鼠标钩子详解

来源：互联网发布：淘宝咸鱼会不会被骗编辑：程序博客网时间：2024/05/22 10:22

钩的作用非常大,它能够预演和修改系统事件和消息,关能在系统范围内阻止事件和消息发生.Windows系统支持多种不同类型的钩,每种类型都只监控一种Windows消息流,下面是几种常见钩类型.

WH_MOUSE 监控鼠标输入事件

WH_KEYBOARD 监控键盘输入事件

WH_CALLWNDPROC 监控发送到窗口过程的消息,钩过程在消息发送到窗口过程前调用

WH_CALLWNDPROCRET监控发送到窗口过程的消息,钩过程在消息发送到窗口过程后调用

WH_CBT 监控CBT(如窗口创建,最大最小化等计算机使用培训相关的)消息

WH_SHEEL 监控Windows外壳通知消息,例如创建释放顶级窗口

等等….

为了使某种类型的钩发生作用,钩过程必须满足一定的语法条件,使用Win32 API 函数SetWindowsHookEx 来安装到钩链中.SetWindowsHookEx 函数具体定义为:

function SetWindowsHookEx(idHook: Integer; lpfn: TFNHookProc; hmod: HINST; dwThreadId: DWORD): HHOOK; stdcall;

上述声明中,参数idHook 为钩过程类型, lpfn 参数为指向钩过程的指针, hmod 参数表示包含钩过程的DLL 的实例句柄, dwThreadId 参数表示钩过程要监控的线程,如果其值为0则表示将监控系统中的所有线程,如果SetWindowsHookEx 函数调用成功,则返回钩过程的句柄,否则为0;例如:

SetWindowsHookEx(WH_MOUSE,HookHander,Hinstance,0); //HookHander为钩过程

按照Delphi 的定义,所有钩过程都必须采用下述声明规范:

type

TFNHookProc = function (code: Integer; wparam: WPARAM; lparam: LPARAM): LRESULT stdall;

Code 参数表示钩码, 其值取决钩过程的类型,钩过程需要使用该参数确定调用什么样的系统功能,wparam参灵符与iparam参数与code参数有关,通常用于保存已发送或投递消息信息.

SetWindowsHookEx 函数习惯将新钩子到钩链的开头,当某种系统事件或消息发生时,该类型钩链中钩过程将依次获得该事件或消息的处理权,其中每个钩过程独立确定是否将该消息传到下一个钩过程,如果需要,则必须调用Win32 API 函数 CallNextHookEx.

注意在应用程序终止前必须调用 UnhookWindowsHookEx函数释放钩占用的系统资源,就是常说的脱钩啦….呵呵.

好了,我们现在就开始写一个鼠标钩子.获取所有进程的鼠标消息,需要用到系统钩子,所以要用到 DLL 才能截取,因此挂钩函数封装在 DLL 动态链接库中.

首先我们定义钩的数据结构

TShareMInfo = record

DataFirst: array[1..2] of DWORD;

DataMouseInfo: TmouseHookStruct;

End;

PshareMInfo = ^ TshareMInfo;

定义钩过程

function HookHandler(iCode: Integer; wParam: WPARAM; lParam: LPARAM); stdcall;

定义安装钩和脱钩函数

function StartHook(Sender: HWND; MessageID: WORD): BOOL; stdcall;

function StopHook: BOOL; stdcall;

详细代码如下:

unit HookDllUnit;

interface

uses Windows, Messages, Dialogs, SysUtils.

const

MappingFileName='_SelfDllMouse';

TShareMInfo = record

DataFirst: array[1..2] of DWORD; // DataFirst[1] 为窗口句柄,DataFirst[2] 为消息

DataMouseInfo: TmouseHookStruct; //鼠标消息结构

End;

Var

PShMem: PShareMem;

hMappingFile: THandle;

FirstProcess: Boolean;

NextHook: HHook;

function StartHook(Sender: HWND; MessageID: WORD): BOOL; stdcall;

function StopHook: BOOL; stdcall;

implementation

function HookHandler(iCode: Integer; wParam: WPARAM; lParam: LPARAM): LRESULT; stdcall; export;

begin

Result := 0;

if iCode < 0 then

Result := CallNextHookEx(NextHook,ICode,wParam,lParam);

case wParam of

WM_NCMOUSEMOVE, WM_MOUSEMOVE:

begin

PShMem^.DataTwo := PMOUSEHOOKSTRUCT(lParam)^;

