验证输出设备

打开 Sequencer 后，应检查 MIDI 映射器是否可用并选作输出设备。 以下示例使用 MCI_ STATUS 命令验证 MIDI 映射器是否为 MCI 排序器的输出设备。

UINT wDeviceID;      // valid MCI sequencer ID
DWORD dwReturn;
MCI_STATUS_PARMS mciStatusParms;

// Make sure the opened device is the MIDI mapper.

mciStatusParms.dwItem = MCI_SEQ_STATUS_PORT;

if (dwReturn = mciSendCommand(wDeviceID, MCI_STATUS, MCI_STATUS_ITEM,
    (DWORD)(LPVOID) &mciStatusParms))
{
    
    // Error sending MCI_STATUS command. 
    
    return;
}
if (LOWORD(mciStatusParms.dwReturn) == MIDI_MAPPER)
{
    
    // The MIDI mapper is the output device. 
    
}
Else
{
    
    // The MIDI mapper is not the output device. 
    
}