//Byte[] result;

System.IO.MemoryStream ms =new MemoryStream(result, 0, result.Length)  
  Response.ClearContent();
  Response.ContentType = "image/Gif";
  Response.BinaryWrite(ms.ToArray());

或者添加一个处理图片的Handler，内容如下：
<%@ WebHandler Language="C#" Class="Handler" %>

using System.Web;
using System.IO;


public class Handler : IHttpHandler {
   
  public void ProcessRequest (HttpContext context) {
  
  int CategoryID = int.Parse(context.Request.QueryString["CategoryID"]);
  //调用Categories.GetPicture取得图片stream
  Stream stream = CategoriesPicture.GetPicture(CategoryID);
   
  if (stream !=null) {
  //取得图片stream大小
  int buffersize = (int)stream.Length;
  //建立buffer
  System.Byte[] buffer = new System.Byte[buffersize ] ;
  //调用stream.Read，从stream读取到buffer，并返回count
  int count = stream.Read(buffer, 0, buffersize);
  //返回图片字段buffer
  if (count!=0)
  context.Response.OutputStream.Write(buffer, 0, count);
  }

  }
 
  public bool IsReusable {
  get {
  return false;
  }
  }

}