Places the specified IDataObject instance on the clipboard making it accessible to the OleGetClipboard function.

HRESULT OleSetClipboard(

IDataObject * pDataObj
//The data object being copied or cut



Points to an IDataObject instance from which the data to be placed on the clipboard can be obtained. This parameter can be NULL; in which case the clipboard is emptied.

Return Values


Indicates the IDataObject interface was placed on the clipboard.


Indicates the Windows OpenClipboard function used within OleSetClipboard failed.


Indicates the Windows EmptyClipboard function used within OleSetClipboard failed.


Indicates the Windows CloseClipboard function used within OleSetClipboard failed.


If you are writing an application that can act as the source of a clipboard operation, you must:

  1. Create an instance of the IDataObject interface for the data being copied or cut to the clipboard. This IDataObject should be the same as the IDataObject used in OLE drag and drop operations.

  2. Call OleSetClipboard to place the IDataObject on the clipboard and make it accessible to the OleGetClipboard function. OleSetClipboard also calls the IUnknown::AddRef method on your data object.

  3. If you wish, release the IDataObject once you have placed it on the clipboard to free the IUnknown::AddRef counter in your application.

  4. If the user is cutting data to the clipboard, remove the data from the document.

All formats are offered on the clipboard using delayed rendering. The formats necessary for OLE 1 compatibility are synthesized from the OLE 2 formats that are present and are also put on the clipboard.

The OleSetClipboard function assigns ownership of the clipboard to an internal OLE window handle. The reference count of the data object is increased by 1. This is done so that delayed rendering can be used. The reference count is decreased by a call to the OleFlushClipboard function or by a subsequent call to OleSetClipboard using NULL.

The OleSetClipboard function empties the current clipboard before any new data is made available. When an application opens the clipboard (either directly or indirectly by calling the Windows OpenClipboard function), the clipboard cannot be used by any other application until it is closed. If the clipboard is currently open by another application, OleSetClipboard fails. The internal OLE window handle satisfies WM_RENDERFORMAT messages by delegating them to the instance of IDataObject that is on the clipboard.

Passing NULL for IDataObject is legal and it empties the clipboard. If the contents of the clipboard are the result of a previous OleSetClipboard call and the clipboard is released; the IDataObject that was passed to the previous call is released. The clipboard owner should use this as a signal that the data it previously offered is no longer on the clipboard.

If you need to leave the data on the clipboard after your application is closed, you can call OleFlushClipboard instead of OleSetClipboard using NULL.

See Also


Software for developers
Delphi Components
.Net Components
Software for Android Developers
More information resources
Unix Manual Pages
Delphi Examples