c# 全局鼠标事件

public class Win32Api
    {
        [StructLayout(LayoutKind.Sequential)]
        public class POINT
        {
            public int x;
            public int y;
        }
        [StructLayout(LayoutKind.Sequential)]
        public class MouseHookStruct
        {
            public POINT pt;
            public int hwnd;
            public int wHitTestCode;
            public int dwExtraInfo;
        }
        public delegate int HookProc(int nCode, IntPtr wParam, IntPtr lParam);
        //安装钩子
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
        //卸载钩子
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern bool UnhookWindowsHookEx(int idHook);
        //调用下一个钩子
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int CallNextHookEx(int idHook, int nCode, IntPtr wParam, IntPtr lParam);
    }
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public class MouseHook
    {
        private Point point;
        private Point Point
        {
            get { return point; }
            set
            {
                if (point != value)
                {
                    point = value;
                    if (MouseMoveEvent != null)
                    {
                        var e = new MouseEventArgs(MouseButtons.None, 0, point.X, point.Y, 0);
                        MouseMoveEvent(this, e);
                    }
                }
            }
        }
        private int hHook;
        private static int hMouseHook = 0;
        private const int WM_MOUSEMOVE = 0x200;
        private const int WM_LBUTTONDOWN = 0x201;
        private const int WM_RBUTTONDOWN = 0x204;
        private const int WM_MBUTTONDOWN = 0x207;
        private const int WM_LBUTTONUP = 0x202;
        private const int WM_RBUTTONUP = 0x205;
        private const int WM_MBUTTONUP = 0x208;
        private const int WM_LBUTTONDBLCLK = 0x203;
        private const int WM_RBUTTONDBLCLK = 0x206;
        private const int WM_MBUTTONDBLCLK = 0x209;

        public const int WH_MOUSE_LL = 14;
        public Win32Api.HookProc hProc;
        public MouseHook()
        {
            this.Point = new Point();
        }
        public int SetHook()
        {
            hProc = new Win32Api.HookProc(MouseHookProc);
            hHook = Win32Api.SetWindowsHookEx(WH_MOUSE_LL, hProc, IntPtr.Zero, 0);
            return hHook;
        }
        public void UnHook()
        {
            Win32Api.UnhookWindowsHookEx(hHook);
        }
        private int MouseHookProc(int nCode, IntPtr wParam, IntPtr lParam)
        {
            Win32Api.MouseHookStruct MyMouseHookStruct = (Win32Api.MouseHookStruct)Marshal.PtrToStructure(lParam, typeof(Win32Api.MouseHookStruct));
            if (nCode < 0)
            {
                return Win32Api.CallNextHookEx(hHook, nCode, wParam, lParam);
            }
            else
            {
                MouseButtons button = MouseButtons.None;
                int clickCount = 0;
                switch ((Int32)wParam)
                {
                    case WM_LBUTTONDOWN:
                        button = MouseButtons.Left;
                        clickCount = 1;
                        MouseDownEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        break;
                    case WM_RBUTTONDOWN:
                        button = MouseButtons.Right;
                        clickCount = 1;
                        MouseDownEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        break;
                    case WM_MBUTTONDOWN:
                        button = MouseButtons.Middle;
                        clickCount = 1;
                        MouseDownEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        break;
                    case WM_LBUTTONUP:
                        button = MouseButtons.Left;
                        clickCount = 1;
                        MouseUpEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        break;
                    case WM_RBUTTONUP:
                        button = MouseButtons.Right;
                        clickCount = 1;
                        MouseUpEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        break;
                    case WM_MBUTTONUP:
                        button = MouseButtons.Middle;
                        clickCount = 1;
                        MouseUpEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        break;
                }

                this.Point = new Point(MyMouseHookStruct.pt.x, MyMouseHookStruct.pt.y);
                return Win32Api.CallNextHookEx(hHook, nCode, wParam, lParam);
            }
        }

        public delegate void MouseMoveHandler(object sender, MouseEventArgs e);
        public event MouseMoveHandler MouseMoveEvent;

        public delegate void MouseClickHandler(object sender, MouseEventArgs e);
        public event MouseClickHandler MouseClickEvent;

        public delegate void MouseDownHandler(object sender, MouseEventArgs e);
        public event MouseDownHandler MouseDownEvent;

        public delegate void MouseUpHandler(object sender, MouseEventArgs e);
        public event MouseUpHandler MouseUpEvent;
    }
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MouseHook mh;

        private void Form1_Load(object sender, EventArgs e)
        {
            mh = new MouseHook();
            mh.SetHook();
            mh.MouseDownEvent += mh_MouseDownEvent;
            mh.MouseUpEvent += mh_MouseUpEvent;
        }

        bool LeftTag = false;
        bool RightTag = false;
        Point p1 = new Point(0,0);
        Point p2 = new Point(0, 0);

        //按下鼠标键触发的事件
        private void mh_MouseDownEvent(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                LeftTag = true;
                richTextBox1.AppendText("按下了左键\n");
            }
            if (e.Button == MouseButtons.Right)
            {
                RightTag = true;
                richTextBox1.AppendText("按下了右键\n");
            }
            p1 = e.Location;
        }

        //松开鼠标键触发的事件
        private void mh_MouseUpEvent(object sender, MouseEventArgs e)
        {
            p2 = e.Location;
            double value = Math.Sqrt(Math.Abs(p1.X - p2.X) * Math.Abs(p1.X - p2.X) + Math.Abs(p1.Y - p2.Y) * Math.Abs(p1.Y - p2.Y));
            //if (LeftTag && RightTag && value > 100)
            //{
            //    MessageBox.Show("ok");
            //}
            if (e.Button == MouseButtons.Left)
            {
                richTextBox1.AppendText("松开了左键\n");
            }
            if (e.Button == MouseButtons.Right)
            {
                richTextBox1.AppendText("松开了右键\n");
            }
            richTextBox1.AppendText("移动了" + value + "距离\n");
            RightTag = false;
            LeftTag = false;
            p1 = new Point(0, 0);
            p2 = new Point(0, 0);
        }
        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            mh.UnHook();
        }
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