IDragSourceHelper interface (shobjidl_core.h)
Exposed by the Shell to allow an application to specify the image that will be displayed during a Shell drag-and-drop operation.
The IDragSourceHelper interface inherits from the IUnknown interface. IDragSourceHelper also has these types of members:
The IDragSourceHelper interface has these methods.
Initializes the drag-image manager for a windowless control.
Initializes the drag-image manager for a control with a window.
This interface is exposed by the Shell's drag-image manager. It is not implemented by applications.
Use this interface to specify the image displayed during a Shell drag-and-drop operation. The IDragSourceHelper, IDropTargetHelper, and IInitializeWithWindow interfaces are exposed by the drag-image manager object to allow the IDropTarget interface to use custom drag images. To use either of these interfaces, you must create an in-process server drag-image manager object by calling CoCreateInstance with a class identifier (CLSID) of CLSID_DragDropHelper. Get interface pointers using standard Component Object Model (COM) procedures.
The IDragSourceHelper interface provides the following two ways to specify the bitmap to be used as a drag image.
- Controls that have a window can register a DI_GETDRAGIMAGE window message for it and initialize the drag-image manager with IDragSourceHelper::InitializeFromWindow. When the DI_GETDRAGIMAGE message is received, the handler puts the drag image bitmap information in the SHDRAGIMAGE structure that is passed as the message's lParam value.
- Windowless controls can initialize the drag-image manager with IDragSourceHelper::InitializeFromBitmap. This method allows an application to simply specify the bitmap.
|Minimum supported client||Windows 2000 Professional, Windows XP [desktop apps only]|
|Minimum supported server||Windows Server 2003 [desktop apps only]|
|Header||shobjidl_core.h (include Shobjidl.h)|