DragDrop.DoDragDrop Method (DependencyObject, Object, DragDropEffects)


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Initiates a drag-and-drop operation.

Namespace:   System.Windows
Assembly:  PresentationCore (in PresentationCore.dll)

public static DragDropEffects DoDragDrop(
	DependencyObject dragSource,
	object data,
	DragDropEffects allowedEffects


Type: System.Windows.DependencyObject

A reference to the dependency object that is the source of the data being dragged.

Type: System.Object

A data object that contains the data being dragged.

Type: System.Windows.DragDropEffects

One of the DragDropEffects values that specifies permitted effects of the drag-and-drop operation.

Return Value

Type: System.Windows.DragDropEffects

One of the DragDropEffects values that specifies the final effect that was performed during the drag-and-drop operation.

Exception Condition

dragSource or data is null.

It is the responsibility of your application to determine when a drag occurs, and then initiate the drag-and-drop operation. Typically, this is when a MouseDown and MouseMove sequence of events occurs over the element to be dragged. You initiate the drag-and-drop operation by calling the static DoDragDrop method and passing the transferred data to it. The DoDragDrop method will automatically wrap the data in a DataObject if necessary. For greater control over the data format, you can wrap the data in a DataObject before passing it to the DoDragDrop method.

The value returned from the DoDragDrop method is the value of the DragEventArgs.Effects property set in the drop target’s Drop event handler. If the return value does not match one of the allowedEffects specified in the call to DoDragDrop, the drag-and-drop operation is not performed.

The following example shows how to initiate a drag-and-drop operation from the MouseMove event handler of an Ellipse element to make it a drag source. The transferred data is the string representation of the ellipse’s Fill property. The data is passed to the DoDragDrop method as a string and is automatically wrapped in a DataObject.

private void ellipse_MouseMove(object sender, MouseEventArgs e)
    Ellipse ellipse = sender as Ellipse;
    if (ellipse != null && e.LeftButton == MouseButtonState.Pressed)
        DragDrop.DoDragDrop( ellipse,

.NET Framework
Available since 3.0
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