/// <summary>发送异步请求</summary>
        /// <param name="requestData">请求的数据</param>
        /// <param name="httpMethod">请求的方式( GET | POST )</param>
        /// <param name="contentType">内容类型</param>
        /// <param name="content">内容</param>
        /// <param name="callback">回调函数</param>
        public static void RequestAsync(AjaxRequestData requestData, string httpMethod, string contentType, string content, InvokeAsyncCallbackDelegate callback)
        {
            AjaxRequest request = new AjaxRequest(requestData, callback);

            request.RequestAsync(requestData.ActionUri, httpMethod, contentType, content);
        }
        /// <summary>发送异步请求</summary>
        /// <param name="requestData">请求的数据</param>
        /// <param name="callback">回调函数</param>
        public static void RequestAsync(AjaxRequestData requestData, InvokeAsyncCallbackDelegate callback)
        {
            AjaxRequest request = new AjaxRequest(requestData, callback);

            request.RequestAsync(requestData.ActionUri, "POST");
        }