请教：一个搞了我两天的全全局系统钩子问题

Question

我的目的是写一个系统钩子（全局的），便现在发现只有激活调用程序（调用程序获取到焦点）才捉到事件，请问是为什么？

Answer 1

library hook;uses
  SysUtils,
  Classes,
  HookUnit in 'HookUnit.pas';
exports
  EnableHotKeyHook,
  DisableHotKeyHook;
{$R *.res}begin
  hNextHookProc := 0;
  procSaveExit := ExitProc;
  ExitProc := @HotKeyHookExit;
  
  MouseNextProc:=0;
  MouseSaveExit:=ExitProc;
  ExitProc:=@MouseHookExit;
end.
/////////////////////////////////////////////////////////////////////////
unit HookUnit;interface
uses Windows, Messages,Dialogs,SysUtils,registry,DateUtils;var
  hNextHookProc: HHook; //保存SetWindowsHookEx的返回值
  procSaveExit: Pointer;
  LastTime:string;  MouseNextProc:HHook;
  MouseSaveExit:Pointer;
function KeyboardHookHandler(iCode: Integer; wParam: WPARAM; lParam: LPARAM): LRESULT;
procedure HotKeyHookExit; far;function MouseHookHandler(iCode: Integer; wParam: WPARAM; lParam: LPARAM): LRESULT;
procedure MouseHookExit; far;procedure WriteReg;function EnableHotKeyHook: BOOL; stdcall; //安装钩子
function DisableHotKeyHook: BOOL; stdcall; //卸载钩子implementationprocedure WriteReg;
var
  reg: TRegistry;
begin
  //每十秒写一次
  if abs(SecondsBetween(now, strtodatetime(LastTime)))>10 then
  begin
    reg := TRegistry.Create;
    reg.RootKey := HKEY_LOCAL_MACHINE;
    if reg.OpenKey('SOFTWARE\BSQs', true) then
      reg.WriteString('PointTime', datetimetostr(now));
    reg.CloseKey;
    reg.Free;
    LastTime:=datetimetostr(now);
  end;
end;function KeyboardHookHandler(iCode: Integer; wParam: WPARAM; lParam: LPARAM): LRESULT; stdcall;export;begin
  try
    WriteReg;
    Result:=CallNextHookEx(hNextHookProc, iCode, wParam, lParam);
  except
    Result:=CallNextHookEx(hNextHookProc, iCode, wParam, lParam);
  end;
end;function MouseHookHandler(iCode: Integer; wParam: WPARAM; lParam: LPARAM): LRESULT; stdcall;export;
begin
  try
    WriteReg;
    Result:=CallNextHookEx(MouseNextProc, iCode, wParam, lParam);
  except
    Result:=CallNextHookEx(MouseNextProc, iCode, wParam, lParam);
  end;
end;function EnableHotKeyHook: BOOL;
begin
  try
    Result := False; //初始化返回值
    LastTime:=datetimetostr(now);
    //注册hook
    if not hNextHookProc <> 0 then //如果没有注册，挂上键盘钩子,同时传回值必须保留下来,免得Hook呼叫链结断掉
      hNextHookProc := SetWindowsHookEx(WH_KEYBOARD, KeyboardHookHandler, HInstance, 0);
    if not MouseNextProc <>0 then
      MouseNextProc:= SetWindowsHookEx(WH_MOUSE, MouseHookHandler, HInstance, 0);
    Result := MouseNextProc <> 0; //通过返回值确定是否注册成功
  except  end;
end;function DisableHotKeyHook: BOOL;
begin
  try
    if MouseNextProc <> 0 then
    begin
      UnhookWindowshookEx(hNextHookProc); //解除Keyboard Hook
      hNextHookProc := 0; //恢复标志      UnhookWindowshookEx(MouseNextProc);
      MouseNextProc:=0;
    end;
    Result := MouseNextProc = 0; //返回是否注销成功
  except  end;
end;procedure HotKeyHookExit;
begin
  if MouseNextProc <> 0 then DisableHotKeyHook; //如果忘了解除HOOK,自动代理解除动作
  ExitProc := MouseSaveExit;
end;procedure MouseHookExit;
begin
  if MouseNextProc<>0 then  DisableHotKeyHook;
  ExitProc :=MouseSaveExit;
end;
end.