delphi – 如何使用WH_CBT挂钩和WndProc捕获发送到窗口的所有消

我正在构建一个dll内部的日志系统,其主要任务是捕获目标应用程序的一些特定 Windows消息并执行一些任务.但遗憾的是,WndProc方法(WM_GETMINMAXINFO)只捕获了一条消息.我错过了什么？为什么不将所有Windows消息写入日志？

这是解决问题的最小示例代码

DLL

library LogDll;

uses
  Winapi.Windows,Winapi.Messages,System.IOUtils,System.SysUtils,System.Classes;

{$R *.res}

type
  TLogInspector = class
  private
    WndHandle: THandle;
    ProcAddrInst: Pointer;
    OrgWndProc: Pointer;
  protected
    function CallOrgWndProc(Message: TMessage): LRESULT;
    procedure WndProc(var Message: TMessage); virtual;
  public
    constructor Create(AHandle: THandle); virtual;
  end;

var
  MainHook: HHook;
  Log : TLogInspector;

function TLogInspector.CallOrgWndProc(Message: TMessage): LRESULT;
begin
  Result := CallWindowProc(OrgWndProc,WndHandle,Message.Msg,Message.wParam,Message.lParam);
end;

constructor TLogInspector.Create(AHandle: THandle);
begin
  OrgWndProc := Pointer(GetWindowLongPtr(AHandle,GWL_WNDPROC));
  ProcAddrInst := MakeObjectInstance(WndProc);
  WndHandle := AHandle;
  SetWindowLongPtr(WndHandle,GWL_WNDPROC,LONG_PTR(ProcAddrInst));
end;

procedure TLogInspector.WndProc(var Message: TMessage);
begin
  //log the current message
  TFile.AppendAllText('C:Delphilog.txt','WndProc '+IntToStr(Message.Msg)+sLineBreak);
  //call the org WndProc 
  Message.Result := CallOrgWndProc(Message);
end;


function HookCallBack(nCode: Integer;  _WPARAM: WPARAM; _LPARAM: LPARAM): LRESULT;  stdcall;
var
  lpClassName : array [0 .. 256] of Char;
begin
  if nCode = HCBT_CREATEWND then
    begin
      GetClassName(_WPARAM,lpClassName,256);
      if lpClassName = 'TForm1' then
        Log:=  TLogInspector.Create(_WPARAM);
    end;

  Result := CallNextHookEx(MainHook,nCode,_WPARAM,_LPARAM);
end;


procedure InitLog; stdcall;
begin
  MainHook := SetWindowsHookEx(WH_CBT,@HookCallBack,GetCurrentThreadId);
end;

procedure DoneLog; stdcall;
begin
  UnhookWindowsHookEx(MainHook);
end;

exports
   InitLog,DoneLog;

begin
end.

应用

type
  TForm1 = class(TForm)
    Button1: TButton;
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

  procedure InitLog; stdcall;  external 'LogDll.dll' name 'InitLog';
  procedure DoneLog; stdcall;  external 'LogDll.dll' name 'DoneLog';

implementation

{$R *.dfm}



initialization
 InitLog;
finalization
 DoneLog;
end.

function HookCallBack(nCode: Integer; wParam: WPARAM; lParam: LPARAM): LRESULT; stdcall;
var
  lpClassName : array [0 .. 256] of Char;
begin
  Result := CallNextHookEx(MainHook,wParam,lParam);
  if nCode >= 0 then begin
    GetClassName(PCWPStruct(lParam).hwnd,256);
    if lpClassName = 'TForm1' then
      TFile.AppendAllText('C:Delphilog.txt','WndProc ' +
          IntToStr(PCWPStruct(lParam).message) + sLineBreak);
  end;
end;

procedure InitLog; stdcall;
begin
  MainHook := SetWindowsHookEx(WH_CALLWNDPROC,GetCurrentThreadId);
end;