检测何时使用 Delphi 在 Windows 中安装卷
Detecting when a volume is mounted in Windows with Delphi
我正在尝试了解 MSDN 上有关设备事件的文档
以及如何在安装卷时触发通知。
我已使用以下 post 中提供的信息为 USB 设备执行此操作：detect usb drive/device using delphi
以及在互联网上找到的其他信息，
但我注意到直接挂载卷会更容易检测到。
所以我的问题是：如何在我的 Delphi 应用程序中实现设备事件处理？
我正在查看以下文档：https://msdn.microsoft.com/en-us/library/windows/desktop/aa363217(v=vs.85).aspx
但我真的不知道怎么弄，运行。
到目前为止，我已经尝试了以下代码，它编译正确，
但什么也没发生，请把我推向正确的方向：
PDevBroadcastHdr = ^DEV_BROADCAST_HDR;
DEV_BROADCAST_HDR = packed record
dbch_size : DWORD;
dbch_devicetype : DWORD;
dbch_reserved : DWORD;
end;
PDevBroadcastHandle = ^DEV_BROADCAST_HANDLE;
DEV_BROADCAST_HANDLE = packed record
dbch_size : DWORD ;
dbch_devicetype : DWORD ;
dbch_reserved : DWORD ;
dbch_handle : THandle ;
dbch_hdevnotify : HDEVNOTIFY ;
dbch_eventguid : TGUID ;
dbch_nameoffset : LongInt ;
dbch_data : byte ;
end;
...
procedure WMDeviceChange(var Msg: TMessage);
const
DBT_DEVTYP_HANDLE = [=12=]06;
GUID_IO_VOLUME_MOUNT: TGUID = '{B5804878-1A96-11D2-8FFD-00A0C9A06D32}';
...
function TForm1.RegisterThis: Boolean;
var
dbv: DEV_BROADCAST_HANDLE;
Size: Integer;
r: Pointer;
begin
Size := SizeOf(DEV_BROADCAST_HANDLE);
ZeroMemory(@dbv, Size);
dbv.dbch_size := Size;
dbv.dbch_devicetype := DBT_DEVTYP_HANDLE;
dbv.dbch_reserved := 0;
dbv.dbch_handle := 0;
dbv.dbch_hdevnotify := nil;
dbv.dbch_eventguid := GUID_IO_VOLUME_MOUNT;
dbv.dbch_nameoffset := 0;
dbv.dbch_data := 0;
r := RegisterDeviceNotification(FWindowHandle, @dbv, DEVICE_NOTIFY_WINDOW_HANDLE);
if Assigned(r) then Result := True;
end;
procedure TForm1.WMDeviceChange(var Msg: TMessage);
var
VData: PDevBroadcastHandle;
begin
ShowMessage('Hello!');
end;
您必须像这样声明您的 WMDeviceChange 方法才能接收消息：
procedure WMDeviceChange(var Msg: TMessage); message WM_DEVICECHANGE;
此外，由于您的 WMDeviceChange 方法是表单的一部分，您应该使用表单 window Handle 来注册消息。
r := RegisterDeviceNotification(Handle, @dbv, DEVICE_NOTIFY_WINDOW_HANDLE);
由于 Handle 可以在 Form 的生命周期内重新创建，因此您应该覆盖 Form 的 CreateWnd 方法并在那里添加注册。
或者更好的是，您可以将功能封装在另一个 class:
TDeviceDetector = class
protected
fHandle: THandle;
procedure WndProc(var Message: TMessage);
public
constructor Create;
destructor Destroy; override;
function RegisterThis: Boolean;
end;
constructor TDeviceDetector.Create;
begin
inherited;
fHandle := AllocateHWnd(WndProc);
end;
destructor TDeviceDetector.Destroy;
begin
DeallocateHWnd(fHandle);
inherited;
end;
function TDeviceDetector.RegisterThis: Boolean;
var
dbv: DEV_BROADCAST_HANDLE;
Size: Integer;
r: Pointer;
begin
Size := SizeOf(DEV_BROADCAST_HANDLE);
ZeroMemory(@dbv, Size);
dbv.dbch_size := Size;
dbv.dbch_devicetype := DBT_DEVTYP_HANDLE;
dbv.dbch_reserved := 0;
dbv.dbch_handle := 0;
dbv.dbch_hdevnotify := nil;
dbv.dbch_eventguid := GUID_IO_VOLUME_MOUNT;
dbv.dbch_nameoffset := 0;
dbv.dbch_data := 0;
r := RegisterDeviceNotification(fHandle, @dbv, DEVICE_NOTIFY_WINDOW_HANDLE);
if Assigned(r) then Result := True;
end;
procedure TDeviceDetector.WndProc(var Message: TMessage);
begin
if Message.Msg = WM_DEVICECHANGE then
begin
ShowMessage('Hello!');
end
else Message.Result := DefWindowProc(FHandle, Message.Msg, Message.wParam, Message.lParam); // Default Message Handler
end;
到目前为止，你的问题还挺多的。这是我能看到的。
收件人不正确
您正在将 window 句柄传递给 RegisterDeviceNotification。但是，您的 window 句柄是否实现了 WM_DEVICECHANGE 的消息处理程序还远未明确。我建议使用 AllocateHWnd 获取 window 句柄，并在您提供给 AllocateHWnd.
的 window 过程中处理 WM_DEVICECHANGE
调用UnregisterDeviceNotification失败
RegisterDeviceNotification 的文档说：
Device notification handles returned by RegisterDeviceNotification must be closed by calling the UnregisterDeviceNotification function when they are no longer needed.
你没有做到这一点。当您不想再收到通知时，您必须保留由 RegisterDeviceNotification 编辑的句柄 return 并将其传递给 UnregisterDeviceNotification。
记录打包错误
您声明了压缩记录。这是个错误。由于我不清楚的原因，Delphi 开发人员打包他们的记录似乎是一个普遍的错误。打包导致性能不佳。更糟糕的是，在对对齐的记录执行互操作时，打包只会导致记录的布局不正确。这些记录没有打包。
此外，我认为您的记录不应包含 dbch_data 成员。这仅用于 DBT_CUSTOMEVENT，我认为这不适用于您。我会这样声明记录：
type
DEV_BROADCAST_HANDLE = record
dbch_size : DWORD ;
dbch_devicetype : DWORD ;
dbch_reserved : DWORD ;
dbch_handle : THandle ;
dbch_hdevnotify : HDEVNOTIFY ;
dbch_eventguid : TGUID ;
dbch_nameoffset : LONG ;
end;
弱错误检查
您确实检查了对 RegisterDeviceNotification 的调用的 return 值。那挺好的。但是，如果该调用失败，则您不会调用 GetLastError 来找出原因，如文档中所述。我会这样写电话：
var
DevNotificationHandle: HDEVNOTIFY;
....
