Qt 屏蔽系统按键、任务管理器、任务栏、鼠标，修改注册表

.h

#ifndef CHOOK_H
#define CHOOK_H

#include <QObject>
#include <Windows.h>

/************************************************************************/
/*   钩子类,屏蔽系统热键
	author: liulihuo
	date : 2017/9/26
*/
/************************************************************************/

class CHook : public QObject
{
	Q_OBJECT

public:
	CHook(QObject *parent = NULL);
	~CHook();
	void hook(bool flag); //功能键
	void showTaskWindow(bool flag); //显示任务栏
	void enableTaskManager(bool flag); //任务管理器
private:
	HWND task;

};

#endif // CHOOK_H

.cpp

#include "chook.h"
#include <QDebug>
#include <QSettings>

//在注册表该目录下增加新内容
#define TASKMANAGERSystem "HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\System"
#define TASKMANAGERExplorer "HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer"

HHOOK keyHook = NULL;
HHOOK mouseHook = NULL;

//键盘钩子过程
LRESULT CALLBACK keyProc(int nCode,WPARAM wParam,LPARAM lParam )
{
	//在WH_KEYBOARD_LL模式下lParam 是指向KBDLLHOOKSTRUCT类型地址
	KBDLLHOOKSTRUCT *pkbhs = (KBDLLHOOKSTRUCT *) lParam;
	//如果nCode等于HC_ACTION则处理该消息，如果小于0，则钩子子程就必须将该消息传递给 CallNextHookEx
	if(nCode == HC_ACTION)
	{
		if((pkbhs->vkCode == VK_ESCAPE && GetAsyncKeyState(VK_CONTROL)& 0x8000 && GetAsyncKeyState(VK_SHIFT)&0x8000)|| //"Ctrl+Shift+Esc"
			(pkbhs->vkCode == VK_ESCAPE && GetAsyncKeyState(VK_CONTROL) & 0x8000) || //"Ctrl+Esc"
			(pkbhs->vkCode == VK_TAB && pkbhs->flags & LLKHF_ALTDOWN )|| //"Alt+Tab"
			(pkbhs->vkCode == VK_ESCAPE && pkbhs->flags &LLKHF_ALTDOWN )|| //"Alt+Esc"
			(pkbhs->vkCode == VK_LWIN || pkbhs->vkCode == VK_RWIN )||	// "LWIN/RWIN"
			(pkbhs->vkCode == VK_F4 && pkbhs->flags & LLKHF_ALTDOWN )) //"Alt+F4"
		{
			return 1;//返回1表示截取消息不再传递,返回0表示不作处理,消息继续传递
		}	

		// 		if(pkbhs->vkCode == VK_F12)
		// 		{
		// 			void unHook();
		// 			qApp->quit();
		// 		}
	}
	return CallNextHookEx(keyHook, nCode, wParam, lParam);
}
//鼠标钩子过程
LRESULT CALLBACK mouseProc(int nCode,WPARAM wParam,LPARAM lParam )
{

	return 1;

}

CHook::CHook(QObject *parent)
: QObject(parent)
{
	
}

CHook::~CHook()
{

}

//安装钩子,调用该函数即安装钩子
void CHook::hook(bool flag)
{
	if (flag)
	{
		//这两个底层钩子,不要DLL就可以全局
		//底层键盘钩子
		keyHook =SetWindowsHookEx( WH_KEYBOARD_LL,keyProc,GetModuleHandle(NULL),0);
		//底层鼠标钩子
		//    mouseHook =SetWindowsHookEx( WH_MOUSE_LL,mouseProc,GetModuleHandle(NULL),0);
	}
	else
	{
		UnhookWindowsHookEx(keyHook);
		//  UnhookWindowsHookEx(mouseHook);
	}
}

//添加注册屏蔽Ctrl+Alt+del
void CHook::enableTaskManager(bool flag)
{
	// 屏蔽ctrl + alt +del 需要修改注册表的值， 取得管理员权限， 关闭360等杀毒软件
	int value = flag ? 0x00000001 : 0x00000000;
	QSettings *settings = new QSettings(TASKMANAGERSystem, QSettings::NativeFormat);
	settings->setValue("DisableTaskMgr", value); //任务管理器
	settings->setValue("DisableChangePassword", value); //更改密码
	settings->setValue("DisableLockWorkstation", value); //锁定计算机
	settings->setValue("DisableSwitchUserOption", value); //切换用户

	QSettings *settings2 = new QSettings(TASKMANAGERExplorer, QSettings::NativeFormat);
	settings2->setValue("NoLogOff", value); //注销

	delete settings;
	delete settings2;
}

//屏蔽任务栏
void CHook::showTaskWindow(bool flag)
{
	if(flag)
		ShowWindow(task,SW_SHOW);
	else
	{
		task=FindWindow(L"Shell_TrayWnd",NULL);
		ShowWindow(task,SW_HIDE);
	}
}