Getting the classes of custom created shapes

2 posts, 0 answers
  1. Jacques
    Jacques avatar
    4 posts
    Member since:
    Jan 2019

    Posted 31 Jan 2019 Link to this post


    I have made classes for custom shapes that i have added to my toolbox. All these classes are derived from ElementShape. My problem however is that i would like to get the type of each shape as the way i created them with my own separate classes. Once these custom shapes are dragged from the toolbox and dropped onto the diagram, they are identified as RadDiagramShape. This is a problem because i need to identify of which type each shape is, as the way that i have declared them. For example i have declared a class with an Input shape, and a class with an Output shape. I need to know from the diagram, which shape is of what type, for example is it an input shape or is it an output shape. Because my current code only tells me that it is a RadDiagramShape. This does not allow me to know whether it is an input or an output. I have attached screenshot of the problem and of my code. 

    Thank you,

  2. Hristo
    Hristo avatar
    1519 posts

    Posted 31 Jan 2019 Link to this post

    Hi Jacques,

    When creating the custom toolbox it will be necessary to also override the CreateDiagramShape method and return a custom type inheriting the base RadDiagramShape class: 
    public class CustomDiagramToolBox : RadDiagramToolbox
        public CustomDiagramToolBox()
        protected override void CreateDataItems()
            ListViewDataItemGroup customGroup = new ListViewDataItemGroup("Custom Group");
            DiagramListViewDataItem item = new DiagramListViewDataItem() { Key = "CustomShape" };
            ElementShape shape = new CustomElementShape();
            item.Shape = shape;
            item.Group = customGroup;
        protected override RadDiagramShape CreateDiagramShape(PreviewDragStartEventArgs e)
            DiagramListViewVisualItem sourceItem = e.DragInstance as DiagramListViewVisualItem;
            DiagramListViewDataItem dataItem = sourceItem.Data as DiagramListViewDataItem;
            if (dataItem.Shape is CustomElementShape)
                return new CustomDiagramShape
                    Shape = dataItem.Shape,
                    Text = dataItem.Key.ToString()
            return base.CreateDiagramShape(e);
    public class CustomElementShape : ElementShape
        public override GraphicsPath CreatePath(System.Drawing.Rectangle bounds)
            GraphicsPath path = new GraphicsPath();
            path.AddLine(0, 0, bounds.Width, 0);
            path.AddLine(bounds.Width, 0, bounds.Width, bounds.Height - (bounds.Height * 0.5f));
            path.AddLine(bounds.Width, bounds.Height - (bounds.Height * 0.5f), bounds.Width / 2, bounds.Height);
            path.AddLine(bounds.Width / 2, bounds.Height, 0, bounds.Height - (bounds.Height * 0.5f));
            path.AddLine(0, bounds.Height - (bounds.Height * 0.5f), 0, 0);
            return path;
    public class CustomDiagramShape : RadDiagramShape
        public CustomDiagramShape()
            this.Size = new System.Drawing.Size(80, 60);
            this.BackColor = System.Drawing.Color.LightBlue;
            this.DrawBorder = true;

    Then in the form, you can iterate the Shapes collection and check for the particular custom types: 
    private void button1_Click(object sender, EventArgs e)
        foreach (Telerik.Windows.Diagrams.Core.IShape shape in this.radDiagram1.Shapes)
            if (shape.GetType().IsSubclassOf(typeof(RadDiagramShape)))

    I hope this will help. Let me know if you need further assistance.

    Progress Telerik
    Get quickly onboarded and successful with your Telerik and/or Kendo UI products with the Virtual Classroom free technical training, available to all active customers. Learn More.
Back to Top