CancelDC

The CancelDC function cancels any pending operation on the specified device context (DC).

BOOL CancelDC(
  HDC hdc   // handle to device context
);
 

Parameters

hdc

Handle to the DC.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero.

Windows NT: To get extended error information, call GetLastError.

Remarks

The CancelDC function is used by multithreaded applications to cancel lengthy drawing operations. If thread A initiates a lengthy drawing operation, thread B may cancel that operation by calling this function.

If an operation is canceled, the affected thread returns an error and the result of its drawing operation is undefined. The results are also undefined if no drawing operation was in progress when the function was called.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Unsupported.
  Windows CE: Unsupported.
  Header: Declared in wingdi.h.
  Import Library: Use gdi32.lib.

See Also

Device Contexts Overview, Device Context Functions, CreateThread, GetCurrentThread