Drag Limit in WPF Diagram (SfDiagram)

21 Sep 20232 minutes to read

The drag limit allows you to define the dragging region of the Diagram while diagram objects are getting dragged. The DragLimit property of scroll settings class helps to limit the dragging area. It includes the following options:

Infinity: Allows you to drag the diagram objects in all directions without any restriction.
Diagram: Allows you to drag the diagram objects within the Diagram content.
Limited: Allows you to drag the diagram objects within the specified area. The EditableArea property is used to specify the area that is allowed to dragging.

The default operation is Infinity.

Drag limit behaviour will be enabled by handling the SelectorChangedEvent and its arguments of SelectorChangedEventArgs class of diagram control.

XAML
C#
<!--Initialize the Sfdiagram-->
<syncfusion:SfDiagram x:Name="diagram">
    <!--Initialize the scroll setting class with drag limit value-->
    <syncfusion:SfDiagram.ScrollSettings>
        <syncfusion:ScrollSettings DragLimit="Limited" EditableArea="100,100,400,300"/>
    </syncfusion:SfDiagram.ScrollSettings>
</syncfusion:SfDiagram>
//Initialize the SfDiagram
SfDiagram diagram = new SfDiagram();
//Register the selector changed event to handle it
(diagram.Info as IGraphInfo).SelectorChangedEvent += Diagram_SelectorChangedEvent;
//Initialize the scroll settings with drag limit and drag limit area
diagram.ScrollSettings = new ScrollSettings()
{
    DragLimit = ScrollLimit.Limited,
    EditableArea = new Rect(100, 100, 400, 300),
};

//Selector changed event
private void Diagram_SelectorChangedEvent(object sender, SelectorChangedEventArgs args)
{
    //Changing the cursor to indicate the dragging restriction 
    args.BlockCursor = Cursors.No;
    //Enabling the dragging limit
    args.Block = true;
}

DragLimit	Output
Infinity
Diagram
Limited EditableArea = (100, 100, 400, 300)

Drag Limit in WPF Diagram (SfDiagram)

See Also