通过 Region 设置 Winform 圆角，圆角大小不相同的问题

[LifeChina555]

图中红色的是个Panel，我在这个Panel的Paint中

private void panel1_Paint(object sender, PaintEventArgs e)
    {
      GraphicsPath path = CreatePath(
          new Rectangle(0, 0, panel1.Width, panel1.Height), 20);
      panel1.Region = new System.Drawing.Region(path);
    }

CreatePath方法如下

public static GraphicsPath CreatePath(Rectangle rect, int radius)
    {
      int w = rect.Width;
      int h = rect.Height;

      GraphicsPath path = new GraphicsPath();

      int val = style.GetHashCode();
      path.AddArc(1, 1, radius, radius, 180, 90);
      path.AddArc(w - radius - 1, 1, radius, radius, 270, 90);
      path.AddArc(w - radius - 1, h - radius - 1, radius, radius, 0, 90);
      path.AddArc(1, h - radius - 1, radius, radius, 90, 90);

问题是绘出的图左上角的圆角大小和右下角圆角，明显不一样
左下角和右上角也是不一样的，不过没那么明显
请高人教导

[LifeChina555]

刚刚 GraphicsPath 方法没发全

public static GraphicsPath CreatePath(Rectangle rect, int radius)
    {
      int w = rect.Width;
      int h = rect.Height;

      GraphicsPath path = new GraphicsPath();

      int val = style.GetHashCode();
      path.AddArc(1, 1, radius, radius, 180, 90);
      path.AddArc(w - radius - 1, 1, radius, radius, 270, 90);
      path.AddArc(w - radius - 1, h - radius - 1, radius, radius, 0, 90);
      path.AddArc(1, h - radius - 1, radius, radius, 90, 90);
      return path;
}

[Jia_H]

把AddArc里面的1换成0看看,如下。
offset改为1的时候就是你原来的结果：

            int offset = 0;
            path.AddArc(offset, offset, radius, radius, 180, 90);
            path.AddArc(w - radius - offset, offset, radius, radius, 270, 90);
            path.AddArc(w - radius - offset, h - radius - offset, radius, radius, 0, 90);
            path.AddArc(offset, h - radius - offset, radius, radius, 90, 90);
            return path;

[yang2948443]

这个不会啊，帮楼主顶一下，也学习一下。