编程光驱监测

 

光驱监测

用VC6新建一个Dialog对话框类的程序，重载WindowProc()函数（在“查看”à“新建类向导”页面“Messages”中找到主对话框的WindowProc()虚汗数，点击右边创建并编辑它），参照下面内容添加进入即可。下面是源码，要说的都包含在注释中了，看看吧：

 

LRESULT CTestDlg::WindowProc(UINT message, WPARAM wParam, LPARAM lParam)

{

    // TODO: Add your specialized code here and/or call the base class

    PDEV_BROADCAST_HDR lpdb = (PDEV_BROADCAST_HDR)lParam;

    CString szMsg;

    if(message == WM_DEVICECHANGE)

    {

         switch(wParam)

         {

             //当一个设备变得被插入并变得可用时，

             //系统会发送广播事件DBT_DEVICEARRIVAL

         case DBT_DEVICEARRIVAL:

             // 判断CDROM碟片是否已经插入到光驱中

             if (lpdb -> dbch_devicetype == DBT_DEVTYP_VOLUME)

             {

                  PDEV_BROADCAST_VOLUME lpdbv=(PDEV_BROADCAST_VOLUME) lpdb;

                  //判断是否有CDROM碟片

                  if (lpdbv -> dbcv_flags & DBTF_MEDIA)

                  {

                      // 显示消息，获取光驱的逻辑驱动器号

                      szMsg.Format("驱动器%c: 已经可用/n",chFirstDriveFromMask(lpdbv ->dbcv_unitmask));

                      AfxMessageBox(szMsg);

                  }

             }

             break;

        

             //当一个设备变得被移走并变得不可用时，

             //系统会发送广播事件DBT_ DEVICEREMOVECOMPLETE

         case DBT_DEVICEREMOVECOMPLETE:

                  // 判断CDROM碟片是否从光驱中移走

                  if (lpdb -> dbch_devicetype == DBT_DEVTYP_VOLUME)

                  {

                      PDEV_BROADCAST_VOLUME lpdbv = (PDEV_BROADCAST_VOLUME)lpdb;

                      if (lpdbv -> dbcv_flags & DBTF_MEDIA)

                      {

                          //显示消息，获取光驱的逻辑驱动器号

                          szMsg.Format("驱动器%c: 已经弹出/n",chFirstDriveFromMask(lpdbv ->dbcv_unitmask));

                          AfxMessageBox(szMsg);

                      }

                  }

                  break;

             }

    }

    return CDialog::WindowProc(message, wParam, lParam);

}

 

其中用到的函数chFirstDriveFromMask()如下：

char chFirstDriveFromMask (ULONG unitmask)

{

    char i;

    for (i = 0; i < 26; ++i) //假设不会超过个逻辑驱动器

    {

         if (unitmask & 0x1) //看该驱动器的状态是否发生了变化

         break;

         unitmask = unitmask >> 1;

    }

    return (i + 'A');

}