public const int WM_DEVICECHANGE = 0x219;是什么意思
public const int DBT_DEVICEARRIVAL = 0x8000;public const int DBT_CONFIGCHANGECANCELED = 0x0019;
public const int DBT_CONFIGCHANGED = 0x0018;
public const int DBT_CUSTOMEVENT = 0x8006;
public const int DBT_DEVICEQUERYREMOVE = 0x8001;
public const int DBT_DEVICEQUERYREMOVEFAILED = 0x8002;
public const int DBT_DEVICEREMOVECOMPLETE = 0x8004;
public const int DBT_DEVICEREMOVEPENDING = 0x8003;
public const int DBT_DEVICETYPESPECIFIC = 0x8005;
public const int DBT_DEVNODES_CHANGED = 0x0007;
public const int DBT_QUERYCHANGECONFIG = 0x0017;
public const int DBT_USERDEFINED = 0xFFFF;
又分别是什么意思?谢谢