DevNotificationHandle := RegisterDeviceNotification(...);
Win32Check(DevNotificationHandle <> 0);
这样，任何错误都将转换为异常，并带有代表 Win32 错误代码的文本错误消息。
dbch_devicetype
的值可能不正确
我认为你应该通过 DBT_DEVTYP_DEVICEINTERFACE 而不是 DBT_DEVTYP_HANDLE。如果您切换到 DBT_DEVTYP_DEVICEINTERFACE 并解决我上面提出的所有问题，那么您将收到通知。例如：
unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Classes,
Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.StdCtrls;
type
TForm1 = class(TForm)
Memo1: TMemo;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
private
FWindow: HWND;
FDevNotificationHandle: HDEVNOTIFY;
procedure WndMethod(var Message: TMessage);
function HandleDeviceChange(Event: DWORD; Data: Pointer): Boolean;
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
type
DEV_BROADCAST_HANDLE = record
dbch_size: DWORD;
dbch_devicetype: DWORD;
dbch_reserved: DWORD;
dbch_handle: THandle;
dbch_hdevnotify: HDEVNOTIFY;
dbch_eventguid: TGUID;
dbch_nameoffset: LONG;
end;
const
DBT_DEVTYP_DEVICEINTERFACE = [=12=]05;
GUID_IO_VOLUME_MOUNT: TGUID = '{B5804878-1A96-11D2-8FFD-00A0C9A06D32}';
procedure TForm1.FormCreate(Sender: TObject);
var
dbh: DEV_BROADCAST_HANDLE;
begin
FWindow := AllocateHWnd(WndMethod);
dbh := Default(DEV_BROADCAST_HANDLE);
dbh.dbch_size := SizeOf(dbh);
dbh.dbch_devicetype := DBT_DEVTYP_DEVICEINTERFACE;
dbh.dbch_eventguid := GUID_IO_VOLUME_MOUNT;
FDevNotificationHandle := RegisterDeviceNotification(FWindow, @dbh,
DEVICE_NOTIFY_WINDOW_HANDLE);
Win32Check(FDevNotificationHandle <> nil);
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
if FDevNotificationHandle <> nil then
Win32Check(UnregisterDeviceNotification(FDevNotificationHandle));
DeallocateHWnd(FWindow);
end;
procedure TForm1.WndMethod(var Message: TMessage);
begin
case Message.Msg of
WM_DEVICECHANGE:
Message.Result := ord(HandleDeviceChange(Message.WParam,
Pointer(Message.LParam)));
else
Message.Result := DefWindowProc(FWindow, Message.Msg, Message.WParam,
Message.LParam);
end;
end;
function TForm1.HandleDeviceChange(Event: DWORD; Data: Pointer): Boolean;
begin
Memo1.Lines.Add(Format('%4x', [Event]));
Result := True;
end;
end.
请注意，一组默认通知会广播到顶级 windows。所以你甚至可能不需要注册，因为我相信音量变化是默认设置的一部分。
编辑：在论坛上找到了一个关于此的组件。它称为 TSHChangeNotify，由 Elliott Shevinm 于 2000 年编写 (!)
See the forum thread here。它包含源代码和修复程序。
还有一篇由 Zarko Gajic 撰写的文章解释了它是如何工作的
found here
仅使用 VCL 时，它在 Delphi XE7 on Windows 8.1 中工作得很好。
更新： 我修改了代码，现在它可以在带有 Firemonkey 的 Delphi XE7 上运行。
The updated code can be found here.
我的设置方式是将 TSHChangeNotify.HardDriveOnly 设置为 FALSE
并将 TSHChangeNotify.Execute 放入主窗体 OnCreate 过程中。
感谢 Dalija 和 David，我收到了一些有用的信息和代码。
然而他们的回答并没有解决我的问题。
就像大卫在其中一条评论中所说的那样，他只是想 "push me in the right direction" 正如我自己在我的问题中所建议的那样。很公平。
我开始谷歌搜索 "guid_io_volume_mount c++" 看看我是否能在其他地方找到一些我可以移植的可用代码。
我看到这个论坛 post：http://www.mofeel.net/957-microsoft-public-vc-language/2343.aspx
OP 在他的代码中提到应该使用 CreateFileA，以便基本上 "monitor" 只要挂载点发生变化。
挂载点好像是盘符，比如C:、D:、E:等...
所以基本上发生的事情是使用以下代码
var
dbv: DEV_BROADCAST_HANDLE;
Size: Integer;
r: Pointer;
begin
Size := SizeOf(DEV_BROADCAST_HANDLE);
ZeroMemory(@dbv, Size);
dbv.dbch_size := Size;
dbv.dbch_devicetype := DBT_DEVTYP_HANDLE;
dbv.dbch_reserved := 0;
dbv.dbch_handle := CreateFileA('\.\C:', GENERIC_READ, FILE_SHARE_READ+FILE_SHARE_WRITE, nil, OPEN_EXISTING, FILE_FLAG_NO_BUFFERING + FILE_ATTRIBUTE_NORMAL + FILE_FLAG_SEQUENTIAL_SCAN, 0);
dbv.dbch_hdevnotify := 0;
dbv.dbch_nameoffset := 0;
r := RegisterDeviceNotification(fHandle, @dbv, DEVICE_NOTIFY_WINDOW_HANDLE);
if Assigned(r) then Result := True;
我们让 OS 知道每当 "C:" 改变了它的安装状态 (mount/dismount)，OS 就会向我们的 WndProc 消息捕捉器发送一条消息。
下面提供了我的完整源代码，仍然有一些问题，但到目前为止它提供了一个概念。
它至少可以检测到何时安装了指定的卷。
当您右键单击一个卷并 select "Eject".
时检测到卸载
现在请记住，这段代码不仅仅可以检测挂载点何时更改，this MSDN article has all the GUID's you need to do some pretty neat stuff.
unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Classes,
Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.StdCtrls, Vcl.dialogs;
type
TDeviceDetector = class
protected
fHandle: THandle;
fLogger: TMemo;
fOnCDROM_EXCLUSIVE_LOCK ,
fOnCDROM_EXCLUSIVE_UNLOCK ,
fOnDEVICE_BECOMING_READY ,
fOnDEVICE_EXTERNAL_REQUEST ,
fOnMEDIA_ARRIVAL ,
fOnMEDIA_EJECT_REQUEST ,
fOnMEDIA_REMOVAL ,
fOnVOLUME_CHANGE ,
fOnVOLUME_CHANGE_SIZE ,
fOnVOLUME_DISMOUNT ,
fOnVOLUME_DISMOUNT_FAILED ,
fOnVOLUME_FVE_STATUS_CHANGE ,
fOnVOLUME_LOCK ,
fOnVOLUME_LOCK_FAILED ,
fOnVOLUME_MOUNT ,
fOnVOLUME_NAME_CHANGE ,
fOnVOLUME_NEED_CHKDSK ,
fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE ,
fOnVOLUME_PREPARING_EJECT ,
fOnVOLUME_UNIQUE_ID_CHANGE ,
fOnVOLUME_UNLOCK ,
fOnVOLUME_WEARING_OUT : TNotifyEvent;
procedure WndProc(var Message: TMessage);
procedure Log(AStr: string);
public
constructor Create;
destructor Destroy; override;
function RegisterThis: Boolean;
property Logger: TMemo read fLogger write fLogger;
published
property OnCDROM_EXCLUSIVE_LOCK : TNotifyEvent read fOnCDROM_EXCLUSIVE_LOCK write fOnCDROM_EXCLUSIVE_LOCK ;
property OnCDROM_EXCLUSIVE_UNLOCK : TNotifyEvent read fOnCDROM_EXCLUSIVE_UNLOCK write fOnCDROM_EXCLUSIVE_UNLOCK ;
property OnDEVICE_BECOMING_READY : TNotifyEvent read fOnDEVICE_BECOMING_READY write fOnDEVICE_BECOMING_READY ;
property OnDEVICE_EXTERNAL_REQUEST : TNotifyEvent read fOnDEVICE_EXTERNAL_REQUEST write fOnDEVICE_EXTERNAL_REQUEST ;
property OnMEDIA_ARRIVAL : TNotifyEvent read fOnMEDIA_ARRIVAL write fOnMEDIA_ARRIVAL ;
property OnMEDIA_EJECT_REQUEST : TNotifyEvent read fOnMEDIA_EJECT_REQUEST write fOnMEDIA_EJECT_REQUEST ;
property OnMEDIA_REMOVAL : TNotifyEvent read fOnMEDIA_REMOVAL write fOnMEDIA_REMOVAL ;
property OnVOLUME_CHANGE : TNotifyEvent read fOnVOLUME_CHANGE write fOnVOLUME_CHANGE ;
