Detect USB Device Insert and Removal - uUsb by testest

unit uUsb;

//Author: testest

interface

uses Windows, Messages, Classes;

type

  PDevBroadcastHdr  = ^DEV_BROADCAST_HDR;

  DEV_BROADCAST_HDR = packed record

    dbch_size: DWORD;

    dbch_devicetype: DWORD;

    dbch_reserved: DWORD;

  end;

  TDevBroadcastHdr = DEV_BROADCAST_HDR;

type

  PDevBroadcastDeviceInterface  = ^DEV_BROADCAST_DEVICEINTERFACE;

  DEV_BROADCAST_DEVICEINTERFACE = record

    dbcc_size: DWORD;

    dbcc_devicetype: DWORD;

    dbcc_reserved: DWORD;

    dbcc_classguid: TGUID;

    dbcc_name: Char;

  end;

  TDevBroadcastDeviceInterface = DEV_BROADCAST_DEVICEINTERFACE;

const

  GUID_DEVINTERFACE_USB_DEVICE: TGUID = '{A5DCBF10-6530-11D2-901F-00C04FB951ED}';

  DBT_DEVICEARRIVAL          = $8000;

  DBT_DEVICEREMOVECOMPLETE   = $8004;

  DBT_DEVTYP_DEVICEINTERFACE = $00000005;

type

  TUsbNotifyProc = procedure(Sender: TObject; const DeviceName: String) of Object;

  TUsbNotifier = class

  private

    FWindowHandle: HWND;

    FNotificationHandle: Pointer;

    FOnUsbArrival: TUsbNotifyProc;

    FOnUsbRemoval: TUsbNotifyProc;

    procedure WndProc(var Msg: TMessage);

  public

    constructor Create;

    property OnUsbArrival: TUsbNotifyProc read FOnUsbArrival write FOnUsbArrival;

    property OnUsbRemoval: TUsbNotifyProc read FOnUsbRemoval write FOnUsbRemoval;

    destructor Destroy; override;

  end;

implementation

constructor TUsbNotifier.Create;

var

  Size: Cardinal;

  Dbi: TDevBroadcastDeviceInterface;

begin

  inherited;

  FWindowHandle := AllocateHWnd(WndProc);

  Size := SizeOf(Dbi);

  ZeroMemory(@Dbi, Size);

  Dbi.dbcc_size := Size;

  Dbi.dbcc_devicetype := DBT_DEVTYP_DEVICEINTERFACE;

  Dbi.dbcc_classguid := GUID_DEVINTERFACE_USB_DEVICE;

  FNotificationHandle := RegisterDeviceNotification(FWindowHandle, @Dbi,

                                              DEVICE_NOTIFY_WINDOW_HANDLE);

end;

procedure TUsbNotifier.WndProc(var Msg: TMessage);

var

  Dbi: PDevBroadcastDeviceInterface;

begin

  with Msg do

  if (Msg = WM_DEVICECHANGE)

      and ((WParam = DBT_DEVICEARRIVAL)

        or (WParam = DBT_DEVICEREMOVECOMPLETE)) then

  try

    Dbi := PDevBroadcastDeviceInterface(LParam);

    if Dbi.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE then

    begin

      if WParam = DBT_DEVICEARRIVAL then

      begin

        if Assigned(FOnUsbArrival) then

          FOnUsbArrival(Self, PChar(@Dbi.dbcc_name));

      end

      else

      begin

        if Assigned(FOnUsbRemoval) then

          FOnUsbRemoval(Self, PChar(@Dbi.dbcc_name));

      end;

    end;

  except

    Result := DefWindowProc(FWindowHandle, Msg, WParam, LParam);

  end

  else

    Result := DefWindowProc(FWindowHandle, Msg, WParam, LParam);

end;

destructor TUsbNotifier.Destroy;

begin

  UnregisterDeviceNotification(FNotificationHandle);

  DeallocateHWnd(FWindowHandle);

  inherited;

end;

end.