USB设备拔插无法识别

2万 · 2012-3-10 12:13

芯片是cypress的。希望各位能帮我分析一下问题可能出在什么地方？

1万 · 2012-3-10 12:15

如果可能的话，能否简要介绍一下系统检测USB设备的原理。谢谢

2万 · 2012-3-10 12:17

你在WM_DEVICECHANGE函数中枚举你的设备，如果能够枚举到就表明有你的设备插入了。

2万 · 2012-3-10 12:19

C/C++ code

LRESULT CALLBACK
WndProc( HWND hwnd,    // handle to window
               UINT uMsg,    // message identifier
               WPARAM wParam, // First message parameter
               LPARAM lParam) // second message parameter
{
if ( g_device == NULL )
      return 0;
DEV_BROADCAST_HDR * dhr;
switch ( uMsg )
{
case WM_TIMER:
      g_device->CheckChange();
break;
case WM_DEVICECHANGE:  //
      char str[256];
      dhr = (DEV_BROADCAST_HDR*)lParam;
      switch( wParam )
      {
      case DBT_DEVICEARRIVAL:
         PDEV_BROADCAST_DEVICEINTERFACE lpdbd;
         PDEV_BROADCAST_VOLUME lpdbv;
         switch( dhr->dbch_devicetype )
         {
         case DBT_DEVTYP_DEVICEINTERFACE:
            lpdbd = (PDEV_BROADCAST_DEVICEINTERFACE)lParam;
            sprintf( str, "GUID:%x-%x-%x-%x", lpdbd->dbcc_classguid.Data1, lpdbd->dbcc_classguid.Data2, lpdbd->dbcc_classguid.Data3, lpdbd->dbcc_classguid.Data4 );
         break;
         case DBT_DEVTYP_VOLUME:
            lpdbv = (PDEV_BROADCAST_VOLUME)lParam;
            char cDisk = FirstDriverFromMask(lpdbv->dbcv_unitmask);
            sprintf( str, "Drive: %c 盘插入", cDisk );
            if ( g_device->m_usb_IsDisab )
            {
                  GetUSBDiskID(cDisk);
            }
            g_device->CheckSet();
         break;
         }// end switch
      break;
      case DBT_DEVICEREMOVECOMPLETE:
         if ( dhr->dbch_devicetype == DBT_DEVTYP_VOLUME )
         {
            PDEV_BROADCAST_VOLUME lpdbv = (PDEV_BROADCAST_VOLUME)lParam;
            //sprintf( str, "Drive: %c 盘拔出", FirstDriverFromMask(lpdbv->dbcv_unitmask) );
            //g_device->CheckSet();
         }
      break;
      } // end switch( wParam )
break;
case WM_DESTROY:
      PostQuitMessage(0);
break;
} // end switch
return DefWindowProc( hwnd, uMsg, wParam, lParam );
}