((System.ComponentModel.ISupportInitialize)(this.{dc.Name})).EndInit();" is Control ? $" ((System.ComponentModel.ISupportInitialize)(this.{dc.Name})).EndInit();" : ""); sb.AppendLine(); } sb.AppendLine(" this.ResumeLayout(false);"); sb.AppendLine(" this.PerformLayout();"); sb.AppendLine(" }"); sb.AppendLine(); // Field declarations sb.AppendLine(" #region Windows Form Designer generated code"); foreach (var dc in canvas.DesignControls) { sb.AppendLine($" private System.Windows.Forms.{dc.ControlType} {dc.Name};"); } sb.AppendLine(" #endregion"); sb.AppendLine("}"); return sb.ToString(); } private static string Escape(string s) => s.Replace("\\", "\\\\").Replace("\"", "\\\"").Replace("\n", "\\n"); } ``` ## 9. Main Form (the designer window) ```csharp using System.Drawing; using System.Drawing.Drawing2D; using System.Windows.Forms; namespace WinFormsDesigner; ///

/// Main designer window with toolbar, canvas, palette, and property grid ///

public partial class MainForm : Form { // Core components private DesignerCanvas _canvas = null!; private ControlPalette _palette = null!; private PropertyGridPanel _propsPanel = null!; // Toolbar private ToolStrip _toolStrip = null!; private StatusStrip _statusStrip = null!; private ToolStripStatusLabel _statusLabel = null!; private ToolStripStatusLabel _positionLabel = null!; private ToolStripStatusLabel _selectionLabel = null!; // State private string _currentFile = ""; private bool _isDirty; public MainForm() { InitializeComponent(); SetupUI(); SetupStatusbar(); } private void InitializeComponent() { Text = "WinForms Visual Designer"; Size = new Size(1400, 900); StartPosition = FormStartPosition.CenterScreen; MinimumSize = new Size(1000, 700); BackColor = Color.FromArgb(45, 45, 45); try { Icon = SystemIcons.Application; } catch { } } private void SetupUI() { SuspendLayout(); // === TOOLBAR === _toolStrip = BuildToolbar(); Controls.Add(_toolStrip); // === LEFT: Control Palette === _palette = new ControlPalette { Dock = DockStyle.Left }; _palette.ControlTypeSelected += OnPaletteTypeSelected; Controls.Add(_palette); // === RIGHT: Property Grid === _propsPanel = new PropertyGridPanel { Dock = DockStyle.Right }; Controls.Add(_propsPanel); // === CENTER: Designer Canvas (wrapped in panel) === var canvasPanel = new Panel { Dock = DockStyle.Fill, AutoScroll = true, BackColor = Color.FromArgb(64, 64, 64), Padding = new Padding(20), }; _canvas = new DesignerCanvas { Size = new Size(800, 600), Anchor = AnchorStyles.None, }; // Wire up canvas events _canvas.SelectionChanged += OnSelectionChanged; _canvas.StatusMessage += msg => _statusLabel.Text = msg; _canvas.ControlAdded += () => { _isDirty = true; UpdateTitle(); }; canvasPanel.Controls.Add(_canvas); Controls.Add(canvasPanel); // === STATUS BAR === SetupStatusbar(); Controls.Add(_statusStrip); ResumeLayout(true); } private ToolStrip BuildToolbar() { var ts = new ToolStrip { Dock = DockStyle.Top, BackColor = Color.FromArgb(35, 35, 35), ForeColor = Color.White, Font = new Font("Segoe UI", 8.5f), GripStyle = ToolStripGripStyle.Hidden, Padding = new Padding(4, 2, 4, 2), RenderMode = ToolStripRenderMode.Professional, }; // Style the toolbar ts.Renderer = new DarkToolStripRenderer(); void AddButton(string text, string? tooltip, Action action, bool separator = false) { if (separator) ts.Items.Add(new ToolStripSeparator()); var btn = new ToolStripButton(text) { DisplayStyle = ToolStripItemDisplayStyle.Text, ForeColor = Color.FromArgb(220, 220, 