asp.netashx接收post数据

 if (context.Request.InputStream != null)
        {
            byte[] postData = new byte[context.Request.InputStream.Length];
            context.Request.InputStream.Read(postData, 0, postData.Length);
            string postDataString = System.Text.Encoding.UTF8.GetString(postData);
            context.Response.Write(postDataString);            
     }