SendMessage(PShMem^.DataFirst[1],PShMem^.DataFirst[2],wParam,

integer(@(PShMem^.DataTwo)));

end;

function StartHook(Sender: HWND; MessageID: WORD): BOOL; stdcall;

begin

Result := False;

if NextHook <> 0 then Exit;

PShMem^.DataFirst[1] := Sender;

PShMem^.DataFirst[2] := MessageID;

NextHook := SetWindowsHookEx(WH_MOUSE,HookHandler,HInstance,0);

Result := NextHook <> 0;

end;

function StopHook: BOOL; stdcall;

begin

if NextHook <> 0 then

begin

UnHookWindowsHookEx(NextHook);

NextHook := 0;

end;

Result := NextHook = 0;

end;

initialization //下列为内存映像文件来共享数据(也就是鼠标信息),这里不详细讲了

hMappingFile := OpenFileMapping(FILE_MAP_WRITE,False,MappingFileName);

if hMappingFile = 0 then

begin

hMappingFile := CreateFileMapping($FFFFFFFF,nil,PAGE_READWRITE,0,

SizeOf(TShareMem),MappingFileName);

FirstProcess := True;

end

else FirstProcess := False;

if hMappingFile = 0 then Exception.Create('Don''t Build Share Memory!');

PShMem := MapViewOfFile(hMappingFile,FILE_MAP_WRITE or FILE_MAP_READ,0,0,0);

if PShMem = nil then

begin

CloseHandle(hMappingFile);

Exception.Create('Don''t Mapping Share Memory!');

end;

if FirstProcess then

NextHook := 0;

finalization

UnMapViewOfFile(PShMem);

CloseHandle(hMappingFile);

end.

下面是DLL 代码;

library MouseDll;

uses

SysUtils,

Classes,

HookDllUnit in 'Source/HookDllUnit.pas';

exports

StartHook,StopHook;

begin

end.

下面是主窗口代码:

unit MainForm;

interface

uses

Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

Dialogs, RzButton, StdCtrls , Mask, RzEdit, ExtCtrls, unit HookDllUnit;

type

TForm1 = class(TForm)

Capture: TRzBitBtn;

XYLable: TRzLabel;

procedure CaptureClick(Sender: TObject);

procedure FormClose(Sender: TObject; var Action: TCloseAction);

procedure FormCreate(Sender: TObject);

private

{ Private declarations }

public

{ Public declarations }

procedure WndProc(var Messages: TMessage); override; //接受来自 MouseDLL 发送过来的消息

end;

var

Form1: TForm1;

hMappingFile: THandle;

PShmem: PShareMem;

const MessageID = WM_USER + 211; //自定义消息

implementation

function StartHook(sender : HWND;MessageID : WORD) : BOOL;stdcall; external 'MouseDll.DLL';

function StopHook: BOOL;stdcall; external 'MouseDll.DLL';

{$R *.dfm}

procedure TForm1.CaptureClick(Sender: TObject);

begin

if capture.caption='Start' then

begin

if StartHook(Handle,MessageID) then

capture.caption:='Stop';

end

else begin

if StopHook then

capture.caption:='Start';

end;

procedure TForm1.WndProc(var Messages: TMessage);

var

X,Y: integer;

begin

if PShMem = nil then

begin

hMappingFile := OpenFileMapping(FILE_MAP_WRITE,False,MappingFileName);

if hMappingFile=0 then Exception.Create('Don''t Build Share Memory!');

PShMem := MapViewOfFile(hMappingFile,FILE_MAP_WRITE or FILE_MAP_READ,0,0,0);

if PShMem = nil then

begin

CloseHandle(hMappingFile);

Exception.Create('Don''t Mapping Share Memory!');

end;

// 上面取得DLL 共享数据

end;

if PShMem = nil then Exit;

if Messages.Msg = MessageID then

begin

X := PShMem^.DataTwo.pt.X;

Y := PShMem^.DataTwo.pt.Y;

XYLable.Caption := Format('X: º%d Y : º%d',[X,Y]);

end

else inherited;

end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);

begin

if Capture.Caption = 'Stop' then

else

begin

if StopHook then

Capture.Caption := 'Start';

end;

procedure TForm1.FormCreate(Sender: TObject);

begin

PShMem := nil;

end;

end.

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/GARNETT2183/archive/2005/10/23/514038.aspx