winform创建不规则窗体的方法

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Microsoft.Win32;
using System.Drawing.Drawing2D;
using System.IO;
namespace WindowsApplication2
{
 public partial class Form3 : Form
 {
  public Form3()
  {
   InitializeComponent();
   this.FormBorderStyle = FormBorderStyle.None;
   ColorConverter colorconvert = new ColorConverter();
   this.BackColor = (Color)colorconvert.ConvertFromString("window");
   this.TransparencyKey = (Color)colorconvert.ConvertFromString("window");
  }
  private void button1_Click(object sender, EventArgs e)
  {
   this.Close();
  }
  protected override void OnPaint(PaintEventArgs e)
  {
   Graphics g = e.Graphics;
   Rectangle mainRect = new Rectangle(0, 0, 695, 278);
   Region mainRegion = new Region(mainRect);
   e.Graphics.SetClip(mainRegion, CombineMode.Replace);
   //设置窗体的外观形式
   Point point1 = new Point(0, 32);
   Point point2 = new Point(9, 20);
   Point point3 = new Point(21, 13);
   Point point4 = new Point(34, 9);
   // 创建一个以点为元素的数组
   Point[] curvePoints = { point1, point2, point3, point4 };
   // 创建一个GraphicsPath 对象并添加一条曲线
   GraphicsPath gPath = new GraphicsPath();
   gPath.AddCurve(curvePoints, 0, 3, 0.8f);
   gPath.AddLine(36, 9, 378, 9);
   point1.X = 378; point1.Y = 9;
   point2.X = 387; point2.Y = 5;
   point3.X = 394; point3.Y = 0;
   Point[] curvePoints2 = { point1, point2, point3 };
   gPath.AddCurve(curvePoints2, 0, 2, 0.8f);
   gPath.AddLine(394, 0, 0, 0);
   Region rg = new Region(gPath);
   e.Graphics.ExcludeClip(rg);
  //可以为任意图片
   string str = Directory.GetCurrentDirectory() + "\\2.png";
   Image img = Image.FromFile(str);
   e.Graphics.DrawImage(img, 0, 0, 695, 278);
   // 重设剪切好的区域
   e.Graphics.ResetClip();
  }
 }
}