asp.net接收post过来的json数据

public void ProcessRequest(HttpContext context)
{
    context.Response.ContentType = "application/json";
    context.Response.Cache.SetCacheability(HttpCacheability.NoCache);
    using (var reader = new System.IO.StreamReader(context.Request.InputStream))
    {
        string jsonData = reader.ReadToEnd();
        if (!string.IsNullOrEmpty(jsonData))
        {
            try
            {
                DALApiYian dal = new DALApiYian();
                dal.ReceiveOrder(jsonData);
            }
            catch { }
            context.Response.Write(jsonData);
        }
        else
        {
            context.Response.Write("FAIL");
        }
    }

}