How to copy string to clipboard in C?

unknown picture unknown · Aug 12, 2009 · Viewed 39.8k times · Source

The SetClipboardData function requires a HANDLE reference; I'm having trouble converting my string for use in the function.

Here is my code:

char* output = "Test";
HLOCAL hMem =  LocalAlloc( LHND,1024);
char* cptr = (char*) LocalLock(hMem);
memcpy( cptr, output, 500 );
SetClipboardData(CF_TEXT, hMem);
LocalUnlock( hMem );
LocalFree( hMem );
CloseClipboard();

What am I doing wrong here and what's the proper way to do it?

Thanks.

Answer

Judge Maygarden picture Judge Maygarden · Aug 12, 2009

Read the MSDN documentation for the SetClipboardData function. It appears you are missing a few steps and releasing the memory prematurely. First of all, you must call OpenClipboard before you can use SetClipboardData. Secondly, the system takes ownership of the memory passed to the clipboard and it must be unlocked. Also, the memory must be movable, which requires the GMEM_MOVEABLE flag as used with GlobalAlloc (instead of LocalAlloc).

const char* output = "Test";
const size_t len = strlen(output) + 1;
HGLOBAL hMem =  GlobalAlloc(GMEM_MOVEABLE, len);
memcpy(GlobalLock(hMem), output, len);
GlobalUnlock(hMem);
OpenClipboard(0);
EmptyClipboard();
SetClipboardData(CF_TEXT, hMem);
CloseClipboard();