delphi 在XP/2K 下实现 Win+Ctrl+Del 等键的屏蔽的方法

{*******************************************************************************

XOtecExpress Visual Component Library [陆岛工作室]

By: PengJunLi Build: 2008-06

E-mail: iinsnian@126.com XOtec@vip.QQ.com QQ:442801172

*******************************************************************************}

unit Unit2;

interface

uses

Windows, Messages, SysUtils, Variants, Classes;

type

tagKBDLLHOOKSTRUCT = packed record

vkCode: DWORD;

ScanCode: DWORD;

Flags: DWORD;

Time: DWORD;

dwExtraInfo: DWORD;

end;

KBDLLHOOKSTRUCT = tagKBDLLHOOKSTRUCT;

PKBDLLHOOKSTRUCT = ^KBDLLHOOKSTRUCT;

const

WH_KEYBOARD_LL = 13;

LLKHF_ALTDOWN = $20;

//采用钩子的方法屏蔽系统按键

function DisableTaskKeys(Disable: Boolean): Boolean;

implementation

var

hhkLowLevelKybd: HHOOK;

{ LowLevelKeyboardProc }

function LowLevelKeyboardProc(nCode: Integer; WParam: WPARAM; LParam: LPARAM): LRESULT; stdcall;

var

fEatKeystroke: BOOL;

p: PKBDLLHOOKSTRUCT;

begin

Result := 0;

fEatKeystroke := FALSE;

p := PKBDLLHOOKSTRUCT (lParam);

if (nCode = HC_ACTION) then //nCode值为HC_ACTION时表示WParam和LParam参数包涵了按键消息

begin

//拦截按键消息并测试是否是Ctrl+Esc、Alt+Tab、和Alt+Esc功能键。

case wParam of

WM_KEYDOWN, WM_SYSKEYDOWN, WM_KEYUP, WM_SYSKEYUP:

fEatKeystroke :=

((p.vkCode = VK_TAB) and ((p.flags and LLKHF_ALTDOWN) <> 0)) or // Alt+Tab

((p.vkCode = VK_ESCAPE) and ((p.flags and LLKHF_ALTDOWN) <> 0))or //

(p.vkCode = VK_Lwin) or (p.vkCode = VK_Rwin) or (p.vkCode = VK_apps) or //屏蔽WIN按键

((p.vkCode = VK_ESCAPE) and ((GetKeyState(VK_CONTROL) and $8000) <> 0)) or

((p.vkCode = VK_F4) and ((p.flags and LLKHF_ALTDOWN) <> 0)) or

((p.vkCode = VK_SPACE) and ((p.flags and LLKHF_ALTDOWN) <> 0)) OR

(((p.vkCode = VK_CONTROL) and (P.vkCode = LLKHF_ALTDOWN and p.flags) and (P.vkCode = VK_Delete)));

end;

if fEatKeystroke = True then

Result := 1;

if nCode <> 0 then

Result := CallNextHookEx(0, nCode, wParam, lParam);

end;

{ DisableTaskKeys }

function DisableTaskKeys(Disable: Boolean): Boolean;

begin

Result := False;

if (hhkLowLevelKybd = 0) and Disable then

begin

hhkLowLevelKybd :=SetWindowsHookExW(WH_KEYBOARD_LL, LowLevelKeyboardProc, Hinstance, 0); //设置钩子

Result := hhkLowLevelKybd<>0; // 返回设置成功

end else if not Disable and (hhkLowLevelKybd<>0) then

begin

if UnhookWindowsHookEx(hhkLowLevelKybd) then //卸载键盘钩子

begin

Result := True;

hhkLowLevelKybd := 0;

end;

end.

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