INF: The Clipboard and the WM_RENDERFORMAT Message

ID Number: Q31668

2.x 3.00

WINDOWS

Summary:

The clipboard sends a WM_RENDERFORMAT message to an application to

request that application format the data last copied to the clipboard

in the specified format, and then pass a handle to the formatted data

to the clipboard.

If an application cannot supply the requested data, it should return a

NULL handle. Because most applications provide access to the actual

data (not rendered) through the CF_TEXT format, applications that use

the clipboard can get the applicable data when rendering fails.

If the application cannot render the data because the system is out of

memory, the application can call GlobalCompact(-1) to discard and

compress memory, then try the memory allocation request again.

If this fails to provide enough memory, the application can render the

data into a file. However, applications that use this technique must

cooperate in order to know that the information is in a file, the name

of the file, and the format of the data.