基于C#实现电脑系统挂机锁

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    private Point mouseOffset;//鼠标位置
    private bool isMouseDown = false;//表示鼠标是否按下
    private void pictureBox2_Click(object sender, EventArgs e)
    {
        Application.Exit();//窗体的关闭按钮
    }

    private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {
        int xOffset;
        int yOffset;
        if (e.Button == MouseButtons.Left)
        {
            xOffset = -e.X;
            yOffset = -e.Y;
            mouseOffset = new Point(xOffset, yOffset);
            isMouseDown = true;
        }
    }

    private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
    {
        if (isMouseDown)
        {
            Point mousePos = Control.MousePosition;
            mousePos.Offset(mouseOffset.X, mouseOffset.Y);
            Location = mousePos;
        }
    }

    private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            isMouseDown = false;
        }
    }

    private void button2_Click(object sender, EventArgs e)
    {
        Application.Exit();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        if (txtPwd.Text.Trim() == "" || txtPwd2.Text.Trim() == "")//判断是否输入密码
        {
            MessageBox.Show("请输入密码！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
        else
        {
            if (txtPwd2.Text.Trim() == txtPwd.Text.Trim())//如果两次密码输入一致
            {
                Form2 frm2 = new Form2();//实例化Form2窗体
                frm2.s = this.Size;//传递窗体大小
                frm2.x = this.Location.X;//传递窗体的X坐标
                frm2.y = this.Location.Y;//传递窗体的Y坐标
                frm2.infos = txtInfo.Text.Trim();//传递挂机信息
                frm2.pwd = txtPwd2.Text.Trim();//传递解锁密码
                this.Hide();//隐藏当前窗体
                frm2.ShowDialog();//打开Form2窗体
            }
            else
            {
                MessageBox.Show("两次密码不一致！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }
        }
    }

    private void Form1_Load(object sender, EventArgs e)
    {

    }
}

public partial class Form2 : Form
{
    public Form2()
    {
        InitializeComponent();
    }
    public Size s;//获取鼠标活动的区域
    public int x;//获取鼠标活动区域的X坐标
    public int y;//获取鼠标活动区域的Y坐标
    public string infos;//获取挂机信息
    public string pwd;//获取解锁密码
    myHook h = new myHook();//实例化公共类
    private void Form2_Load(object sender, EventArgs e)
    {
        label1.Location = new Point(x,y-50);//设置显示挂机信息的位置
        label1.Text = infos;//显示挂机信息
        base.Opacity = 0.5;//设置挂机界面透明度
        h.InsertHook();//安装钩子
    }

    private void Form2_MouseMove(object sender, MouseEventArgs e)
    {
        Cursor.Clip = new Rectangle(x, y, s.Width, s.Height);//设置鼠标活动的区域
    }

    private void Form2_MouseClick(object sender, MouseEventArgs e)
    {
        Form3 frm3 = new Form3();//实例化Form3窗体
        frm3.x = x;//传递X坐标
        frm3.y = y;//传递Y坐标
        frm3.infos = infos;//传递挂机信息
        frm3.pwd = pwd;//传递解锁密码
        frm3.ShowDialog();//打开解锁界面
    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        Process[] p = Process.GetProcesses();//获取所有系统运行的进程
        foreach (Process p1 in p)//遍历进程
        {
            try
            {
                //如果进程中存在名为“taskmgr”，则说明任务管理器已经打开   
                if (p1.ProcessName.ToLower().Trim() == "taskmgr")
                {
                    p1.Kill();//关掉任务管理器的进程
                    Cursor.Clip = new Rectangle(x, y, s.Width, s.Height);//重新设置鼠标活动的区域
                    return;
                }
            }
            catch
            {
                return;
            }
        }
    }

    private void Form2_FormClosing(object sender, FormClosingEventArgs e)
    {
        h.UnInsertHook();//卸载钩子
        timer1.Stop();//停止计时器
    }
}

public partial class Form3 : Form
{
    public Form3()
    {
        InitializeComponent();
    }
    public int x;//鼠标活动区域的X坐标
    public int y;//鼠标活动区域的Y坐标
    public string infos;//挂机界面显示的信息
    public string pwd;//解锁密码
    private void Form3_Load(object sender, EventArgs e)
    {
        this.TopMost = true;//设置停靠在最前端
        this.Location = new Point(x, y);//设置窗体位置
        lblinfo.Text = infos;//显示挂机信息
    }

    private void button1_Click(object sender, EventArgs e)
    {
        if (txtPwd.Text.Trim() == pwd)//判断输入的密码是否正确
        {
            Application.Exit();//如果正确则退出挂机界面
        }
        else//否则
        {
            lblinfo.Text = "输入解锁密码错误，请重新输入！";//提示错误信息
        }
    }

    private void button2_Click(object sender, EventArgs e)
    {
        this.TopMost = false;//取消停靠最前的设置
        this.Close();//关闭窗体
    }
}

public class myHook
{
    private IntPtr pKeyboardHook = IntPtr.Zero;//键盘钩子句柄
    public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);// 钩子委托声明
    //键盘钩子委托实例不能省略变量
    private HookProc KeyboardHookProcedure;
    //底层键盘钩子
    public const int idHook = 13;
    //安装钩子
    [DllImport("user32.dll", CallingConvention = CallingConvention.StdCall)]
    public static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn,
        IntPtr pInstance, int threadId);
    //卸载钩子
    [DllImport("user32.dll", CallingConvention = CallingConvention.StdCall)]
    public static extern bool UnhookWindowsHookEx(IntPtr pHookHandle);
    //键盘钩子处理函数
    private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
    {
        KeyMSG m = (KeyMSG)Marshal.PtrToStructure(lParam, typeof(KeyMSG));
        if (pKeyboardHook != IntPtr.Zero)
        {
            switch (((Keys)m.vkCode))
            {
                case Keys.LWin:
                case Keys.RWin:
                case Keys.Delete:
                case Keys.Alt:
                case Keys.Escape:
                case Keys.F4:
                case Keys.Control:
                case Keys.Tab:
                    return 1;
            }
        }
        return 0;
    }
    //安装钩子
    public bool InsertHook()
    {
        IntPtr pIn = (IntPtr)4194304;
        if (this.pKeyboardHook == IntPtr.Zero)
        {
            this.KeyboardHookProcedure = new HookProc(KeyboardHookProc);
            this.pKeyboardHook = SetWindowsHookEx(idHook, KeyboardHookProcedure, pIn, 0);
            if (this.pKeyboardHook == IntPtr.Zero)
            {
                this.UnInsertHook();
                return false;
            }
        }

        return true;
    }
    //卸载钩子
    public bool UnInsertHook()
    {
        bool result = true;
        if (this.pKeyboardHook != IntPtr.Zero)
        {
            result = (UnhookWindowsHookEx(this.pKeyboardHook) && result);
            this.pKeyboardHook = IntPtr.Zero;
        }
        return result;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct KeyMSG
    {
        public int vkCode;
        public int scanCode;
        public int flags;
        public int time;
        public int dwExtraInfo;
    }
}