将USB检测添加到无格式的{dpr}纯Delphi应用程序

是否可以将usb检测添加到无格式（仅限dpr）的Delphi程序中？ 我已经编写了detection类，但它似乎只有在向程序添加表单时才起作用

这是上课时间

unit uMyUSB;

interface

uses

  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Classes,
  Winapi.ShellApi, Vcl.Dialogs;

// Start of Declarations

const
  DBT_DEVICEARRIVAL = $00008000;
  DBT_DEVICEREMOVECOMPLETE = $00008004;
  DBT_DEVTYP_VOLUME = $00000002;
  DBTF_MEDIA = $00000001;
  USB_INTERFACE = $00000005;

  // Device structs
type
  PDevBroadcastDeviceInterface = ^_DEV_BROADCAST_HDR;

  _DEV_BROADCAST_HDR = packed record
    dbch_size: DWORD;
    dbch_devicetype: DWORD;
    dbch_reserved: DWORD;
  end;

  DEV_BROADCAST_HDR = _DEV_BROADCAST_HDR;
  TDevBroadcastHeader = DEV_BROADCAST_HDR;
  PDevBroadcastHeader = ^TDevBroadcastHeader;

type
  _DEV_BROADCAST_VOLUME = packed record
    dbch_size: DWORD;
    dbch_devicetype: DWORD;
    dbch_reserved: DWORD;
    dbcv_unitmask: DWORD;
    dbcv_flags: WORD;
  end;

  DEV_BROADCAST_VOLUME = _DEV_BROADCAST_VOLUME;
  TDevBroadcastVolume = DEV_BROADCAST_VOLUME;
  PDevBroadcastVolume = ^TDevBroadcastVolume;

  // End of Declarations

  type

  TUSB = class(TObject)
  private
    FHandle: HWND;
    procedure WMDeviceChange(var Msg: TMessage); message WM_DEVICECHANGE;
    procedure WinMethod(var Msg: TMessage);
    procedure RegisterUsbHandler;
    { Public declarations }
  public
    { Public declarations }
    constructor Create();
    destructor Destroy(); override;
  end;

implementation

constructor TUSB.Create();
begin
  inherited Create;
  FHandle := AllocateHWnd(WinMethod);
  RegisterUsbHandler;
end;

destructor TUSB.Destroy();
begin
  DeallocateHWnd(FHandle);
  inherited Destroy;
end;

procedure TUSB.WinMethod(var Msg: TMessage);
begin
  if (Msg.Msg = WM_DEVICECHANGE) then
  begin
    WMDeviceChange(Msg);
  end
  else
  begin
    Msg.Result := DefWindowProc(FHandle, Msg.Msg, Msg.WParam, Msg.LParam);
  end;

end;

procedure TUSB.RegisterUsbHandler;
var
  rDbi: _DEV_BROADCAST_HDR;
  iSize: Integer;
begin
  iSize := SizeOf(_DEV_BROADCAST_HDR);
  ZeroMemory(@rDbi, iSize);
  rDbi.dbch_size := iSize;
  rDbi.dbch_devicetype := USB_INTERFACE;
  rDbi.dbch_reserved := 0;

  RegisterDeviceNotification(FHandle, @rDbi, DEVICE_NOTIFY_WINDOW_HANDLE);
end;

procedure TUSB.WMDeviceChange(var Msg: TMessage);
var
  lpdbhHeader: PDevBroadcastHeader;

begin
  lpdbhHeader := PDevBroadcastHeader(Msg.LParam);

    case Msg.WParam of
      DBT_DEVICEARRIVAL:
        begin
          if (lpdbhHeader^.dbch_devicetype = DBT_DEVTYP_VOLUME) then
          begin
            ShowMessage('Inserted');

          end;

        end;
      DBT_DEVICEREMOVECOMPLETE:
        begin
          if (lpdbhHeader^.dbch_devicetype = DBT_DEVTYP_VOLUME) then
          begin
            ShowMessage('Removed');
          end;

        end;
    end;


end;

这是测试单元

// My dpr Program

program TestUSB;

uses
  System.SysUtils,
  System.Classes,
  uMyUSB in 'Sources\uMyUSB.pas';

{$R *.res}

var
  FUSB: TUSB;

begin
{$WARNINGS OFF}
  ReportMemoryLeaksOnShutdown := DebugHook <> 0;
{$WARNINGS ON}

  FUSB := TUSB.Create();

// Loop to keep the Program Running Continually.
  while 1 = 1 do
  begin
  // Do Something
  end;

  FreeandNil(CustomUsb);

end.

//我的dpr程序
程序测试USB；
使用
System.SysUtils，
系统,班级,，
“来源\ uMyUSB.pas”中的uMyUSB；
{$R*.res}
变量
FUSB:TUSB；
开始
{$WARNINGS OFF}
ReportMemoryLeaksOnShutdown:=DebugHook 0；
{$WARNINGS ON}
FUSB:=TUSB.Create（）；
//循环以保持程序持续运行。
而1=1做
开始
//做点什么
结束；
FreeandNil（自定义USB）；
结束。

如何使无格式程序接受USB更改（WM_DEVICECHANGE）命令

非常感谢

---

Delphi XE7。

尽管消息是同步的，也就是说是非排队的，但您确实需要调度消息才能传递同步消息。通常，当您调用

GetMessage

或类似函数时，消息分派由消息循环完成

您的应用程序没有消息循环，也不发送消息。您只需要安排程序发送消息。添加一个消息循环就可以了。但是你只需要做一些发送消息的事情。不需要是一个完整的消息循环。例如，您可以将循环替换为：

while True do
  SendMessage(hwnd, WM_NULL, 0, 0);

这就是您所需要的，因为

SendMessage

是发送消息的函数之一

您需要决定使用哪个窗口句柄。可以使用创建的窗口句柄。或者，您可能会将消息发送到值为

0

的无效窗口句柄

或者您可以决定运行标准消息循环：

while GetMessage(Msg, 0, 0, 0) do
begin
  TranslateMessage(Msg);
  DispatchMessage(Msg);
end;

---

默认情况下，控制台应用程序没有消息循环。看一看，跟往常一样精彩的解释。谢谢