1 library myHook;
 2 
 3 uses
 4   System.SysUtils,
 5   Inifiles,
 6   System.Classes,
 7   Messages,  {消息 WM_LBUTTONDOWN 定义在 Messages 单元}
 8   windows; {钩子函数都来自 Windows 单元}
 9 
10 {$R *.res}
11 
12 var
13   hook:HHOOK;
14 
15 function hookCallBack(nCode:Integer;wParam:WPARAM;lParam:LPARAM):LRESULT;stdcall;
16 var
17   me:CWPSTRUCT;//CallWndProc 缩写
18 begin
19     //處理
20     MessageBox(0,PCHAR(inttostr(wparam)),'提示',MB_OK);
21     Result:=CallNextHookEx(hook,nCode,wParam,lParam);
22 end;
23 
24 
25 function setHook:Boolean;stdcall;
26 begin
27   hook:=SetWindowsHookEx(WH_KEYBOARD,@hookCallBack,HInstance,0);
28   Result:=hook<>0;
29 end;
30 
31 function deleteHook:boolean;stdcall;
32 begin
33   result:=UnhookWindowsHookEx(hook);
34 end;
35 
36 {按 DLL 的要求输出函数}
37 exports
38   setHook name 'setHook',
39   deleteHook name 'deleteHook',
40   hookCallBack name 'hookCallBack';
41 begin
42 end.

 1 unit Unit5;
 2 
 3 interface
 4 
 5 uses
 6   Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
 7   Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;
 8 
 9 type
10   TForm5 = class(TForm)
11     Button1: TButton;
12     Button2: TButton;
13     procedure Button1Click(Sender: TObject);
14     procedure Button2Click(Sender: TObject);
15   private
16     { Private declarations }
17   public
18     { Public declarations }
19   end;
20 
21 var
22   Form5: TForm5;
23 
24 implementation
25 
26 {$R *.dfm}
27   {要先要定义和 DLL 中同样参数和返回值的的函数类型}
28 type
29   TDLLFun = function: Boolean; stdcall;
30   {现在需要的 DLL 中的函数的格式都是这样, 定义一个就够了}
31 var
32  h: HWND;                   {声明一个 DLL 句柄}
33  SetHook, DelHook: TDLLFun; {声明两个 TDLLFun 变量}
34 
35 
36 procedure TForm5.Button1Click(Sender: TObject);
37 var
38  b:Boolean;
39 begin
40   h := LoadLibrary('myHook.dll'); {载入 DLL 并获取句柄}
41   if h<>0 then
42   begin
43     SetHook := GetProcAddress(h, 'setHook'); {让 SetHook 指向 DLL 中相应的函数}
44     DelHook := GetProcAddress(h, 'deleteHook'); {让 DelHook 指向 DLL 中相应的函数}
45   end else ShowMessage('Err');
46   b:=SetHook; {执行钩子建立函数, 这里的 SetHook 和它指向的函数是同名的, 也可以不同名}
47 end;
48 
49 procedure TForm5.Button2Click(Sender: TObject);
50 begin
51   DelHook;        {执行钩子释放函数}
52   FreeLibrary(h); {释放 DLL 资源}
53 end;
54 
55 end.