图片圆角帮助类

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;

namespace BJSoft.WXYH.Server.JJFCC.Areas.JJFCC.Tool
{

    /// <summary>
    /// ImageOption 的摘要说明
    /// </summary>
    public class ImageOperation
    {
        /// <summary>
        /// 圆角生成（但是只能是一个角）
        /// </summary>
        /// <param name="image">源图片 Image</param>
        /// <param name="roundCorner">圆角位置</param>
        /// <returns>处理好的Image</returns>
        public static Image CreateRoundedCorner(Image image, RoundRectanglePosition roundCorner)
        {
            Graphics g = Graphics.FromImage(image);
            //保证图片质量
            g.SmoothingMode = SmoothingMode.HighQuality;
            g.InterpolationMode = InterpolationMode.HighQualityBicubic;
            g.CompositingQuality = CompositingQuality.HighQuality;
            Rectangle rect = new Rectangle(0, 0, image.Width, image.Height);
            //构建圆角外部路径
            GraphicsPath rectPath = CreateRoundRectanglePath(rect, image.Width / 10, roundCorner);
            //圆角背景用白色填充
            Brush b = new SolidBrush(Color.White);
            g.DrawPath(new Pen(b), rectPath);
            g.FillPath(b, rectPath);
            g.Dispose();
            return image;
        }
        /// <summary>
        /// 目标图片的圆角位置
        /// </summary>
        public enum RoundRectanglePosition
        {
            /// <summary>
            /// 左上角
            /// </summary>
            TopLeft,
            /// <summary>
            /// 右上角
            /// </summary>
            TopRight,
            /// <summary>
            /// 左下角
            /// </summary>
            BottomLeft,
            /// <summary>
            /// 右下角
            /// </summary>
            BottomRight
        }
        /// <summary>
        /// 构建GraphicsPath路径
        /// </summary>
        /// <param name="rect"></param>
        /// <param name="radius"></param>
        /// <param name="rrPosition">图片圆角位置</param>
        /// <returns>返回GraphicPath</returns>
        private static GraphicsPath CreateRoundRectanglePath(Rectangle rect, int radius, RoundRectanglePosition rrPosition)
        {
            GraphicsPath rectPath = new GraphicsPath();
            switch (rrPosition)
            {
                case RoundRectanglePosition.TopLeft:
                    {
                        rectPath.AddArc(rect.Left, rect.Top, radius * 2, radius * 2, 180, 90);
                        rectPath.AddLine(rect.Left, rect.Top, rect.Left, rect.Top + radius);
                        break;
                    }
                case RoundRectanglePosition.TopRight:
                    {
                        rectPath.AddArc(rect.Right - radius * 2, rect.Top, radius * 2, radius * 2, 270, 90);
                        rectPath.AddLine(rect.Right, rect.Top, rect.Right - radius, rect.Top);
                        break;
                    }
                case RoundRectanglePosition.BottomLeft:
                    {
                        rectPath.AddArc(rect.Left, rect.Bottom - radius * 2, radius * 2, radius * 2, 90, 90);
                        rectPath.AddLine(rect.Left, rect.Bottom - radius, rect.Left, rect.Bottom);
                        break;
                    }
                case RoundRectanglePosition.BottomRight:
                    {
                        rectPath.AddArc(rect.Right - radius * 2, rect.Bottom - radius * 2, radius * 2, radius * 2, 0, 90);
                        rectPath.AddLine(rect.Right - radius, rect.Bottom, rect.Right, rect.Bottom);
                        break;
                    }
            }
            return rectPath;
        }
        /// <summary>
        /// 图片缩放
        /// </summary>
        /// <param name="b">源图片Bitmap</param>
        /// <param name="dstWidth">目标宽度</param>
        /// <param name="dstHeight">目标高度</param>
        /// <returns>处理完成的图片 Bitmap</returns>
        public static Bitmap ResizeBitmap(Bitmap b, int dstWidth, int dstHeight)
        {
            Bitmap dstImage = new Bitmap(dstWidth, dstHeight);
            System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(dstImage);
            //   设置插值模式 
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Bilinear;
            //   设置平滑模式 
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            g.SmoothingMode = SmoothingMode.HighQuality;
            g.InterpolationMode = InterpolationMode.HighQualityBicubic;
            //用Graphic的DrawImage方法通过设置大小绘制新的图片实现缩放
            g.DrawImage(b, new Rectangle(0, 0, dstImage.Width, dstImage.Height), new Rectangle(0, 0, b.Width, b.Height), GraphicsUnit.Pixel);
            g.Save();
            g.Dispose();
            return dstImage;
        }
    }
}

  var headImage = Image.FromStream(new MemoryStream(headImageContent));//头像
                headImage = ImageOperation.CreateRoundedCorner(headImage, ImageOperation.RoundRectanglePosition.TopLeft);
                headImage = ImageOperation.CreateRoundedCorner(headImage, ImageOperation.RoundRectanglePosition.TopRight);
                headImage = ImageOperation.CreateRoundedCorner(headImage, ImageOperation.RoundRectanglePosition.BottomLeft);
                headImage = ImageOperation.CreateRoundedCorner(headImage, ImageOperation.RoundRectanglePosition.BottomRight);