Customizing the BitmapTool to create BitmapNode from the selected region instead of browsing the image location with the help of OpenDialogBox

2 mins read

In Diagram control, we can create the image node using bitmap tool but we don’t have a built-in option for selecting the particular region and create the image node based on selected region. However we can achieve the desired requirement by customizing the Syncfusion.Windows.Forms.Diagram.BitmapTool and by creating the Bitmapnode from the selected region instead of browsing the image location with the help of OpenDialogBox

Step1:

The following code example shows creating the custom bitmaptool and setting the name for customized bitmaptool while initializing.

[C#]

public class CustomSelectTool : BitmapTool
{
private string toolName = "CustomBitmapTool";
 
public CustomSelectTool(DiagramController controller)
: base(controller)
{
this.Name = toolName;
}
}

[VB]

Public Class CustomSelectTool
Inherits BitmapTool
Private toolName As String = "CustomBitmapTool"
 
Public Sub New(ByVal controller As DiagramController)
MyBase.New(controller)
Me.Name = toolName
End Sub
 
End Class

Step 2:

To override the CreateNode() method in customized bitmaptool to create the bitmapnode from the selected region

The following code example to create the bitmapnode from the selected region:

[C#]

protected override Node CreateNode(System.Drawing.RectangleF rectBounding)
{
//calculating the zoom factor
float scale = this.Controller.View.Magnification / 100;
 
Image img = new Bitmap((int)(Controller.Model.DocumentSize.Width), (int)(Controller.Model.DocumentSize.Height));
            
// exporting the diagram as image
img = (Controller.ParentControl as Diagram).ExportDiagramAsImage(true);
 
//convert model coordinates to client coordinate
PointF bounds = Controller.ConvertFromModelToClientCoordinates(rectBounding.Location);
            
//Crop the Selected region as image 
Bitmap croppedImage = (img as Bitmap).Clone(new System.Drawing.Rectangle((int)(bounds.X), (int)(bounds.Y ), (int)(rectBounding.Size.Width * scale), (int)(rectBounding.Size.Height * scale)), PixelFormat.Format64bppArgb);
 
//Creating the bitmap node from selected region
BitmapNode croppedNode = new BitmapNode(croppedImage, rectBounding);
 
img.Dispose();
croppedImage.Dispose();
            
return croppedNode;
 
}

[VB]

Protected Overrides Function CreateNode(ByVal rectBounding As System.Drawing.RectangleF) As Node
'calculating the zoom factor
Dim scale As Single = Me.Controller.View.Magnification / 100
 
Dim img As Image = New Bitmap(CInt(Fix(Controller.Model.DocumentSize.Width)), CInt(Fix(Controller.Model.DocumentSize.Height)))
 
' exporting the diagram as image
img = (TryCast(Controller.ParentControl, Diagram)).ExportDiagramAsImage(True)
 
'convert model coordinates to client coordinate
Dim bounds As PointF = Controller.ConvertFromModelToClientCoordinates(rectBounding.Location)
 
'Crop the Selected region as image 
Dim croppedImage As Bitmap = (TryCast(img, Bitmap)).Clone(New System.Drawing.Rectangle(CInt(Fix(bounds.X)), CInt(Fix(bounds.Y)), CInt(Fix(rectBounding.Size.Width * scale)), CInt(Fix(rectBounding.Size.Height * scale))), PixelFormat.Format64bppArgb)
 
'Creating the bitmap node from selected region
Dim croppedNode As New BitmapNode(croppedImage, rectBounding)
 
img.Dispose()
croppedImage.Dispose()
 
Return croppedNode
 
End Function

Sample:

Sample

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