使用通用处理程序检索二进制图像时出错

Question

public class Handler : IHttpHandler
{
    static DataTable dt;
    string url = ConfigurationManager.AppSettings["ServiceUrl"].ToString();

    public void ProcessRequest(HttpContext context)
    {
        string id = context.Request.QueryString["id"]; //get the querystring value that was pass on the ImageURL (see GridView MarkUp in Page1.aspx)

        if (id != null)
        {
            MemoryStream memoryStream = new MemoryStream();

            string json = ClsUtility.HttpGet(url + "Services/service.svc/ProductS/" + id);
            json = Regex.Unescape(json);
            dt = (DataTable)JsonConvert.DeserializeObject(json.Trim(new Char[] { ' ', '"', '.' }), typeof(DataTable));

            //Get Image Data
            byte[] file = (byte[])Convert.FromBase64String(dt.Rows[0]["ProductImage"].ToString());
            context.Response.ContentType = "image/jpg";
            context.Response.OutputStream.Write(file, 78, file.Length - 78); 

            memoryStream.Write(file, 0, file.Length);
            context.Response.Buffer = true;
            context.Response.BinaryWrite(file);
            context.Response.Flush();
        }
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }

}

这里我没有收到任何错误而没有显示图片

在.aspx中我尝试访问图像文件

<asp:Image ID="Image" runat="server" ImageUrl='<%# "Handler.ashx?id=" + Eval("ProductRowId")%>' />

不是产品名称告诉我在处理程序中做了什么错误