Über alle USB Anschlüsse iterieren, um ein bestimmtes Gerät zu finden

[Aphton]

Sofern du es wirklich voll automatisch haben und nicht ständig pollen willst, dann schau dir mal WM_DEVICECHANGE an..

Delphi-Quellcode:

type
  TForm1 = class(TForm)
  public
    procedure DeviceChange(var Msg: TMessage); message WM_DEVICECHANGE;
  end;

// ......

const
  DBT_DEVICEARRIVAL = $8000;
  DBT_DEVTYP_VOLUME = $02;

type
  _DEV_BROADCAST_HDR = record
    dbch_size: DWORD;
    dbch_devicetype: DWORD;
    dbch_reserved: DWORD;
  end;
  PDevBroadcastHdr = ^TDevBroadcastHdr;
  TDevBroadcastHdr = _DEV_BROADCAST_HDR;

  _DEV_BROADCAST_VOLUME = record
    dbcv_size: DWORD;
    dbcv_devicetype: DWORD;
    dbcv_reserved: DWORD;
    dbcv_unitmask: DWORD;
    dbcv_flags: WORD;
  end;
  PDevBroadcastVolume = ^TDevBroadcastVolume;
  TDevBroadcastVolume = _DEV_BROADCAST_VOLUME;

function BitScanForward(Value: Integer): Integer;
asm
  bsf eax, eax
end;

procedure TForm1.DeviceChange(var Msg: TMessage);
var
  DriveLetter: Char;
begin
  case Msg.WParam of
    DBT_DEVICEARRIVAL:
      if PDevBroadcastHdr(Msg.LParam).dbch_devicetype = DBT_DEVTYP_VOLUME then
      begin
        DriveLetter := Char(65 + BitScanForward(PDevBroadcastVolume(Msg.LParam).dbcv_unitmask));
        ShowMessage('New device plugged in: ' + DriveLetter);
//        ShowMessage('DriveType: ' + IntToStr(GetDriveType(pChar(DriveLetter + ':'))));
      end;
  end;
end;