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dll   代码

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library keyHook;

uses   System.SysUtils,   System.Classes,   Unit4 in 'Unit4.pas'; {$R *.res} begin end.

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unit Unit4;

interface uses   System.SysUtils,   Windows,   System.Classes; const   BUFFER_SIZE=16*1024;   HOOK_MEM_FILENAME='MEM_FILE';   HOOK_MUTEX_NAME='MUTEX_NAME'; type   tshared=record     keys:array [0..BUFFER_SIZE] of    char;     keycount:integer;   end;   PSHared=^tshared; var   memfile,hookmutex:thandle;   holdkeyhook:HHook;   shared:pshared; implementation //键盘钩子 function keyHookProc(icode:integer;wparam:WPARAM;lparam:LPARAM):LRESULT;stdcall;export; const   keypressmask=$80000000; begin   if icode<0 then     result:=callnexthookex(holdkeyhook,icode,wparam,lparam)   else  begin     if ((lparam and keypressmask)=0) then//键按下     begin        shared^.keys[shared^.keycount]:=char(wparam and $00ff);        inc(shared^.keycount);        if shared^.keycount>=BUFFER_SIZE-1 then           shared^.keycount:=0;     end;     result:=0;   end; end; //设置钩子 function EnableKeyHook:bool;export; begin   shared^.keycount:=0;   if holdkeyhook=0 then   begin      holdkeyhook:= SetWindowsHookex(WH_KEYBOARD,keyHookProc,hinstance,0);   end;   result:= (holdkeyhook<>0); end; //卸载钩子 function DisableKeyHook:bool;export; begin   if  holdkeyhook<>0 then   begin     unhookwindowshookex(holdkeyhook);     //解除     holdkeyhook :=0;     shared^.keycount:=0;   end;   result:=(holdkeyhook<>0); end; //获取缓存区数据长度 function GetKeyCount:integer ; export; begin   result:=shared^.keycount; end; //清除键盘缓冲区 procedure cleankeyStr;export; begin   shared^.keycount:=0; end; //取得键值 function getKeyValuex(index:integer):char;export; begin   result:=shared^.keys[index]; end; exports   EnableKeyHook,   DisableKeyHook,   GetKeyCount,   getKeyValuex,   cleankeyStr; initialization   hookmutex:=createmutex(nil,true,hook_mutex_name);   //打开内存映像   memfile:=openfileMapping(FILE_MAP_WRITE,false,HOOK_MEM_FILENAME);   if memfile=0 then   //打开失败时就建立     memfile:=createfilemapping($ffffffff,nil,PAGE_READWRITE,0,sizeof(tshared),HOOK_MEM_FILENAME);   shared:=mapviewoffile(memfile,FILE_MAP_WRITE,0,0,0);   releaseMutex(hookmutex);   closeHandle(hookmutex); finalization   if holdkeyhook<>0 then   disableKeyHook;   unmapviewoffile(shared);//释放映像文件   closehandle(memfile); end.

-------------------------------------测试dll的代码-----

unit Unit5;

interface uses   Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,   Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls; type   TForm5 = class(TForm)     btn_sethook: TButton;     btn_canelhook: TButton;     btn_readkey: TButton;     btn_clearkey: TButton;     Label1: TLabel;     Memo1: TMemo;     procedure btn_sethookClick(Sender: TObject);     procedure btn_canelhookClick(Sender: TObject);     procedure btn_readkeyClick(Sender: TObject);     procedure btn_clearkeyClick(Sender: TObject);     procedure FormCreate(Sender: TObject);   private     { Private declarations }   public     { Public declarations }   end; var   Form5: TForm5; implementation {$R *.dfm} function   EnableKeyHook : bool ; external 'D:\Documents\RAD Studio\Projects\Win32\Debug\keyHook.dll'; function  DisableKeyHook : bool ; external 'D:\Documents\RAD Studio\Projects\Win32\Debug\keyHook.dll'; function  GetKeyCount : integer ; external 'D:\Documents\RAD Studio\Projects\Win32\Debug\keyHook.dll'; function  getKeyValuex(i:integer) : char ; external  'D:\Documents\RAD Studio\Projects\Win32\Debug\keyHook.dll'; procedure  cleankeyStr;         external 'D:\Documents\RAD Studio\Projects\Win32\Debug\keyHook.dll'; procedure TForm5.btn_canelhookClick(Sender: TObject); begin   DisableKeyHook;   btn_canelhook.Enabled:=false;   btn_sethook.Enabled:=true;    btn_readkey.Enabled:=false;    btn_clearkey.Enabled:=false;    Label1.Caption:='键盘钩子已经取消'; end; procedure TForm5.btn_clearkeyClick(Sender: TObject); begin   memo1.Clear;   cleankeyStr; end; procedure TForm5.btn_readkeyClick(Sender: TObject); var   i:integer; begin   memo1.Lines.Clear;   for i := 0 to GetKeyCount-1 do     memo1.Text:=memo1.Text+getKeyValuex(i); end; procedure TForm5.btn_sethookClick(Sender: TObject); begin    EnableKeyHook;    btn_sethook.Enabled:=false;    btn_canelhook.Enabled:=true;    btn_readkey.Enabled:=true;    btn_clearkey.Enabled:=true;    Label1.Caption:='键盘钩子已经设置好了'; end; procedure TForm5.FormCreate(Sender: TObject); begin end; end.

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