property OnVOLUME_CHANGE_SIZE : TNotifyEvent read fOnVOLUME_CHANGE_SIZE write fOnVOLUME_CHANGE_SIZE ;
property OnVOLUME_DISMOUNT : TNotifyEvent read fOnVOLUME_DISMOUNT write fOnVOLUME_DISMOUNT ;
property OnVOLUME_DISMOUNT_FAILED : TNotifyEvent read fOnVOLUME_DISMOUNT_FAILED write fOnVOLUME_DISMOUNT_FAILED ;
property OnVOLUME_FVE_STATUS_CHANGE : TNotifyEvent read fOnVOLUME_FVE_STATUS_CHANGE write fOnVOLUME_FVE_STATUS_CHANGE ;
property OnVOLUME_LOCK : TNotifyEvent read fOnVOLUME_LOCK write fOnVOLUME_LOCK ;
property OnVOLUME_LOCK_FAILED : TNotifyEvent read fOnVOLUME_LOCK_FAILED write fOnVOLUME_LOCK_FAILED ;
property OnVOLUME_MOUNT : TNotifyEvent read fOnVOLUME_MOUNT write fOnVOLUME_MOUNT ;
property OnVOLUME_NAME_CHANGE : TNotifyEvent read fOnVOLUME_NAME_CHANGE write fOnVOLUME_NAME_CHANGE ;
property OnVOLUME_NEED_CHKDSK : TNotifyEvent read fOnVOLUME_NEED_CHKDSK write fOnVOLUME_NEED_CHKDSK ;
property OnVOLUME_PHYSICAL_CONFIGURATION_CHANGE : TNotifyEvent read fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE write fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE;
property OnVOLUME_PREPARING_EJECT : TNotifyEvent read fOnVOLUME_PREPARING_EJECT write fOnVOLUME_PREPARING_EJECT ;
property OnVOLUME_UNIQUE_ID_CHANGE : TNotifyEvent read fOnVOLUME_UNIQUE_ID_CHANGE write fOnVOLUME_UNIQUE_ID_CHANGE ;
property OnVOLUME_UNLOCK : TNotifyEvent read fOnVOLUME_UNLOCK write fOnVOLUME_UNLOCK ;
property OnVOLUME_WEARING_OUT : TNotifyEvent read fOnVOLUME_WEARING_OUT write fOnVOLUME_WEARING_OUT ;
end;
TForm1 = class(TForm)
Memo1: TMemo;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
private
end;
var
Form1: TForm1;
dd: TDeviceDetector;
implementation
{$R *.dfm}
type
PDevBroadcastHdr = ^DEV_BROADCAST_HDR;
DEV_BROADCAST_HDR = packed record
dbch_size : DWORD;
dbch_devicetype : DWORD;
dbch_reserved : DWORD;
end;
PDevBroadcastHandle = ^DEV_BROADCAST_HANDLE;
DEV_BROADCAST_HANDLE = record
dbch_size : DWORD;
dbch_devicetype : DWORD;
dbch_reserved : DWORD;
dbch_handle : THandle;
dbch_hdevnotify : HDEVNOTIFY;
dbch_eventguid : TGUID;
dbch_nameoffset : LONG;
dbch_data: array [0..0] of Byte;
end;
const
DEVICE_NOTIFY_ALL_INTERFACE_CLASSES = [=11=]000004;
DBT_CUSTOMEVENT = 06;
DBT_DEVTYP_HANDLE = [=11=]06;
GUID_IO_CDROM_EXCLUSIVE_LOCK : TGUID = '{bc56c139-7a10-47ee-a294-4c6a38f0149a}';
GUID_IO_CDROM_EXCLUSIVE_UNLOCK : TGUID = '{a3b6d27d-5e35-4885-81e5-ee18c00ed779}';
GUID_IO_DEVICE_BECOMING_READY : TGUID = '{d07433f0-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_DEVICE_EXTERNAL_REQUEST : TGUID = '{d07433d0-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_MEDIA_ARRIVAL : TGUID = '{d07433c0-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_MEDIA_EJECT_REQUEST : TGUID = '{d07433d1-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_MEDIA_REMOVAL : TGUID = '{d07433c1-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_VOLUME_CHANGE : TGUID = '{7373654a-812a-11d0-bec7-08002be2092f}';
GUID_IO_VOLUME_CHANGE_SIZE : TGUID = '{3a1625be-ad03-49f1-8ef8-6bbac182d1fd}';
GUID_IO_VOLUME_DISMOUNT : TGUID = '{d16a55e8-1059-11d2-8ffd-00a0c9a06d32}';
GUID_IO_VOLUME_DISMOUNT_FAILED : TGUID = '{E3C5B178-105D-11D2-8FFD-00A0C9A06D32}';
GUID_IO_VOLUME_FVE_STATUS_CHANGE : TGUID = '{062998b2-ee1f-4b6a-b857-e76cbbe9a6da}';
GUID_IO_VOLUME_LOCK : TGUID = '{50708874-c9af-11d1-8fef-00a0c9a06d32}';
GUID_IO_VOLUME_LOCK_FAILED : TGUID = '{ae2eed10-0ba8-11d2-8ffb-00a0c9a06d32}';
GUID_IO_VOLUME_MOUNT : TGUID = '{b5804878-1a96-11d2-8ffd-00a0c9a06d32}';
GUID_IO_VOLUME_NAME_CHANGE : TGUID = '{2de97f83-4c06-11d2-a532-00609713055a}';
GUID_IO_VOLUME_NEED_CHKDSK : TGUID = '{799a0960-0a0b-4e03-ad88-2fa7c6ce748a}';
GUID_IO_VOLUME_PHYSICAL_CONFIGURATION_CHANGE : TGUID = '{2de97f84-4c06-11d2-a532-00609713055a}';
GUID_IO_VOLUME_PREPARING_EJECT : TGUID = '{c79eb16e-0dac-4e7a-a86c-b25ceeaa88f6}';
GUID_IO_VOLUME_UNIQUE_ID_CHANGE : TGUID = '{af39da42-6622-41f5-970b-139d092fa3d9}';
GUID_IO_VOLUME_UNLOCK : TGUID = '{9a8c3d68-d0cb-11d1-8fef-00a0c9a06d32}';
GUID_IO_VOLUME_WEARING_OUT : TGUID = '{873113ca-1486-4508-82ac-c3b2e5297aaa}';
function WDE_GUID_To_String(AGUID: TGUID): string; //WDE stands for Windows Device Events
begin
if AGUID = GUID_IO_CDROM_EXCLUSIVE_LOCK then result := 'GUID_IO_CDROM_EXCLUSIVE_LOCK' else
if AGUID = GUID_IO_CDROM_EXCLUSIVE_UNLOCK then result := 'GUID_IO_CDROM_EXCLUSIVE_UNLOCK' else
if AGUID = GUID_IO_DEVICE_BECOMING_READY then result := 'GUID_IO_DEVICE_BECOMING_READY' else
if AGUID = GUID_IO_DEVICE_EXTERNAL_REQUEST then result := 'GUID_IO_DEVICE_BECOMING_READY' else
if AGUID = GUID_IO_MEDIA_ARRIVAL then result := 'GUID_IO_MEDIA_ARRIVAL' else
if AGUID = GUID_IO_MEDIA_EJECT_REQUEST then result := 'GUID_IO_MEDIA_EJECT_REQUEST' else
if AGUID = GUID_IO_MEDIA_REMOVAL then result := 'GUID_IO_MEDIA_REMOVAL' else
if AGUID = GUID_IO_VOLUME_CHANGE then result := 'GUID_IO_VOLUME_CHANGE' else
if AGUID = GUID_IO_VOLUME_CHANGE_SIZE then result := 'GUID_IO_VOLUME_CHANGE_SIZE' else
if AGUID = GUID_IO_VOLUME_DISMOUNT then result := 'GUID_IO_VOLUME_DISMOUNT' else
if AGUID = GUID_IO_VOLUME_DISMOUNT_FAILED then result := 'GUID_IO_VOLUME_DISMOUNT_FAILED' else
if AGUID = GUID_IO_VOLUME_FVE_STATUS_CHANGE then result := 'GUID_IO_VOLUME_FVE_STATUS_CHANGE' else
if AGUID = GUID_IO_VOLUME_LOCK then result := 'GUID_IO_VOLUME_LOCK' else
if AGUID = GUID_IO_VOLUME_LOCK_FAILED then result := 'GUID_IO_VOLUME_LOCK_FAILED' else
if AGUID = GUID_IO_VOLUME_MOUNT then result := 'GUID_IO_VOLUME_MOUNT' else
if AGUID = GUID_IO_VOLUME_NAME_CHANGE then result := 'GUID_IO_VOLUME_NAME_CHANGE' else
if AGUID = GUID_IO_VOLUME_NEED_CHKDSK then result := 'GUID_IO_VOLUME_NEED_CHKDSK' else