220), AutoSize = true, Padding = new Padding(4, 2, 4, 2), ToolTipText = tooltip ?? "", }; btn.Click += (s, e) => action(); ts.Items.Add(btn); } // File operations AddButton("📂 New", "New Project (Ctrl+N)", NewProject); AddButton("📁 Open", "Open Project (Ctrl+O)", OpenProject); AddButton("💾 Save", "Save Project (Ctrl+S)", SaveProject); AddButton("💾 Save As", "Save As (Ctrl+Shift+S)", SaveProjectAs, separator: true); // Edit operations AddButton("📋 Copy", "Copy (Ctrl+C)", () => _canvas.CopySelected()); AddButton("📋 Paste", "Paste (Ctrl+V)", () => _canvas.PasteFromClipboard()); AddButton("📄 Duplicate", "Duplicate (Ctrl+D)", () => _canvas.DuplicateSelected()); AddButton("🗑 Delete", "Delete (Delete)", () => _canvas.DeleteSelected(), separator: true); // View operations AddButton("📐 Grid", "Toggle Grid (Ctrl+G)", ToggleGrid); var gridBtn = (ToolStripButton)ts.Items[ts.Items.Count - 1]; gridBtn.Checked = true; var gridSizeItem = new ToolStripLabel(" Size: ") { ForeColor = Color.FromArgb(150, 150, 150), }; ts.Items.Add(gridSizeItem); var gridSizeBox = new NumericUpDown { Minimum = 0, Maximum = 40, Value = 8, Width = 45, BackColor = Color.FromArgb(55, 55, 55), ForeColor = Color.White, }; gridSizeBox.ValueChanged += (s, e) => { _canvas.GridSize = (int)gridSizeBox.Value; _canvas.Invalidate(); }; ts.Items.Add(new ToolStripControlHost(gridSizeBox)); AddButton("⬆ Front", "Bring to Front (Ctrl+B)", () => _canvas.BringToFrontSelected()); AddButton("⬇ Back", "Send to Back (Ctrl+Shift+B)", () => _canvas.SendToBackSelected(), separator: true); // Preview AddButton("▶ Preview", "Preview Form", PreviewForm, separator: true); // Export AddButton("📝 Export C#", "Export as C# code", ExportCSharp); AddButton("📝 Designer.cs", "Export Designer file", ExportDesigner, separator: true); // Help AddButton("❓ Help", "Keyboard shortcuts", ShowHelp); return ts; } private void SetupStatusbar() { _statusStrip = new StatusStrip { BackColor = Color.FromArgb(35, 35, 35), ForeColor = Color.White, SizingGrip = false, Font = new Font("Segoe UI", 8.5f), }; _statusLabel = new ToolStripStatusLabel { Text = "Ready", ForeColor = Color.FromArgb(200, 200, 200), Spring = true, TextAlign = ContentAlignment.MiddleLeft, }; _positionLabel = new ToolStripStatusLabel { Text = "X: 0, Y: 0", ForeColor = Color.FromArgb(150, 150, 150), BorderSides = ToolStripStatusLabelBorderSides.Left, BorderStyle = BorderStyle.None, Padding = new Padding(8, 0, 8, 0), }; _selectionLabel = new ToolStripStatusLabel { Text = "No selection", ForeColor = Color.FromArgb(150, 150, 150), BorderSides = ToolStripStatusLabelBorderSides.Left, Padding = new Padding(8, 0, 8, 0), }; _statusStrip.Items.Add(_statusLabel); _statusStrip.Items.Add(_positionLabel); _statusStrip.Items.Add(_selectionLabel); } // ========== EVENT HANDLERS ========== private void OnPaletteTypeSelected(string controlType) { _canvas.SetPendingControl(controlType); } private void OnSelectionChanged(DesignableControl? dc) { _propsPanel.ShowProperties(dc); _selectionLabel.Text = dc != null ? $"{dc.Name} ({dc.ControlType})" : "No selection"; } // ========== FILE OPERATIONS ========== private void NewProject() { if (_isDirty && MessageBox.Show( "Save current project?", "New Project", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes) { SaveProject(); } _canvas.ClearAll(); _currentFile = ""; _isDirty = false; UpdateTitle(); _statusLabel.Text = "New project created"; } private void OpenProject() { var file = ProjectManager.LoadProject(_canvas); if (file != null) { _currentFile = file; _isDirty = false; UpdateTitle(); _statusLabel.Text = $"Opened: {Path.GetFileName(file)}"; } } private void SaveProject() { if (string.IsNullOrEmpty(_currentFile)) { SaveProjectAs(); return; } SaveToFile(_currentFile); } private void SaveProjectAs() { var file = ProjectManager.SaveProject(_canvas); if (file != null) { _currentFile = file; _isDirty = false; UpdateTitle(); } } private void SaveToFile(string path) { try { var data = ProjectManager.CaptureState(_canvas, Path.GetFileNameWithoutExtension(path)); var json = System.Text.Json.JsonSerializer.Serialize( data, new System.Text.Json.JsonSerializerOptions { WriteIndented = true }); File.WriteAllText(path, json); _isDirty = false; UpdateTitle(); _statusLabel.Text = $"Saved: {Path.GetFileName(path)}"; } catch (Exception ex) { MessageBox.Show($"Save error: {ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } } private void UpdateTitle() { var name = string.IsNullOrEmpty(_currentFile) ? "Untitled" : Path.GetFileNameWithoutExtension(_currentFile); Text = $"WinForms Visual Designer - {name}{(_isDirty ? " *" : "")}"; } // ========== VIEW OPERATIONS ========== private void ToggleGrid() { _canvas.ShowGrid = !_canvas.ShowGrid; _canvas.Invalidate(); if (_toolStrip.Items.Count > 0) { // Find grid toggle button foreach (var item in _toolStrip.Items) { if (item is ToolStripButton btn && btn.Text.Contains("Grid")) { btn.Checked = _canvas.ShowGrid; break; } } } _statusLabel.Text = _canvas.ShowGrid ? "Grid visible" : "Grid hidden"; } // ========== PREVIEW ========== private void PreviewForm() { // Create a runtime form from the canvas contents var preview = new Form { Text = "Preview - Form1", Size = new Size(800, 600), StartPosition = FormStartPosition.CenterScreen, BackColor = _canvas.CanvasBackColor, }; // Clone all controls foreach (var dc in _canvas.DesignControls) { var original = dc.Control; var clone = CloneControl(original); if (clone != null) { clone.Enabled = true; clone.Visible = original.Visible; preview.Controls.Add(clone); } } // Add event handlers for interactive testing foreach (Control ctrl in preview.Controls) { if (ctrl is Button btn) { btn.Click += (s, e) => MessageBox.Show($"Button '{btn.Name}' clicked!", "Preview", MessageBoxButtons.OK, MessageBoxIcon.Information); } } preview.FormClosing += (s, e) => e.Cancel = false; preview.Show(this); _statusLabel.Text = "Preview opened"; } private Control? CloneControl(Control original) { try { var clone = Activator.CreateInstance(original.GetType()) as Control; if (clone == null) return null; clone.Bounds = original.Bounds; clone.BackColor = original.BackColor; clone.ForeColor = original.ForeColor; clone.Font = (Font)original.Font.Clone(); clone.Name = original.Name; clone.Visible = original.Visible; // Copy type-specific properties switch (original) { case Button b1 when clone is Button b2: b2.Text = b1.Text; b2.FlatStyle = b1.FlatStyle; break; case Label l1 when clone is Label l2: l2.Text = l1.Text; l2.TextAlign = l1.TextAlign; break; case TextBox t1 when clone is TextBox t2: t2.Text = t1.Text; t2.Multiline = t1.Multiline; t2.ReadOnly = t1.ReadOnly; break; case CheckBox c1 when clone is CheckBox c2: c2.Text = c1.Text; c2.Checked = c1.Checked; break; case RadioButton r1 when clone is RadioButton r2: r2.Text = r1.Text; r2.Checked = r1.Checked; break; case ComboBox cb1 when clone is ComboBox cb2: cb2.Items.AddRange(cb1.Items.Cast

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