用代码的方式生成Form并提交表单

 /// <summary>
        /// 创建Form HTML代码
        /// </summary>
        /// <param name="parma">需要添加的参数</param>
        /// <param name="url">网关的Url</param>
        protected string GetForm(Dictionary<string, string> parma, string url)
        {
            string formItem = "<input type='hidden' name='{0}' value='{1}'>";
            StringBuilder html = new StringBuilder();

            html.AppendLine("<form name='Gateway' method='post'" + " action =" + url + ">");

            foreach (KeyValuePair<string, string> item in parma)
            {
                html.AppendLine(string.Format(formItem, item.Key, item.Value));
            }

            html.AppendLine("<input type='submit'id='submit' value='提交' style='display:none'/>");
            html.AppendLine("</form>");
            //html.AppendLine("<script type='text/javascript'>window.document.Gateway.submit();</script>");
            html.AppendLine("<script type='text/javascript'>window.document.getElementById('submit').click();</script>");
            return html.ToString();
        }