if AGUID = GUID_IO_VOLUME_PHYSICAL_CONFIGURATION_CHANGE then result := 'GUID_IO_VOLUME_PHYSICAL_CONFIGURATION_CHANGE' else
if AGUID = GUID_IO_VOLUME_PREPARING_EJECT then result := 'GUID_IO_VOLUME_PREPARING_EJECT' else
if AGUID = GUID_IO_VOLUME_UNIQUE_ID_CHANGE then result := 'GUID_IO_VOLUME_UNIQUE_ID_CHANGE' else
if AGUID = GUID_IO_VOLUME_UNLOCK then result := 'GUID_IO_VOLUME_UNLOCK' else
if AGUID = GUID_IO_VOLUME_WEARING_OUT then result := 'GUID_IO_VOLUME_WEARING_OUT';
end;
constructor TDeviceDetector.Create;
begin
inherited;
fHandle := AllocateHWnd(WndProc);
end;
destructor TDeviceDetector.Destroy;
begin
DeallocateHWnd(fHandle);
inherited;
end;
function TDeviceDetector.RegisterThis: Boolean;
var
dbv: DEV_BROADCAST_HANDLE;
Size: Integer;
r: Pointer;
begin
Size := SizeOf(DEV_BROADCAST_HANDLE);
ZeroMemory(@dbv, Size);
dbv.dbch_size := Size;
dbv.dbch_devicetype := DBT_DEVTYP_HANDLE;
dbv.dbch_reserved := 0;
dbv.dbch_handle := CreateFileA('\.\E:', GENERIC_READ, FILE_SHARE_READ + FILE_SHARE_WRITE, nil, OPEN_EXISTING, FILE_FLAG_NO_BUFFERING + FILE_ATTRIBUTE_NORMAL + FILE_FLAG_SEQUENTIAL_SCAN, 0);
dbv.dbch_hdevnotify := RegisterDeviceNotification(fHandle, @dbv, DEVICE_NOTIFY_ALL_INTERFACE_CLASSES);;
dbv.dbch_nameoffset := 0;
if Assigned(dbv.dbch_hdevnotify) then Result := True;
end;
procedure TDeviceDetector.WndProc(var Message: TMessage);
var data: PDevBroadcastHdr;
data_H: PDevBroadcastHandle;
begin
if Message.wParam = DBT_CUSTOMEVENT then //according to MSDN, DEV_BROADCAST_HANDLE structure is treated as a custom event.
begin
Data := PDevBroadcastHdr(Message.LParam); //we need to treat this custom evend a DEV_BROADCAST_HDR structure first...
if Data^.dbch_devicetype = DBT_DEVTYP_HANDLE then //then we check if the device type is DBT_DEVTYP_HANDLE
begin
data_H := PDevBroadcastHandle(Message.lParam); //if the device type is DBT_DEVTYP_HANDLE, we treat the custom event as a DEV_BROADCAST_HANDLE structure
//final step is to see what GUID the event of the structure DEV_BROADCAST_HANDLE has
Log(WDE_GUID_To_String(data_H^.dbch_eventguid));
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_CDROM_EXCLUSIVE_LOCK) = true then if assigned(fOnCDROM_EXCLUSIVE_LOCK) then fOnCDROM_EXCLUSIVE_LOCK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_CDROM_EXCLUSIVE_UNLOCK) = true then if assigned(fOnCDROM_EXCLUSIVE_UNLOCK) then fOnCDROM_EXCLUSIVE_UNLOCK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_DEVICE_BECOMING_READY) = true then if assigned(fOnDEVICE_BECOMING_READY) then fOnDEVICE_BECOMING_READY(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_DEVICE_EXTERNAL_REQUEST) = true then if assigned(fOnDEVICE_EXTERNAL_REQUEST) then fOnDEVICE_EXTERNAL_REQUEST(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_MEDIA_ARRIVAL) = true then if assigned(fOnMEDIA_ARRIVAL) then fOnMEDIA_ARRIVAL(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_MEDIA_EJECT_REQUEST) = true then if assigned(fOnMEDIA_EJECT_REQUEST) then fOnMEDIA_EJECT_REQUEST(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_MEDIA_REMOVAL) = true then if assigned(fOnMEDIA_REMOVAL) then fOnMEDIA_REMOVAL(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_CHANGE) = true then if assigned(fOnVOLUME_CHANGE) then fOnVOLUME_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_CHANGE_SIZE) = true then if assigned(fOnVOLUME_CHANGE_SIZE) then fOnVOLUME_CHANGE_SIZE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_DISMOUNT) = true then if assigned(fOnVOLUME_DISMOUNT) then fOnVOLUME_DISMOUNT(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_DISMOUNT_FAILED) = true then if assigned(fOnVOLUME_DISMOUNT_FAILED) then fOnVOLUME_DISMOUNT_FAILED(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_FVE_STATUS_CHANGE) = true then if assigned(fOnVOLUME_FVE_STATUS_CHANGE) then fOnVOLUME_FVE_STATUS_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_LOCK) = true then if assigned(fOnVOLUME_LOCK) then fOnVOLUME_LOCK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_LOCK_FAILED) = true then if assigned(fOnVOLUME_LOCK_FAILED) then fOnVOLUME_LOCK_FAILED(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_MOUNT) = true then if assigned(fOnVOLUME_MOUNT) then fOnVOLUME_MOUNT(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_NAME_CHANGE) = true then if assigned(fOnVOLUME_NAME_CHANGE) then fOnVOLUME_NAME_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_NEED_CHKDSK) = true then if assigned(fOnVOLUME_NEED_CHKDSK) then fOnVOLUME_NEED_CHKDSK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_PHYSICAL_CONFIGURATION_CHANGE) = true then if assigned(fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE) then fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_PREPARING_EJECT) = true then if assigned(fOnVOLUME_PREPARING_EJECT) then fOnVOLUME_PREPARING_EJECT(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_UNIQUE_ID_CHANGE) = true then if assigned(fOnVOLUME_UNIQUE_ID_CHANGE) then fOnVOLUME_UNIQUE_ID_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_UNLOCK) = true then if assigned(fOnVOLUME_UNLOCK) then fOnVOLUME_UNLOCK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_WEARING_OUT) = true then if assigned(fOnVOLUME_WEARING_OUT) then fOnVOLUME_WEARING_OUT(self);
end;
end;
end;
procedure TDeviceDetector.Log(AStr: string);
begin
fLogger.Lines.Add(AStr);
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
dd := TDeviceDetector.Create;
dd.Logger := Memo1;
if dd.RegisterThis = true then Memo1.Lines.Add('Registered!') else Memo1.Lines.Add('Failed to register!');
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
dd.free;
end;
end.
