silverlight与ashx

subufan 2015-07-07 02:36:12

我用webclient上传文件，后台建立ashx用于保存文件，然后将文件名存入到数据库中并取得了新插入项主键id，我想返回这个id给silverlight客户端，请问该怎么做？换句话说，silverlight如何获取ashx的返回值？
UploadHander.ashx如下：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.IO;

using System.Data.SqlClient;

using WebGISApp.Web.General;



namespace WebGISApp.Web

{

  /// <summary>

  /// UploadHandler 的摘要说明

  /// </summary>

  public class UploadHandler : IHttpHandler

  {



    public void ProcessRequest(HttpContext context)

    {

      string filename = Uri.UnescapeDataString(Convert.ToString(context.Request.QueryString["InputFile"]));

      string fileExtend = System.IO.Path.GetExtension(filename);

      string fid = Uri.UnescapeDataString(Convert.ToString(context.Request.QueryString["Fid"]));

      string newGuidName = "";

      string errorString = "";

      SqlConnection sqlConnection = SqlHelper.OpenSqlConnection(ref errorString);

      SqlCommand myComm = new SqlCommand();

      myComm.Connection = sqlConnection;

      SqlTransaction st = sqlConnection.BeginTransaction();

      myComm.Transaction = st;

      try

      {

        newGuidName = Guid.NewGuid().ToString() + fileExtend;

        context.Response.ContentType = "text/plain";

        context.Response.ContentEncoding = System.Text.Encoding.Unicode;

        int ids = -1;

        try

        {       

          if (fid.Trim().ToUpper() != "NULL")

          {

            myComm.CommandText = string.Format(XMLHelper.GetCommandString("CataLogConfig/DeleteFileInfo", "value"), fid);

            File.Delete(context.Server.MapPath("~/" + Convert.ToString(myComm.ExecuteScalar())));

          }

          string strSQL = XMLHelper.GetCommandString("CataLogConfig/AddFileInfo", "value");

          myComm.CommandText = strSQL;

          myComm.Parameters.AddWithValue("@FileName", filename);

          myComm.Parameters.AddWithValue("@GuidName", "Files/" + newGuidName);



          //if (type.Trim() == "img")

          //{

          //  myComm.Parameters.AddWithValue("@Bid", bid);

          //}

          //else if (type.Trim() == "doc")

          //{

          //  myComm.Parameters.AddWithValue("@Did", did);

          //}

          ids = Convert.ToInt32(myComm.ExecuteScalar());

          st.Commit();   

        }

        catch

        {

          ids = -2;

          st.Rollback();

          return;

        }

        finally

        {

          context.Response.Write(ids.ToString());

        }



        using (FileStream fileStream = File.Create(context.Server.MapPath("~/Files/" + newGuidName)))

        {

          byte[] bufferData = new byte[4096];

          int bytesToBeRead;

          while ((bytesToBeRead = context.Request.InputStream.Read(bufferData, 0, bufferData.Length)) != 0)

          {

            fileStream.Write(bufferData, 0, bytesToBeRead);

          }

          fileStream.Close();

        }

      }

      catch

      {

        st.Rollback();

      }

      finally

      {

        myComm.Dispose();

        sqlConnection.Dispose();

      }

    }



    public bool IsReusable

    {

      get

      {

        return false;

      }



    }

  }

}