Platform SDK: Interprocess Communications

Multiple Clipboard Formats

A window can place more than one clipboard object on the clipboard, each representing the same information in a different clipboard format. When placing information on the clipboard, the window should provide data in as many formats as possible. To find out how many formats are currently used on the clipboard, call the CountClipboardFormats function.

Clipboard formats that contain the most information should be placed on the clipboard first, followed by less descriptive formats. A window pasting information from the clipboard typically retrieves a clipboard object in the first format it recognizes. Because clipboard formats are enumerated in the order they are placed on the clipboard, the first recognized format is also the most descriptive.

For example, suppose a user copies styled text from a word-processing document. The window containing the document might first place data on the clipboard in a registered format, such as RTF. Subsequently, the window would place data on the clipboard in a less descriptive format, such as text (CF_TEXT).

When the content of the clipboard is pasted into another window, the window retrieves data in the most descriptive format it recognizes. If the window recognizes RTF, the corresponding data is pasted into the document. Otherwise, the text data is pasted into the document and the formatting information is lost.