我正在尝试了解 MSDN 上有关设备事件的文档 以及如何在安装卷时触发通知。
我已使用以下 post 中提供的信息为 USB 设备执行此操作：detect usb drive/device using delphi
以及在互联网上找到的其他信息， 但我注意到直接挂载卷会更容易检测到。
所以我的问题是：如何在我的 Delphi 应用程序中实现设备事件处理？
我正在查看以下文档：https://msdn.microsoft.com/en-us/library/windows/desktop/aa363217(v=vs.85).aspx
但我真的不知道怎么弄，运行。
到目前为止，我已经尝试了以下代码，它编译正确， 但什么也没发生，请把我推向正确的方向：
PDevBroadcastHdr = ^DEV_BROADCAST_HDR;
DEV_BROADCAST_HDR = packed record
dbch_size : DWORD;
dbch_devicetype : DWORD;
dbch_reserved : DWORD;
end;
PDevBroadcastHandle = ^DEV_BROADCAST_HANDLE;
DEV_BROADCAST_HANDLE = packed record
dbch_size : DWORD ;
dbch_devicetype : DWORD ;
dbch_reserved : DWORD ;
dbch_handle : THandle ;
dbch_hdevnotify : HDEVNOTIFY ;
dbch_eventguid : TGUID ;
dbch_nameoffset : LongInt ;
dbch_data : byte ;
end;
...
procedure WMDeviceChange(var Msg: TMessage);
const
DBT_DEVTYP_HANDLE = [=12=]06;
GUID_IO_VOLUME_MOUNT: TGUID = '{B5804878-1A96-11D2-8FFD-00A0C9A06D32}';
...
function TForm1.RegisterThis: Boolean;
var
dbv: DEV_BROADCAST_HANDLE;
Size: Integer;
r: Pointer;
begin
Size := SizeOf(DEV_BROADCAST_HANDLE);
ZeroMemory(@dbv, Size);
dbv.dbch_size := Size;
dbv.dbch_devicetype := DBT_DEVTYP_HANDLE;
dbv.dbch_reserved := 0;
dbv.dbch_handle := 0;
dbv.dbch_hdevnotify := nil;
dbv.dbch_eventguid := GUID_IO_VOLUME_MOUNT;
dbv.dbch_nameoffset := 0;
dbv.dbch_data := 0;
r := RegisterDeviceNotification(FWindowHandle, @dbv, DEVICE_NOTIFY_WINDOW_HANDLE);
if Assigned(r) then Result := True;
end;
procedure TForm1.WMDeviceChange(var Msg: TMessage);
var
VData: PDevBroadcastHandle;
begin
ShowMessage('Hello!');
end;
您必须像这样声明您的 WMDeviceChange 方法才能接收消息：
procedure WMDeviceChange(var Msg: TMessage); message WM_DEVICECHANGE;
此外，由于您的 WMDeviceChange 方法是表单的一部分，您应该使用表单 window Handle 来注册消息。
r := RegisterDeviceNotification(Handle, @dbv, DEVICE_NOTIFY_WINDOW_HANDLE);
由于 Handle 可以在 Form 的生命周期内重新创建，因此您应该覆盖 Form 的 CreateWnd 方法并在那里添加注册。
或者更好的是，您可以将功能封装在另一个 class:
TDeviceDetector = class
protected
fHandle: THandle;
procedure WndProc(var Message: TMessage);
public
constructor Create;
destructor Destroy; override;
function RegisterThis: Boolean;
end;
constructor TDeviceDetector.Create;
begin
inherited;
fHandle := AllocateHWnd(WndProc);
end;
destructor TDeviceDetector.Destroy;
begin
DeallocateHWnd(fHandle);
inherited;
end;
function TDeviceDetector.RegisterThis: Boolean;
var
dbv: DEV_BROADCAST_HANDLE;
Size: Integer;
r: Pointer;
begin
Size := SizeOf(DEV_BROADCAST_HANDLE);
ZeroMemory(@dbv, Size);
dbv.dbch_size := Size;
dbv.dbch_devicetype := DBT_DEVTYP_HANDLE;
dbv.dbch_reserved := 0;
dbv.dbch_handle := 0;
dbv.dbch_hdevnotify := nil;
dbv.dbch_eventguid := GUID_IO_VOLUME_MOUNT;
dbv.dbch_nameoffset := 0;
dbv.dbch_data := 0;
r := RegisterDeviceNotification(fHandle, @dbv, DEVICE_NOTIFY_WINDOW_HANDLE);
if Assigned(r) then Result := True;
end;
procedure TDeviceDetector.WndProc(var Message: TMessage);
begin
if Message.Msg = WM_DEVICECHANGE then
begin
ShowMessage('Hello!');
end
else Message.Result := DefWindowProc(FHandle, Message.Msg, Message.wParam, Message.lParam); // Default Message Handler
end;
到目前为止，你的问题还挺多的。这是我能看到的。
收件人不正确
您正在将 window 句柄传递给 RegisterDeviceNotification。但是，您的 window 句柄是否实现了 WM_DEVICECHANGE 的消息处理程序还远未明确。我建议使用 AllocateHWnd 获取 window 句柄，并在您提供给 AllocateHWnd.
WM_DEVICECHANGE
调用UnregisterDeviceNotification失败
RegisterDeviceNotification 的文档说：
Device notification handles returned by RegisterDeviceNotification must be closed by calling the UnregisterDeviceNotification function when they are no longer needed.
你没有做到这一点。当您不想再收到通知时，您必须保留由 RegisterDeviceNotification 编辑的句柄 return 并将其传递给 UnregisterDeviceNotification。
记录打包错误
您声明了压缩记录。这是个错误。由于我不清楚的原因，Delphi 开发人员打包他们的记录似乎是一个普遍的错误。打包导致性能不佳。更糟糕的是，在对对齐的记录执行互操作时，打包只会导致记录的布局不正确。这些记录没有打包。
此外，我认为您的记录不应包含 dbch_data 成员。这仅用于 DBT_CUSTOMEVENT，我认为这不适用于您。我会这样声明记录：
type
DEV_BROADCAST_HANDLE = record
dbch_size : DWORD ;
dbch_devicetype : DWORD ;
dbch_reserved : DWORD ;
dbch_handle : THandle ;
dbch_hdevnotify : HDEVNOTIFY ;
dbch_eventguid : TGUID ;
dbch_nameoffset : LONG ;
end;
弱错误检查
您确实检查了对 RegisterDeviceNotification 的调用的 return 值。那挺好的。但是，如果该调用失败，则您不会调用 GetLastError 来找出原因，如文档中所述。我会这样写电话：
var
DevNotificationHandle: HDEVNOTIFY;
....
