library 系统钩子;
uses
System.SysUtils,
windows,
System.Classes;
{$R *.res}
var //定义全局变量
hHook:integer;
function HookProc(iCode: Integer; //处理系统钩子的函数
wParam: WPARAM;
lParam: LPARAM): LRESULT; stdcall; export; //书写调用规则,记得加 stdcall
begin
Result := 0;//注意返回值必须为0,允许对窗口的操作
try
if iCode = HCBT_DESTROYWND then begin//捕获关闭窗口的消息
Winexec('notepad.exe',SW_SHOW); //预处理消息前执行的代码 ,可自定义
end;
except
end;
end;
procedure LoadDestroyWndHook; //设置系统挂钩
begin
hHook:=SetWindowsHookEx(WH_CBT,HookProc,Hinstance,0); //[Error] HookMsg.dpr(65): Incompatible types: 'Calling conventions differ'
end; //函数呼叫约定不一致-->出错
procedure UnLoadDestroyWndHook; //注销系统挂钩
begin
UnHookWindowsHookEx(hHook);
hHook := 0;
end;
exports //输出函数
LoadDestroyWndHook,
UnLoadDestroyWndHook;
begin
end.
调用钩子
function LoadDestroyWndHook: BOOL; external 'HookMsg.dll';
function UnLoadDestroyWndHook: BOOL; external 'HookMsg.dll';
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
UnLoadDestroyWndHook;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
LoadDestroyWndHook;