C# Winform 制作可任意拖动的不规则背景图片窗体

public partial class frmPlayer : Form
{
   private Point _MouseOffset;
   private bool _IsMouseDown = false;
   
   public frmPlayer()
   {
      InitializeComponent();
   }
   //如转载请注明出处，本文来自C/S框架网 www.csframework.com
   private void menuClose_Click(object sender, EventArgs e)
   {
      Application.Exit();
   }
   private void frmLogin_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 frmLogin_MouseMove(object sender, MouseEventArgs e)
   {
      if (_IsMouseDown)
      {
         Point mousePos = Control.MousePosition;
         mousePos.Offset(_MouseOffset.X, _MouseOffset.Y);
         Location = mousePos;
      }
   }
   
   private void frmLogin_MouseUp(object sender, MouseEventArgs e)
   {
      if (e.Button == MouseButtons.Left)
      {
         _IsMouseDown = false;
      }
   }
   
}