DevNotificationHandle := RegisterDeviceNotification(...);
Win32Check(DevNotificationHandle <> 0);
这样，任何错误都将转换为异常，并带有代表 Win32 错误代码的文本错误消息。
dbch_devicetype
我认为你应该通过 DBT_DEVTYP_DEVICEINTERFACE 而不是 DBT_DEVTYP_HANDLE。如果您切换到 DBT_DEVTYP_DEVICEINTERFACE 并解决我上面提出的所有问题，那么您将收到通知。例如：
unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Classes,
Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.StdCtrls;
type
TForm1 = class(TForm)
Memo1: TMemo;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
private
FWindow: HWND;
FDevNotificationHandle: HDEVNOTIFY;
procedure WndMethod(var Message: TMessage);
function HandleDeviceChange(Event: DWORD; Data: Pointer): Boolean;
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
type
DEV_BROADCAST_HANDLE = record
dbch_size: DWORD;
dbch_devicetype: DWORD;
dbch_reserved: DWORD;
dbch_handle: THandle;
dbch_hdevnotify: HDEVNOTIFY;
dbch_eventguid: TGUID;
dbch_nameoffset: LONG;
end;
const
DBT_DEVTYP_DEVICEINTERFACE = [=12=]05;
GUID_IO_VOLUME_MOUNT: TGUID = '{B5804878-1A96-11D2-8FFD-00A0C9A06D32}';
procedure TForm1.FormCreate(Sender: TObject);
var
dbh: DEV_BROADCAST_HANDLE;
begin
FWindow := AllocateHWnd(WndMethod);
dbh := Default(DEV_BROADCAST_HANDLE);
dbh.dbch_size := SizeOf(dbh);
dbh.dbch_devicetype := DBT_DEVTYP_DEVICEINTERFACE;
dbh.dbch_eventguid := GUID_IO_VOLUME_MOUNT;
FDevNotificationHandle := RegisterDeviceNotification(FWindow, @dbh,
DEVICE_NOTIFY_WINDOW_HANDLE);
Win32Check(FDevNotificationHandle <> nil);
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
if FDevNotificationHandle <> nil then
Win32Check(UnregisterDeviceNotification(FDevNotificationHandle));
DeallocateHWnd(FWindow);
end;
procedure TForm1.WndMethod(var Message: TMessage);
begin
case Message.Msg of
WM_DEVICECHANGE:
Message.Result := ord(HandleDeviceChange(Message.WParam,
Pointer(Message.LParam)));
else
Message.Result := DefWindowProc(FWindow, Message.Msg, Message.WParam,
Message.LParam);
end;
end;
function TForm1.HandleDeviceChange(Event: DWORD; Data: Pointer): Boolean;
begin
Memo1.Lines.Add(Format('%4x', [Event]));
Result := True;
end;
end.
请注意，一组默认通知会广播到顶级 windows。所以你甚至可能不需要注册，因为我相信音量变化是默认设置的一部分。
编辑：在论坛上找到了一个关于此的组件。它称为 TSHChangeNotify，由 Elliott Shevinm 于 2000 年编写 (!)
See the forum thread here。它包含源代码和修复程序。 还有一篇由 Zarko Gajic 撰写的文章解释了它是如何工作的 found here
仅使用 VCL 时，它在 Delphi XE7 on Windows 8.1 中工作得很好。
更新： 我修改了代码，现在它可以在带有 Firemonkey 的 Delphi XE7 上运行。 The updated code can be found here.
我的设置方式是将 TSHChangeNotify.HardDriveOnly 设置为 FALSE
并将 TSHChangeNotify.Execute 放入主窗体 OnCreate 过程中。
感谢 Dalija 和 David，我收到了一些有用的信息和代码。
然而他们的回答并没有解决我的问题。
就像大卫在其中一条评论中所说的那样，他只是想 "push me in the right direction" 正如我自己在我的问题中所建议的那样。很公平。
我开始谷歌搜索 "guid_io_volume_mount c++" 看看我是否能在其他地方找到一些我可以移植的可用代码。
我看到这个论坛 post：http://www.mofeel.net/957-microsoft-public-vc-language/2343.aspx
OP 在他的代码中提到应该使用 CreateFileA，以便基本上 "monitor" 只要挂载点发生变化。
挂载点好像是盘符，比如C:、D:、E:等...
所以基本上发生的事情是使用以下代码
var
dbv: DEV_BROADCAST_HANDLE;
Size: Integer;
r: Pointer;
begin
Size := SizeOf(DEV_BROADCAST_HANDLE);
ZeroMemory(@dbv, Size);
dbv.dbch_size := Size;
dbv.dbch_devicetype := DBT_DEVTYP_HANDLE;
dbv.dbch_reserved := 0;
dbv.dbch_handle := CreateFileA('\.\C:', GENERIC_READ, FILE_SHARE_READ+FILE_SHARE_WRITE, nil, OPEN_EXISTING, FILE_FLAG_NO_BUFFERING + FILE_ATTRIBUTE_NORMAL + FILE_FLAG_SEQUENTIAL_SCAN, 0);
dbv.dbch_hdevnotify := 0;
dbv.dbch_nameoffset := 0;
r := RegisterDeviceNotification(fHandle, @dbv, DEVICE_NOTIFY_WINDOW_HANDLE);
if Assigned(r) then Result := True;
我们让 OS 知道每当 "C:" 改变了它的安装状态 (mount/dismount)，OS 就会向我们的 WndProc 消息捕捉器发送一条消息。
下面提供了我的完整源代码，仍然有一些问题，但到目前为止它提供了一个概念。
它至少可以检测到何时安装了指定的卷。 当您右键单击一个卷并 select "Eject".
时检测到卸载现在请记住，这段代码不仅仅可以检测挂载点何时更改，this MSDN article has all the GUID's you need to do some pretty neat stuff.
unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Classes,
Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.StdCtrls, Vcl.dialogs;
type
TDeviceDetector = class
protected
fHandle: THandle;
fLogger: TMemo;
fOnCDROM_EXCLUSIVE_LOCK ,
fOnCDROM_EXCLUSIVE_UNLOCK ,
fOnDEVICE_BECOMING_READY ,
fOnDEVICE_EXTERNAL_REQUEST ,
fOnMEDIA_ARRIVAL ,
fOnMEDIA_EJECT_REQUEST ,
fOnMEDIA_REMOVAL ,
fOnVOLUME_CHANGE ,
fOnVOLUME_CHANGE_SIZE ,
fOnVOLUME_DISMOUNT ,
fOnVOLUME_DISMOUNT_FAILED ,
fOnVOLUME_FVE_STATUS_CHANGE ,
fOnVOLUME_LOCK ,
fOnVOLUME_LOCK_FAILED ,
fOnVOLUME_MOUNT ,
fOnVOLUME_NAME_CHANGE ,
fOnVOLUME_NEED_CHKDSK ,
fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE ,
fOnVOLUME_PREPARING_EJECT ,
fOnVOLUME_UNIQUE_ID_CHANGE ,
fOnVOLUME_UNLOCK ,
fOnVOLUME_WEARING_OUT : TNotifyEvent;
procedure WndProc(var Message: TMessage);
procedure Log(AStr: string);
public
constructor Create;
destructor Destroy; override;
function RegisterThis: Boolean;
property Logger: TMemo read fLogger write fLogger;
published
property OnCDROM_EXCLUSIVE_LOCK : TNotifyEvent read fOnCDROM_EXCLUSIVE_LOCK write fOnCDROM_EXCLUSIVE_LOCK ;
property OnCDROM_EXCLUSIVE_UNLOCK : TNotifyEvent read fOnCDROM_EXCLUSIVE_UNLOCK write fOnCDROM_EXCLUSIVE_UNLOCK ;
property OnDEVICE_BECOMING_READY : TNotifyEvent read fOnDEVICE_BECOMING_READY write fOnDEVICE_BECOMING_READY ;
property OnDEVICE_EXTERNAL_REQUEST : TNotifyEvent read fOnDEVICE_EXTERNAL_REQUEST write fOnDEVICE_EXTERNAL_REQUEST ;
property OnMEDIA_ARRIVAL : TNotifyEvent read fOnMEDIA_ARRIVAL write fOnMEDIA_ARRIVAL ;
property OnMEDIA_EJECT_REQUEST : TNotifyEvent read fOnMEDIA_EJECT_REQUEST write fOnMEDIA_EJECT_REQUEST ;
property OnMEDIA_REMOVAL : TNotifyEvent read fOnMEDIA_REMOVAL write fOnMEDIA_REMOVAL ;
property OnVOLUME_CHANGE : TNotifyEvent read fOnVOLUME_CHANGE write fOnVOLUME_CHANGE ;
