<b>用C++掌握DVD/CD驱动器的开关</b>[VC/C++编程]

在Windows资源浏览器中,可在DVD/CD光驱图标上单击鼠标右键,挑选"弹出"来翻开光驱仓门,你大概也发现了,菜单中并没有"关闭"号令来关闭光驱.下面,就让我们用程序来掌握翻开、关闭光驱.

程序的主要工作部份为CD_OpenClose(BOOL bOpen, TCHAR cDrive)函数:

//cDrive是光驱盘符,大概0x01为默许驱动器.
//比方:
//CD_OpenCloseDrive(TRUE, 'G'); //翻开光驱G:
//CD_OpenCloseDrive(FALSE, 'G'); //关闭光驱G:
//CD_OpenCloseDrive(TRUE, 1); //翻开第一个逻辑光驱
void CD_OpenCloseDrive(BOOL bOpenDrive, TCHAR cDrive)
{
　MCI_OPEN_PARMS op;
　MCI_STATUS_PARMS st;
　DWORD flags;
　TCHAR szDriveName[4];
　strcpy(szDriveName, "X:");
　::ZeroMemory(&op, sizeof(MCI_OPEN_PARMS));
　op.lpstrDeviceType = (LPCSTR) MCI_DEVTYPE_CD_AUDIO;
　if(cDrive > 1)
　{
　　szDriveName[0] = cDrive;
　　op.lpstrElementName = szDriveName;
　　flags = MCI_OPEN_TYPE | MCI_OPEN_TYPE_ID | MCI_OPEN_ELEMENT| MCI_OPEN_SHAREABLE;
　}
　else flags = MCI_OPEN_TYPE | MCI_OPEN_TYPE_ID | MCI_OPEN_SHAREABLE;
　if (!mciSendCommand(0,MCI_OPEN,flags,(unsigned long)&op))
　{
　　st.dwItem = MCI_STATUS_READY;
　　if(bOpenDrive)
　　　mciSendCommand(op.wDeviceID,MCI_SET,MCI_SET_DOOR_OPEN,0);
　　else
　　　mciSendCommand(op.wDeviceID,MCI_SET,MCI_SET_DOOR_CLOSED,0);
　　mciSendCommand(op.wDeviceID,MCI_CLOSE,MCI_WAIT,0);
　}
}
　　为了便利对多个光驱举行操作,增添了下面这个函数,其会调用上面的CD_OpenCloseDrive()函数:

void CD_OpenCloseAllDrives(BOOL bOpenDrives)
{
　//断定全部光驱,并一一翻开或关闭.
　int nPos = 0;
　UINT nCount = 0;
　TCHAR szDrive[4];
　strcpy(szDrive, "?:\");
　DWORD dwDriveList = ::GetLogicalDrives ();
　while (dwDriveList) {
　　if (dwDriveList & 1)
　　{
　　　szDrive[0] = 0x41 + nPos;
　　　if(::GetDriveType(szDrive) == DRIVE_CDROM)
　　　　CD_OpenCloseDrive(bOpenDrives, szDrive[0]);
　　}
　　dwDriveList >>= 1;
　　nPos++;
　}
}
　　最后一点,别忘了在程序开首包含Mmsystem.h头文件,及在链接选项里写上Winmm.lib.