unit USBDeviceNotify;
//USB Device arrival
or remove
interface
uses
Windows, Messages, SysUtils, Classes, Forms;
type
PDevBroadcastHdr =
^DEV_BROADCAST_HDR;
DEV_BROADCAST_HDR =
packed record
dbch_size: DWORD;
dbch_devicetype: DWORD;
dbch_reserved: DWORD;
end;
PDevBroadcastDeviceInterface =
^DEV_BROADCAST_DEVICEINTERFACE;
DEV_BROADCAST_DEVICEINTERFACE =
record
dbcc_size: DWORD;
dbcc_devicetype: DWORD;
dbcc_reserved: DWORD;
dbcc_classguid: TGUID;
dbcc_name: short;
end;
const
GUID_DEVINTERFACE_USB_DEVICE: TGUID =
'{A5DCBF10-6530-11D2-901F-00C04FB951ED}';
DBT_DEVICEARRIVAL = $
8000; //
system detected a new device
DBT_DEVICEREMOVECOMPLETE = $
8004; // device
is gone
DBT_DEVTYP_DEVICEINTERFACE = $
00000005; // device
interface class
type
TUSBDeviceEvent =
procedure(Sender: TObject; pDeviceData: PDevBroadcastDeviceInterface)
of object;
TUSBDeviceNotify =
class(TComponent)
private
FWindowHandle: HWND;
FOnUSBArrival: TUSBDeviceEvent;
FOnUSBRemove: TUSBDeviceEvent;
procedure WndProc(
var Msg: TMessage);
function USBRegister: Boolean;
protected
procedure WMDeviceChange(
var Msg: TMessage);
dynamic;
public
constructor Create(AOwner: TComponent);
override;
destructor Destroy;
override;
published
property OnUSBArrival: TUSBDeviceEvent
read FOnUSBArrival
write FOnUSBArrival;
property OnUSBRemove: TUSBDeviceEvent
read FOnUSBRemove
write FOnUSBRemove;
end;
implementation
constructor TUSBDeviceNotify.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FWindowHandle :=
AllocateHWnd(WndProc);
USBRegister;
end;
destructor TUSBDeviceNotify.Destroy;
begin
DeallocateHWnd(FWindowHandle);
inherited Destroy;
end;
procedure TUSBDeviceNotify.WndProc(
var Msg: TMessage);
begin
if (Msg.Msg = WM_DEVICECHANGE)
then
begin
try
WMDeviceChange(Msg);
except
Application.HandleException(Self);
end;
end
else
Msg.Result :=
DefWindowProc(FWindowHandle, Msg.Msg, Msg.wParam, Msg.lParam);
end;
procedure TUSBDeviceNotify.WMDeviceChange(
var Msg: TMessage);
var
devType: Integer;
Datos: PDevBroadcastHdr;
pData: PDevBroadcastDeviceInterface;
begin
if (Msg.wParam = DBT_DEVICEARRIVAL)
or (Msg.wParam = DBT_DEVICEREMOVECOMPLETE)
then
begin
Datos :=
PDevBroadcastHdr(Msg.lParam);
devType :=
Datos^.dbch_devicetype;
if devType = DBT_DEVTYP_DEVICEINTERFACE
then
begin //
USB Device
pData :=
PDevBroadcastDeviceInterface(Msg.LParam);
if Msg.wParam = DBT_DEVICEARRIVAL
then
begin
if Assigned(FOnUSBArrival)
then
FOnUSBArrival(Self, pData);
end
else
begin
if Assigned(FOnUSBRemove)
then
FOnUSBRemove(Self, pData);
end;
end;
end;
end;
function TUSBDeviceNotify.USBRegister: Boolean;
var
dbi: DEV_BROADCAST_DEVICEINTERFACE;
Size: Integer;
r: Pointer;
begin
Result :=
False;
Size :=
SizeOf(DEV_BROADCAST_DEVICEINTERFACE);
ZeroMemory(@dbi, Size);
dbi.dbcc_size :=
Size;
dbi.dbcc_devicetype :=
DBT_DEVTYP_DEVICEINTERFACE;
dbi.dbcc_reserved :=
0;
dbi.dbcc_classguid :=
GUID_DEVINTERFACE_USB_DEVICE;
dbi.dbcc_name :=
0;
r :=
RegisterDeviceNotification(FWindowHandle, @dbi,
DEVICE_NOTIFY_WINDOW_HANDLE
);
if Assigned(r)
then
Result :=
True;
end;
end.
转载于:https://www.cnblogs.com/shangdawei/archive/2013/04/28/3049784.html
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