property OnVOLUME_CHANGE_SIZE : TNotifyEvent read fOnVOLUME_CHANGE_SIZE write fOnVOLUME_CHANGE_SIZE ;
property OnVOLUME_DISMOUNT : TNotifyEvent read fOnVOLUME_DISMOUNT write fOnVOLUME_DISMOUNT ;
property OnVOLUME_DISMOUNT_FAILED : TNotifyEvent read fOnVOLUME_DISMOUNT_FAILED write fOnVOLUME_DISMOUNT_FAILED ;
property OnVOLUME_FVE_STATUS_CHANGE : TNotifyEvent read fOnVOLUME_FVE_STATUS_CHANGE write fOnVOLUME_FVE_STATUS_CHANGE ;
property OnVOLUME_LOCK : TNotifyEvent read fOnVOLUME_LOCK write fOnVOLUME_LOCK ;
property OnVOLUME_LOCK_FAILED : TNotifyEvent read fOnVOLUME_LOCK_FAILED write fOnVOLUME_LOCK_FAILED ;
property OnVOLUME_MOUNT : TNotifyEvent read fOnVOLUME_MOUNT write fOnVOLUME_MOUNT ;
property OnVOLUME_NAME_CHANGE : TNotifyEvent read fOnVOLUME_NAME_CHANGE write fOnVOLUME_NAME_CHANGE ;
property OnVOLUME_NEED_CHKDSK : TNotifyEvent read fOnVOLUME_NEED_CHKDSK write fOnVOLUME_NEED_CHKDSK ;
property OnVOLUME_PHYSICAL_CONFIGURATION_CHANGE : TNotifyEvent read fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE write fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE;
property OnVOLUME_PREPARING_EJECT : TNotifyEvent read fOnVOLUME_PREPARING_EJECT write fOnVOLUME_PREPARING_EJECT ;
property OnVOLUME_UNIQUE_ID_CHANGE : TNotifyEvent read fOnVOLUME_UNIQUE_ID_CHANGE write fOnVOLUME_UNIQUE_ID_CHANGE ;
property OnVOLUME_UNLOCK : TNotifyEvent read fOnVOLUME_UNLOCK write fOnVOLUME_UNLOCK ;
property OnVOLUME_WEARING_OUT : TNotifyEvent read fOnVOLUME_WEARING_OUT write fOnVOLUME_WEARING_OUT ;
end;
TForm1 = class(TForm)
Memo1: TMemo;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
private
end;
var
Form1: TForm1;
dd: TDeviceDetector;
implementation
{$R *.dfm}
type
PDevBroadcastHdr = ^DEV_BROADCAST_HDR;
DEV_BROADCAST_HDR = packed record
dbch_size : DWORD;
dbch_devicetype : DWORD;
dbch_reserved : DWORD;
end;
PDevBroadcastHandle = ^DEV_BROADCAST_HANDLE;
DEV_BROADCAST_HANDLE = record
dbch_size : DWORD;
dbch_devicetype : DWORD;
dbch_reserved : DWORD;
dbch_handle : THandle;
dbch_hdevnotify : HDEVNOTIFY;
dbch_eventguid : TGUID;
dbch_nameoffset : LONG;
dbch_data: array [0..0] of Byte;
end;
const
DEVICE_NOTIFY_ALL_INTERFACE_CLASSES = [=11=]000004;
DBT_CUSTOMEVENT = 06;
DBT_DEVTYP_HANDLE = [=11=]06;
GUID_IO_CDROM_EXCLUSIVE_LOCK : TGUID = '{bc56c139-7a10-47ee-a294-4c6a38f0149a}';
GUID_IO_CDROM_EXCLUSIVE_UNLOCK : TGUID = '{a3b6d27d-5e35-4885-81e5-ee18c00ed779}';
GUID_IO_DEVICE_BECOMING_READY : TGUID = '{d07433f0-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_DEVICE_EXTERNAL_REQUEST : TGUID = '{d07433d0-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_MEDIA_ARRIVAL : TGUID = '{d07433c0-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_MEDIA_EJECT_REQUEST : TGUID = '{d07433d1-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_MEDIA_REMOVAL : TGUID = '{d07433c1-a98e-11d2-917a-00a0c9068ff3}';
GUID_IO_VOLUME_CHANGE : TGUID = '{7373654a-812a-11d0-bec7-08002be2092f}';
GUID_IO_VOLUME_CHANGE_SIZE : TGUID = '{3a1625be-ad03-49f1-8ef8-6bbac182d1fd}';
GUID_IO_VOLUME_DISMOUNT : TGUID = '{d16a55e8-1059-11d2-8ffd-00a0c9a06d32}';
GUID_IO_VOLUME_DISMOUNT_FAILED : TGUID = '{E3C5B178-105D-11D2-8FFD-00A0C9A06D32}';
GUID_IO_VOLUME_FVE_STATUS_CHANGE : TGUID = '{062998b2-ee1f-4b6a-b857-e76cbbe9a6da}';
GUID_IO_VOLUME_LOCK : TGUID = '{50708874-c9af-11d1-8fef-00a0c9a06d32}';
GUID_IO_VOLUME_LOCK_FAILED : TGUID = '{ae2eed10-0ba8-11d2-8ffb-00a0c9a06d32}';
GUID_IO_VOLUME_MOUNT : TGUID = '{b5804878-1a96-11d2-8ffd-00a0c9a06d32}';
GUID_IO_VOLUME_NAME_CHANGE : TGUID = '{2de97f83-4c06-11d2-a532-00609713055a}';
GUID_IO_VOLUME_NEED_CHKDSK : TGUID = '{799a0960-0a0b-4e03-ad88-2fa7c6ce748a}';
GUID_IO_VOLUME_PHYSICAL_CONFIGURATION_CHANGE : TGUID = '{2de97f84-4c06-11d2-a532-00609713055a}';
GUID_IO_VOLUME_PREPARING_EJECT : TGUID = '{c79eb16e-0dac-4e7a-a86c-b25ceeaa88f6}';
GUID_IO_VOLUME_UNIQUE_ID_CHANGE : TGUID = '{af39da42-6622-41f5-970b-139d092fa3d9}';
GUID_IO_VOLUME_UNLOCK : TGUID = '{9a8c3d68-d0cb-11d1-8fef-00a0c9a06d32}';
GUID_IO_VOLUME_WEARING_OUT : TGUID = '{873113ca-1486-4508-82ac-c3b2e5297aaa}';
function WDE_GUID_To_String(AGUID: TGUID): string; //WDE stands for Windows Device Events
begin
if AGUID = GUID_IO_CDROM_EXCLUSIVE_LOCK then result := 'GUID_IO_CDROM_EXCLUSIVE_LOCK' else
if AGUID = GUID_IO_CDROM_EXCLUSIVE_UNLOCK then result := 'GUID_IO_CDROM_EXCLUSIVE_UNLOCK' else
if AGUID = GUID_IO_DEVICE_BECOMING_READY then result := 'GUID_IO_DEVICE_BECOMING_READY' else
if AGUID = GUID_IO_DEVICE_EXTERNAL_REQUEST then result := 'GUID_IO_DEVICE_BECOMING_READY' else
if AGUID = GUID_IO_MEDIA_ARRIVAL then result := 'GUID_IO_MEDIA_ARRIVAL' else
if AGUID = GUID_IO_MEDIA_EJECT_REQUEST then result := 'GUID_IO_MEDIA_EJECT_REQUEST' else
if AGUID = GUID_IO_MEDIA_REMOVAL then result := 'GUID_IO_MEDIA_REMOVAL' else
if AGUID = GUID_IO_VOLUME_CHANGE then result := 'GUID_IO_VOLUME_CHANGE' else
if AGUID = GUID_IO_VOLUME_CHANGE_SIZE then result := 'GUID_IO_VOLUME_CHANGE_SIZE' else
if AGUID = GUID_IO_VOLUME_DISMOUNT then result := 'GUID_IO_VOLUME_DISMOUNT' else
if AGUID = GUID_IO_VOLUME_DISMOUNT_FAILED then result := 'GUID_IO_VOLUME_DISMOUNT_FAILED' else
if AGUID = GUID_IO_VOLUME_FVE_STATUS_CHANGE then result := 'GUID_IO_VOLUME_FVE_STATUS_CHANGE' else
if AGUID = GUID_IO_VOLUME_LOCK then result := 'GUID_IO_VOLUME_LOCK' else
if AGUID = GUID_IO_VOLUME_LOCK_FAILED then result := 'GUID_IO_VOLUME_LOCK_FAILED' else
if AGUID = GUID_IO_VOLUME_MOUNT then result := 'GUID_IO_VOLUME_MOUNT' else
if AGUID = GUID_IO_VOLUME_NAME_CHANGE then result := 'GUID_IO_VOLUME_NAME_CHANGE' else
if AGUID = GUID_IO_VOLUME_NEED_CHKDSK then result := 'GUID_IO_VOLUME_NEED_CHKDSK' else
