IDropTarget (Compact 2013)
3/28/2014
This interface is used to allow drag-and-drop operations in an application. Its methods are used by any application that can be a target for drag-and-drop operations.
When to Implement
Implement this 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.
Methods
The following table shows the methods for this interface. Like all COM interfaces, this interface inherits the methods for the IUnknown interface.
Method |
Description |
|---|---|
Indicates whether a drop can be accepted, and, if so, the effect of the drop. |
|
Removes target feedback and releases the data object. |
|
Provides target feedback to the user and communicates the drop's effect to the DoDragDrop function so it can communicate the effect of the drop back to the source. |
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Incorporates the source data into the target window, removes target feedback, and releases the data object. |
Obtaining a Pointer
Do not call the methods of IDropTarget directly. See Remarks for more information.
Remarks
An application that can be a target for drag-and-drop operations is responsible for the following:
- Determining the effect of the drop on the target application.
- Incorporating any valid data when the drop occurs.
- Communicating target feedback to the source application so it 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 those tasks, you must call the RegisterDragDrop and the RevokeDragDrop functions.
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.
Requirements
Header |
shobjidl.h, |
Library |
Developer Implemented |