| title | description | ms.date | helpviewer_keywords | ms.assetid | ||
|---|---|---|---|---|---|---|
Drag-and-Drop Functionality |
Learn about drag-and-drop functionality in Windows Forms, which includes a set of methods, events, and classes that implement drag-and-drop behavior. |
03/30/2017 |
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65cd2c03-8782-474e-b958-cbe43eeb902c |
Windows Forms includes a set of methods, events, and classes that implement drag-and-drop behavior. This topic provides an overview of the drag-and-drop support in Windows Forms. Also see Drag-and-Drop Operations and Clipboard Support.
To perform a drag-and-drop operation, use the xref:System.Windows.Forms.Control.DoDragDrop%2A method of the xref:System.Windows.Forms.Control class. For more information about how a drag-and-drop operation is performed, see xref:System.Windows.Forms.Control.DoDragDrop%2A. To get the rectangle that the mouse pointer must be dragged over before a drag-and-drop operation begins, use the xref:System.Windows.Forms.SystemInformation.DragSize%2A property of the xref:System.Windows.Forms.SystemInformation class.
There are two categories of events in a drag and drop operation: events that occur on the current target of the drag-and-drop operation, and events that occur on the source of the drag and drop operation.
The following table shows the events that occur on the current target of a drag-and-drop operation.
| Mouse Event | Description |
|---|---|
| xref:System.Windows.Forms.Control.DragEnter | This event occurs when an object is dragged into the control's bounds. The handler for this event receives an argument of type xref:System.Windows.Forms.DragEventArgs. |
| xref:System.Windows.Forms.Control.DragOver | This event occurs when an object is dragged while the mouse pointer is within the control's bounds. The handler for this event receives an argument of type xref:System.Windows.Forms.DragEventArgs. |
| xref:System.Windows.Forms.Control.DragDrop | This event occurs when a drag-and-drop operation is completed. The handler for this event receives an argument of type xref:System.Windows.Forms.DragEventArgs. |
| xref:System.Windows.Forms.Control.DragLeave | This event occurs when an object is dragged out of the control's bounds. The handler for this event receives an argument of type xref:System.EventArgs. |
The xref:System.Windows.Forms.DragEventArgs class provides the location of the mouse pointer, the current state of the mouse buttons and modifier keys of the keyboard, the data being dragged, and xref:System.Windows.Forms.DragDropEffects values that specify the operations allowed by the source of the drag event and the target drop effect for the operation.
The following table shows the events that occur on the source of the drag-and-drop operation.
| Mouse Event | Description |
|---|---|
| xref:System.Windows.Forms.Control.GiveFeedback | This event occurs during a drag operation. It provides an opportunity to give a visual cue to the user that the drag-and-drop operation is occurring, such as changing the mouse pointer. The handler for this event receives an argument of type xref:System.Windows.Forms.GiveFeedbackEventArgs. |
| xref:System.Windows.Forms.Control.QueryContinueDrag | This event is raised during a drag-and-drop operation and enables the drag source to determine whether the drag-and-drop operation should be canceled. The handler for this event receives an argument of type xref:System.Windows.Forms.QueryContinueDragEventArgs. |
The xref:System.Windows.Forms.QueryContinueDragEventArgs class provides the current state of the mouse buttons and modifier keys of the keyboard, a value specifying whether the ESC key was pressed, and a xref:System.Windows.Forms.DragAction value that can be set to specify whether the drag-and-drop operation should continue.