if AGUID = GUID_IO_VOLUME_PHYSICAL_CONFIGURATION_CHANGE then result := 'GUID_IO_VOLUME_PHYSICAL_CONFIGURATION_CHANGE' else
if AGUID = GUID_IO_VOLUME_PREPARING_EJECT then result := 'GUID_IO_VOLUME_PREPARING_EJECT' else
if AGUID = GUID_IO_VOLUME_UNIQUE_ID_CHANGE then result := 'GUID_IO_VOLUME_UNIQUE_ID_CHANGE' else
if AGUID = GUID_IO_VOLUME_UNLOCK then result := 'GUID_IO_VOLUME_UNLOCK' else
if AGUID = GUID_IO_VOLUME_WEARING_OUT then result := 'GUID_IO_VOLUME_WEARING_OUT';
end;
constructor TDeviceDetector.Create;
begin
inherited;
fHandle := AllocateHWnd(WndProc);
end;
destructor TDeviceDetector.Destroy;
begin
DeallocateHWnd(fHandle);
inherited;
end;
function TDeviceDetector.RegisterThis: Boolean;
var
dbv: DEV_BROADCAST_HANDLE;
Size: Integer;
r: Pointer;
begin
Size := SizeOf(DEV_BROADCAST_HANDLE);
ZeroMemory(@dbv, Size);
dbv.dbch_size := Size;
dbv.dbch_devicetype := DBT_DEVTYP_HANDLE;
dbv.dbch_reserved := 0;
dbv.dbch_handle := CreateFileA('\.\E:', GENERIC_READ, FILE_SHARE_READ + FILE_SHARE_WRITE, nil, OPEN_EXISTING, FILE_FLAG_NO_BUFFERING + FILE_ATTRIBUTE_NORMAL + FILE_FLAG_SEQUENTIAL_SCAN, 0);
dbv.dbch_hdevnotify := RegisterDeviceNotification(fHandle, @dbv, DEVICE_NOTIFY_ALL_INTERFACE_CLASSES);;
dbv.dbch_nameoffset := 0;
if Assigned(dbv.dbch_hdevnotify) then Result := True;
end;
procedure TDeviceDetector.WndProc(var Message: TMessage);
var data: PDevBroadcastHdr;
data_H: PDevBroadcastHandle;
begin
if Message.wParam = DBT_CUSTOMEVENT then //according to MSDN, DEV_BROADCAST_HANDLE structure is treated as a custom event.
begin
Data := PDevBroadcastHdr(Message.LParam); //we need to treat this custom evend a DEV_BROADCAST_HDR structure first...
if Data^.dbch_devicetype = DBT_DEVTYP_HANDLE then //then we check if the device type is DBT_DEVTYP_HANDLE
begin
data_H := PDevBroadcastHandle(Message.lParam); //if the device type is DBT_DEVTYP_HANDLE, we treat the custom event as a DEV_BROADCAST_HANDLE structure
//final step is to see what GUID the event of the structure DEV_BROADCAST_HANDLE has
Log(WDE_GUID_To_String(data_H^.dbch_eventguid));
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_CDROM_EXCLUSIVE_LOCK) = true then if assigned(fOnCDROM_EXCLUSIVE_LOCK) then fOnCDROM_EXCLUSIVE_LOCK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_CDROM_EXCLUSIVE_UNLOCK) = true then if assigned(fOnCDROM_EXCLUSIVE_UNLOCK) then fOnCDROM_EXCLUSIVE_UNLOCK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_DEVICE_BECOMING_READY) = true then if assigned(fOnDEVICE_BECOMING_READY) then fOnDEVICE_BECOMING_READY(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_DEVICE_EXTERNAL_REQUEST) = true then if assigned(fOnDEVICE_EXTERNAL_REQUEST) then fOnDEVICE_EXTERNAL_REQUEST(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_MEDIA_ARRIVAL) = true then if assigned(fOnMEDIA_ARRIVAL) then fOnMEDIA_ARRIVAL(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_MEDIA_EJECT_REQUEST) = true then if assigned(fOnMEDIA_EJECT_REQUEST) then fOnMEDIA_EJECT_REQUEST(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_MEDIA_REMOVAL) = true then if assigned(fOnMEDIA_REMOVAL) then fOnMEDIA_REMOVAL(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_CHANGE) = true then if assigned(fOnVOLUME_CHANGE) then fOnVOLUME_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_CHANGE_SIZE) = true then if assigned(fOnVOLUME_CHANGE_SIZE) then fOnVOLUME_CHANGE_SIZE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_DISMOUNT) = true then if assigned(fOnVOLUME_DISMOUNT) then fOnVOLUME_DISMOUNT(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_DISMOUNT_FAILED) = true then if assigned(fOnVOLUME_DISMOUNT_FAILED) then fOnVOLUME_DISMOUNT_FAILED(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_FVE_STATUS_CHANGE) = true then if assigned(fOnVOLUME_FVE_STATUS_CHANGE) then fOnVOLUME_FVE_STATUS_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_LOCK) = true then if assigned(fOnVOLUME_LOCK) then fOnVOLUME_LOCK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_LOCK_FAILED) = true then if assigned(fOnVOLUME_LOCK_FAILED) then fOnVOLUME_LOCK_FAILED(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_MOUNT) = true then if assigned(fOnVOLUME_MOUNT) then fOnVOLUME_MOUNT(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_NAME_CHANGE) = true then if assigned(fOnVOLUME_NAME_CHANGE) then fOnVOLUME_NAME_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_NEED_CHKDSK) = true then if assigned(fOnVOLUME_NEED_CHKDSK) then fOnVOLUME_NEED_CHKDSK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_PHYSICAL_CONFIGURATION_CHANGE) = true then if assigned(fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE) then fOnVOLUME_PHYSICAL_CONFIGURATION_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_PREPARING_EJECT) = true then if assigned(fOnVOLUME_PREPARING_EJECT) then fOnVOLUME_PREPARING_EJECT(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_UNIQUE_ID_CHANGE) = true then if assigned(fOnVOLUME_UNIQUE_ID_CHANGE) then fOnVOLUME_UNIQUE_ID_CHANGE(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_UNLOCK) = true then if assigned(fOnVOLUME_UNLOCK) then fOnVOLUME_UNLOCK(self) else
if IsEqualGUID(data_H^.dbch_eventguid, GUID_IO_VOLUME_WEARING_OUT) = true then if assigned(fOnVOLUME_WEARING_OUT) then fOnVOLUME_WEARING_OUT(self);
end;
end;
end;
procedure TDeviceDetector.Log(AStr: string);
begin
fLogger.Lines.Add(AStr);
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
dd := TDeviceDetector.Create;
dd.Logger := Memo1;
if dd.RegisterThis = true then Memo1.Lines.Add('Registered!') else Memo1.Lines.Add('Failed to register!');
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
dd.free;
end;
end.