要实现对双击左CTRL键的监控，必须玩钩子了。
代码很简单，新建VCL Form的工程，在窗体上放两个按钮，分别叫做 btnHook 和 btnUnHook。
java获取某个文件夹下的所有文件，调用就是 BeginHook 和 EndHook 这两个函数，窗体代码如下：
unit frmTestHookWinKey;interfaceusesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls, ShellAPI;typeTForm1 = class(TForm)btnHook: TButton;btnUnHook: TButton;procedure btnHookClick(Sender: TObject);procedure btnUnHookClick(Sender: TObject);procedure FormCreate(Sender: TObject);private{ Private declarations }public{ Public declarations }end;varForm1: TForm1;implementation{$R *.dfm}varKeyHook: HHook;HitTime: Cardinal; // 击键的间隔时间HitThreshold: Integer; // 击键的间隔时间门限function HookKey(Code: integer; wParam: wParam; lParam: lParam): LRESULT; stdcall;
typePKBDLLHOOKSTRUCT = ^KBDLLHOOKSTRUCT;KBDLLHOOKSTRUCT = recordvkCode: DWORD;ScanCode: DWORD;Flags: DWORD;Time: DWORD;dwExtraInfo: DWORD;end;
begin// 如果左 CTRL 键按下if (Code = HC_ACTION) and (PKBDLLHOOKSTRUCT(lParam).vkCode = VK_LCONTROL) and (wParam = WM_KEYDOWN) then beginif HitTime > 0 then beginHitTime := GetTickCount - HitTime; // 取得间隔时间if HitTime <= HitThreshold then begin // 如果间隔时间在门限时间之内，则调用记事本WinExec('notepad.exe', SW_SHOWNORMAL);HitTime := 0;endelseHitTime := GetTickCount;endelseHitTime := GetTickCount;end;Result := CallNextHookEx(KeyHook, Code, wParam, lParam);
end;procedure BeginHook;
beginKeyHook := SetWindowsHookEx(13 {=WH_KEYBOARD_LL}, @HookKey, HInstance, 0);
end;procedure EndHook;
beginUnhookWindowsHookEx(KeyHook);
end;procedure TForm1.btnHookClick(Sender: TObject);
beginBeginHook;
end;procedure TForm1.btnUnHookClick(Sender: TObject);
beginEndHook;
end;procedure TForm1.FormCreate(Sender: TObject);
beginHitTime := 0;HitThreshold := 200; // 200 ms
end;end.既然调用记事本都搞定了，干些其他的事儿自然不在话下了。
这段代码完全可以封装为一个模块，将监控的按键、间隔时间及回调函数当作参数传入即可。
Technorati 标签: Delphi,Hook,CTRL
