Ajax简单示例

ajax 脚本请求：
<script language="javascript" type="text/javascript">
        function GetEmail(TID) {
            var Business = document.getElementById("Business");
            var subject = document.getElementById("subject");
            var ebody = document.getElementById("ebody");
            var comment = document.getElementById("comment");
            var situation = document.getElementById("situation");
            var panal1 = document.getElementById("panal1");
            var modify = document.getElementById("HlModify");
            var xhr = false;
            //创建对象
            xhr = CreatXmlHttp();
            //设置请求参数
            xhr.open("POST", "EmailTemplate.ashx?TID="+TID, true);
            //设置浏览器不缓存
            xhr.setRequestHeader("If-Modified-Since", "0");
            xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
            //设置回调
            xhr.onreadystatechange = function () {
                if (xhr.readyState == 4) {
                    if (xhr.status == 200) {
                        var Email = xhr.responseText;
                        var jsonobj = eval('(' + Email + ')');
                        panal1.style.visibility = "visible";
                        ebody.innerHTML = jsonobj.Body;
                        subject.innerHTML = jsonobj.Subject;
                        situation.innerHTML = jsonobj.Situation;
                        Business.innerHTML = jsonobj.Business_Type;
                        comment.innerHTML = jsonobj.Comment;
                        modify.href = "EmailTemplate_Modify.aspx?TID=" + jsonobj.TemplateID + "&BID=" + jsonobj.BID;
                       }
                }
            }
            //发送请求
            var param = "TID" + TID;
            xhr.send();
            //阻止服务端运行
            return false;
         }
         //创建xmlhttp对象
         function CreatXmlHttp() {
             var xhobj = false;
             try {
                 xhobj = new ActiveXObject("MSXML2.XMLHTTP");
                 }
             catch (e) 
             {
             try
             {
                 xhobj = new ActiveXObject("Microsoft.XMLHTTP");
             }
 
             catch (e1) {
                 xhobj = new XMLHttpRequest();
                        }
             }
         return xhobj;
         }
    </script>

一般处理程序，接受处理请求并返回处理结果：

 public void ProcessRequest (HttpContext context) {
        //设置请求格式
        context.Response.ContentType = "application/json";
        var TID = context.Request.Params["TID"].ToString();
        string sql = "select * from EmailGridV_View where TID= '"+TID+"'";
          DataTable dt = KB.DAL.SqlHelper.ExecuteDataset(KB.DAL.DB.SqlConnStr,CommandType.Text,sql).Tables[0];
          EmailInfo emi = new EmailInfo();
          if (dt.Rows.Count > 0)
          {
              emi.TemplateID = Int32.Parse(dt.Rows[0]["TID"].ToString());
              emi.Comment = dt.Rows[0]["Comment"].ToString();
              emi.Situation = dt.Rows[0]["Situation"].ToString();
              emi.Subject = dt.Rows[0]["subject"].ToString();
              emi.Body=dt.Rows[0]["Body"].ToString();
              emi.Business_Type = dt.Rows[0]["BusinessName"].ToString();
              emi.BID = Int32.Parse(dt.Rows[0]["BID"].ToString());
          }
          
        //序列化成json
          var json = new System.Runtime.Serialization.Json.DataContractJsonSerializer(emi.GetType());
          json.WriteObject(context.Response.OutputStream,emi);