The EDITSTREAM structure contains information about a data stream used with a rich edit control.
typedef struct _editstream { DWORD dwCookie; DWORD dwError; EDITSTREAMCALLBACK pfnCallback; } EDITSTREAM;
This structure is used with the EM_STREAMIN message to read (stream in) data into a rich edit control, replacing its contents. It is used with the EM_STREAMOUT message to write (stream out) the contents of a rich edit control.
The control calls the callback function repeatedly, transferring a portion of the data with each call. The callback function has the following form:
DWORD CALLBACK EditStreamCallback(DWORD dwCookie, LPBYTE pbBuff, LONG cb, LONG FAR *pcb);
The return value is zero to continue to the stream operation, or nonzero to abort it.