Handling MCI Errors

You should always check the return value of the mciSendCommand function. If it indicates an error, you can use mciGetErrorString to get a textual description of the error.

The following example passes the MCI error code specified by dwError to mciGetErrorString, and then displays the resulting textual error description using the MessageBox function.

// Use mciGetErrorString to get a textual description of an MCI error.
// Display the error description using MessageBox.

void showError(DWORD dwError)
{
    char szErrorBuf[MAXERRORLENGTH];
    MessageBeep(MB_ICONEXCLAMATION);
    if(mciGetErrorString(dwError, (LPSTR) szErrorBuf, MAXERRORLENGTH))
    {
        MessageBox(hMainWnd, szErrorBuf, "MCI Error",
        MB_ICONEXCLAMATION);
    }
    else
    {
        MessageBox(hMainWnd, "Unknown Error", "MCI Error",
            MB_ICONEXCLAMATION);
    }
}
 

• Note   To interpret an mciSendCommand error return value yourself, mask the high-order word (the low-order word contains the error code). If you pass the error return value to mciGetErrorString, however, you must pass the entire doubleword value.