C#实现将窗体固定在显示器的左上角且不能移动的方法

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.IO;using System.Runtime.InteropServices;namespace App{ public partial class Form4 : Form {  public Form4()  {   InitializeComponent();   this.StartPosition = FormStartPosition.Manual;   this.Location = new Point(0, 0);  }  protected override void WndProc(ref Message m)  {   base.WndProc(ref m);   if (m.Msg == 0x84 && m.Result == (IntPtr)2) //不让拖动标题栏    {    m.Result = (IntPtr)1;   }   if (m.Msg == 0xA3) //双击标题栏无反应    {    m.WParam = System.IntPtr.Zero;   }  } }}