使用Generic Handler的动态图像（来自db）

我正在尝试使用Generic Handler来检索和显示存储在数据库中的图像。

但它只是不起作用。 我已经尝试了下面的代码，但我似乎无法让它工作。

anyonne可以发现我做错了什么，或者有一些建议吗？

 using System; using System.Web; using System.Linq; using System.Data.Entity; public class IconsDb : IHttpHandler { public void ProcessRequest (HttpContext context) { context.Response.ContentType = "text/plain"; context.Response.Write("Hello World"); Int32 iconId; if (context.Request.QueryString["id"] != null) iconId = Convert.ToInt32(context.Request.QueryString["id"]); else throw new ArgumentException("No parameter specified"); context.Response.ContentType = "image/gif"; //System.IO.Stream strm = ShowEmpImage(iconId); var db = new UdINaturen.UdINaturenContext(); var GetIcon = (from i in db.subcategoryicons where i.id == iconId select i.picture).FirstOrDefault(); object img = GetIcon; System.IO.MemoryStream memStream= new System.IO.MemoryStream((byte[])Convert.FromBase64String(GetIcon)); System.Drawing.Bitmap bitImage=new System.Drawing.Bitmap((System.Drawing.Bitmap)System.Drawing.Image.FromStream(memStream)); byte[] buffer = memStream.ToArray(); context.Response.ContentType = "image/gif"; //context.Response.OutputStream.Write(buffer, 0, buffer.Length); //context.Response.WriteFile(); context.Response.BinaryWrite(buffer); //context.Response.Flush(); } public bool IsReusable { get { return true; } } } 

Answer 1

哇，好的。 不知道有多少是旧代码，应该注释掉什么或者w / e但是尝试这样的事情：

 public void ProcessRequest (HttpContext context) { int iconId; if (string.IsNullOrEmpty(context.Request.QueryString["id"]) || !int.TryParse(context.Request.QueryString["id"], out iconId) ) throw new ArgumentException("No parameter specified"); context.Response.ContentType = "image/gif"; var db = new UdINaturen.UdINaturenContext(); var GetIcon = (from i in db.subcategoryicons where i.id == iconId select i.picture).FirstOrDefault(); byte[] buffer = (byte[])Convert.FromBase64String(GetIcon); context.Response.ContentType = "image/gif"; context.Response.BinaryWrite(buffer); context.Response.Flush(); }