IDropTarget

The IDropTarget interface is one of the interfaces you implement to provide drag-and-drop operations in your application. It contains methods used in any application that can be a target for data during a drag-and-drop operation. A drop-target application is responsible for:

• Determining the effect of the drop on the target application.
• Incorporating any valid dropped data when the drop occurs.
• Communicating target feedback to the source so the source application can provide appropriate visual feedback such as setting the cursor.
• Implementing drag scrolling.
• Registering and revoking its application windows as drop targets.

The IDropTarget interface contains methods that handle all these responsibilities except registering and revoking the application window as a drop target, for which you must call the RegisterDragDrop and the RevokeDragDrop functions.

When to Implement

Implement the IDropTarget interface if you are developing an application that can act as a target for a drag-and-drop operation. The IDropTarget interface is associated with your application windows and is implemented on your window objects. Call the RegisterDragDrop function to register your window objects as drop targets.

When to Use

You do not call the methods of IDropTarget directly. The DoDragDrop function calls the IDropTarget methods during the drag-and-drop operation.

For example, DoDragDrop calls IDropTarget::DragEnter when it detects the mouse has moved over a window that is registered as a drag target. Once the mouse has entered a drag-target window, DoDragDrop calls IDropTarget::DragOver as the mouse moves through the window and calls IDropTarget::DragLeave if the mouse leaves the target window or if the user cancels or completes the drag-and-drop operation. DoDragDrop calls IDropTarget::Drop if the drop finally occurs.

Methods in Vtable Order

QuickInfo

  Windows NT: Use version 3.1 or later.
  Windows: Use Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in oleidl.h.

See Also

DoDragDrop, IDropSource, RegisterDragDrop, RevokeDragDrop