IDirectMusicPort8::DeviceIoControl
The DeviceIoControl method calls the Win32 DeviceIoControl function on the underlying file handle implementing the port.
Syntax
HRESULT DeviceIoControl(
DWORD dwIoControlCode,
LPVOID lpInBuffer,
DWORD nInBufferSize,
LPVOID lpOutBuffer,
DWORD nOutBufferSize,
LPDWORD lpBytesReturned,
LPOVERLAPPED lpOverlapped
);
Parameters
dwIoControlCode
Control code of the operation to perform.
lpInBuffer
Buffer that contains input data.
nInBufferSize
Size of input buffer.
lpOutBuffer
Buffer that receives output data.
nOutBufferSize
Size of the output buffer.
lpBytesReturned
Address of a variable that receives the output byte count.
lpOverlapped
Address of an OVERLAPPED structure for asynchronous operation. OVERLAPPED is defined in Winbase.h.
Return Values
If the method succeeds, the return value is S_OK.
If it fails, the method can return one of the error values shown in the following table.
| Return code |
| E_POINTER |
| E_NOTIMPL |
Remarks
This method is supported only on ports implemented by a Windows Driver Model (WDM) filter graph. In the case of a WDM filter graph, the file handle used is the topmost pin in the graph.
DirectMusic can refuse to perform defined kernel streaming operations on a pin that might collide with operations that it is performing on the filter graph. User-defined operations, however, are never blocked.
Requirements
** Header:** Dmusicc.h
See Also