hook调用

Question

dll文件
library GMousehook;uses
  SysUtils,wintypes,winprocs,messages,windows, Dialogs, mousehookdemou,
  Classes;
var
  ishooked:boolean;
  hookhandle:hhook;
  desktopwin:hwnd;
  OldProc:FARPROC;function hookproc(code:integer;wparam:wparam;lparam:lparam):lresult;stdcall;
var
WinStr:HWND;
begin
  if wparam=WM_LBUTTONDBLCLK then
  begin
  showmessage('鼠标左键双击');
  end;
  result:=callnexthookex(hookhandle,code,wparam,lparam);
end;function sethook:boolean;stdcall;
begin
result:=false;
if ishooked then
exit;
//desktopwin:=getdesktopwindow;
hookhandle:=setwindowshookex(wh_mouse,hookproc,hinstance,0);
ishooked:=true;
result:=hookhandle<>0;
end;function removehook:boolean;stdcall;
begin
result:=false;
if (not ishooked) and (hookhandle<>0) then
result:=unhookwindowshookex(hookhandle);
ishooked:=false;
end;
exports
  sethook name 'sethook',
  removehook name 'removehook',
  hookproc name 'hookproc';{$R *.res}
begin
  ishooked:=false;
end.主程序：
unit mousehookdemou;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public    { Public declarations }
  end;
  function sethook:boolean;stdcall;
  function removehook:boolean;stdcall;
var
  Form1: TForm1;
  s:string;
implementation
   function sethook;external 'gmousehook.dll' name 'sethook';
   function removehook;external 'gmousehook.dll' name 'removehook';
   
{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
 if sethook then
 showmessage('global mouse hook set, click on desktop ')
 else
 showmessage('global mouse hook not set');
 
end;procedure TForm1.Button2Click(Sender: TObject);
begin
if removehook then
 showmessage('global mouse hook removed,click on desktop')
 else
 showmessage('global mouse hook not removed');
end;procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
showmessage(s);
end;
end.
问题是主程序中如何知道有鼠标左键双击呢，在主程序中添加一个字符串变量dll文件可以调用吗？

Answer 1

const CUSTOM_LBUTTONDBLCLK = WM_USER + 100;
为 sethook 增加一个参数，把主窗口句柄传进去
function sethook(mainwnd: Cardinal):boolean;stdcall; 
begin
  FMainWnd := mainwnd;
  // other code
end;在钩子的回调中function hookproc(code:integer;wparam:wparam;lparam:lparam):lresult;stdcall;
var
WinStr:HWND;
begin
  if wparam=WM_LBUTTONDBLCLK then
  begin
    //showmessage('鼠标左键双击');
    PostMessage(FMainWnd, CUSTOM_LBUTTONDBLCLK, wparam, lparam);
  end;
  result:=callnexthookex(hookhandle,code,wparam,lparam);
end; 
主程序：
unit mousehookdemou;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure OnCustomeLButtonDblClick(var msg: TMessage); message CUSTOM_LBUTTONDBLCLK;
  private
    { Private declarations }
  public    { Public declarations }
  end;
  function sethook:boolean;stdcall;
  function removehook:boolean;stdcall;
var
  Form1: TForm1;
  s:string;
implementation
  function sethook;external 'gmousehook.dll' name 'sethook';
  function removehook;external 'gmousehook.dll' name 'removehook'; procedure TForm1.OnCustomeLButtonDblClick(var msg: TMessage);
begin
  ShowMessage('mouse hook get lbuttondblclick!');
end;