图片流Base64编码 转图片

using System;

using  System.Drawing;
using  System.Drawing.Imaging;
using  System.IO;
using  System.Web;

namespace  OnlinePhotoCapture
{
    /// <summary>
    /// 将图片base64字符串原还原为图片并调整尺寸后保存(by 菩提树下的杨过http://yjmyzz.cnblogs.com/)
    /// </summary>
    public  class  SavePhoto : IHttpHandler
    {

        public  void  ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain" ;

            string  base64String = "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" ;

            Image bmp = null ;
            MemoryStream ms = null ;
            try
            {
                byte [] b = Convert.FromBase64String(base64String);
                ms = new  MemoryStream(b);
                bmp = ImageResize( new  Bitmap(ms),125,125);
                bmp.Save(context.Request.MapPath( "logo.jpg" ), ImageFormat.Jpeg);
                context.Response.Write( "success" );
            }
            catch  (Exception ex)
            {
                context.Response.Write( "failure:"  + ex.Message.ToString());
            }
            finally
            {
                bmp.Dispose();
                ms.Dispose();
            }

        }



        /// <summary>
        /// 修改图片尺寸
        /// </summary>
        /// <param name="imgSrc"></param>
        /// <returns></returns>
        private  Image ImageResize(Image imgSrc, int  width, int  height)
        {
            Image newImage = imgSrc.GetThumbnailImage(125, 125, null , new  IntPtr());
            Graphics g = Graphics.FromImage(newImage);
            g.DrawImage(newImage, 0, 0, newImage.Width, newImage.Height);
            g.Dispose();
            return  newImage;
        }


        public  bool  IsReusable
        {
            get
            {
                return  false ;
            }
        }

    }
}