C# 获取USB插拔消息,并得到U盘盘符

const int WM_DEVICECHANGE = 0x2190; const int DBT_DEVICEARRIVAL = 0x8000; const int DBT_DEVICEREMOVECOMPLETE = 0x8004; protected override void WndProc(ref Message m) { ManagementClass DiskClass = new ManagementClass(@"Win32_Diskdrive"); try { if (m.WParam.ToInt32() == DBT_DEVICEARRIVAL) { ManagementObjectCollection Moc =DiskClass.GetInstances(); } if (m.WParam.ToInt32() == DBT_DEVICEREMOVECOMPLETE) { ManagementObjectCollection Moc= DiskClass.GetInstances(); } } catch (Exception ex){}需要,监视USB插拔信息，然后获取USB的磁盘号,比如HD0，HD1这个磁盘号。 这样的话，会提示异常，异常如下：请问该怎么解决？谢谢了。我只有10积分，只能悬赏10分了不好意思