How To Create a Custom Symbol

16 Dec 20245 minutes to read

The following code sample demonstrates how you can create a custom symbol and use it in Essential® Diagram.

1. Create the custom symbol.

        // Custom Symbol (MySymbol.cs)
   
        public class MySymbol : Symbol
   
        {
   
            private Syncfusion.Windows.Forms.Diagram.Rectangle outerRect = null;
   
            private Ellipse innerEllipse = null;
   
   
   
            public MySymbol()
   
            {
   
               // Add child nodes to the symbol programmatically.
   
               // Add an outer rectangle.
   
                this.outerRect = new Syncfusion.Windows.Forms.Diagram.Rectangle(0, 0, 120, 80);
   
                this.outerRect.Name = "Rectangle";
   
                this.outerRect.FillStyle.Color = Color.Khaki;
   
                this.AppendChild(outerRect);
   
   
   
                // Add an inner ellipse.
   
                this.innerEllipse = new Ellipse(10, 10, 100, 60);
   
                this.innerEllipse.Name = "Ellipse";
   
                this.AppendChild(innerEllipse);
   
   
   
                // Add Label.
   
                Label lbl = this.AddLabel("My Symbol", BoxPosition.Center);
   
                lbl.BackgroundStyle.Color = Color.Transparent;
   
            }
   
        }

        ' Custom Symbol (MySymbol.vb)
   
        Public Class MySymbol
   
                Inherits Symbol
   
                Private outerRect As Syncfusion.Windows.Forms.Diagram.Rectangle = Nothing
   
                Private innerEllipse As Syncfusion.Windows.Forms.Diagram.Ellipse = Nothing
   
   
   
                Public Sub New()
   
   
   
                    ' Add child nodes to the symbol programmatically.
   
   
   
                    ' Add an outer rectangle.
   
                    Me.outerRect = New Syncfusion.Windows.Forms.Diagram.Rectangle(0, 0, 120, 80)
   
                    Me.outerRect.Name = "Rectangle"
   
                    Me.outerRect.FillStyle.Color = Color.Khaki
   
                    Me.AppendChild(outerRect)
   
   
   
                    ' Add an inner ellipse.
   
                    Me.innerEllipse = New Syncfusion.Windows.Forms.Diagram.Ellipse(10, 10, 100, 60)
   
                    Me.innerEllipse.Name = "Ellipse"
   
                    Me.AppendChild(innerEllipse)
   
   
   
                    ' Add Label.
   
                    Dim lbl As Label = Me.AddLabel("My Symbol", BoxPosition.Center)
   
                    lbl.BackgroundStyle.Color = Color.Transparent
   
                End Sub ' New
   
        End Class ' MySymbol

2. Use the symbol in the form.

        // Register InsertTool for MySymbol.
   
        this.diagram1.Controller.RegisterTool(new InsertSymbolTool("InsertMySymbol", typeof(MySymbol)));
   
   
   
        // Activate InsertTool for MySymbol.
   
        this.diagram1.ActivateTool("InsertMySymbol");

        ' Register InsertTool for MySymbol.
   
        Me.diagram1.Controller.RegisterTool(New InsertSymbolTool("InsertMySymbol", GetType(MySymbol)))
   
   
   
        ' Activate InsertTool for MySymbol.
   
        Me.diagram1.ActivateTool("InsertMySymbol")