• 简单的ajax(菜鸟级)


    经常有朋友问我,Google,土豆网等那各种辅助输入功能是如何实现...我是用的ajax实现的.描述如下:

    一 创建输入页面 包含如下文本框

          <input id="txtSearch" style=" 348px"   onkeyup ="GetSearchString();"  type="text" />

         用户键盘输入时,触发onkeyup事件

    二 在js文件中创建ActiveXObject  并把txtSearch中已经输入的值日传递到CkNodifyNo.ashx页面 一座筛选,代码

     var xmlHttp;
       function CreateXmlHttpRequest()
       {
          if(window.ActiveXObject)
          {
            xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
           }
         else if(window.XMLHttpRequest)
         {
           xmlHttp=new XMLHttpRequest();
          }
        } 
      
       
     function GetSearchString()
       { 
        var StrSearch=document.getElementById("txtSearch").value;
       
           if(StrSearch.length>0)
           {
         
          CreateXmlHttpRequest();
          xmlHttp.open("GET","Hander/CkNodifyNo.ashx?SearchStr="+StrSearch,true);
          //"/"+document.getElementById('drpRoomNum').value,true)
          xmlHttp.onreadystatechange=callback;
          xmlHttp.send(null);   
          }
       }------------------------①此为js的一部分 另一部分在下面会贴出来的

     三  CkNodifyNo.ashx页面做出筛选,然后然会筛选结果 代码如下:

    <%@ WebHandler Language="C#" Class="CkNodifyNo" %>
    using System;
    using System.Web;
    using System.Data;
    using System.Data.SqlClient;

    public class CkNodifyNo : IHttpHandler {
       
        public void ProcessRequest (HttpContext context) {
            //context.Response.ContentType = "text/plain";
            //context.Response.Write("Hello World");

            //===============
            //睲埃絯
            context.Response.Expires = -1;
            if (!object.Equals(null, context.Request.QueryString["SearchStr"]))
            {
                string sth = context.Request.QueryString["SearchStr"].ToString();
                context.Response.ContentType = "text/plain";
                //context.Response.ContentType = "text/html";
                context.Response.Write(getString(sth));
                //context.Response.Write("OK");
                context.Response.End();
            }
            else
            {
                context.Response.ContentType = "text/html";
                context.Response.Write("NO");
                context.Response.End();
            }
        }


        private string getString(string sth)
        {
          
            string RetString = string.Empty;
            switch (sth) //为了方面这里没有操作数据库,写死了返回的字符串
            {
                case "t":
                    return "the^tea^teacher^tee^tett^tesbook^tesving^test^test programe";
                    break;
                case "te":
                    return "tea^teacher^tee^tett^tesbook^tesving^test^test programe";
                    break;
                case "tes":
                    return "tesbook^tesving^test^test programe";
                    break;
                case "test":
                    return "test programe";
                    break;
                default:
                    return "$#@$";
                    break;

            }
           
         
        }

     
        public bool IsReusable {
            get {
                return false;
            }
        }
       
    }

    四 在js页面接受然会值,并在页面上现实

      //HttpRequest回調函數
        function callback()
        {
       
          if(xmlHttp.readyState==4)
          {
           if(xmlHttp.status==200)
             {  
    //          try
    //           {
    //     
    //            var isOK= xmlHttp.responsetext.split('/');
    //            if(isOK[0]=='yes')
    //            {          
    //                document.getElementById("txtRoomID").value=isOK[1];
    //            }
                   if(xmlHttp.responsetext.length>0 )
                   {
                      if(xmlHttp.responsetext!='$#@$')
                      {
                      var StrLen= xmlHttp.responsetext.split('^');
                        // document.getElementById('divTest').innerText=xmlHttp.responsetext;
                        
                         var innerText;
                         innerText="<table border='0' cellpadding='0' cellspacing='0'>";
                         for(var i=0;i<StrLen.length;i++)
                         {
                             innerText+="<tr>";
                             innerText+="<td>";
                             innerText+="  <input id='"+i+"' type='text' onclick='getValue(this);' value='"+StrLen[i]+"' />";
                             innerText+="</td>";
                             innerText+="</tr>";
                         }
                         innerText+="</table>";
                         document.getElementById('divTest').innerHTML=innerText;
                  
                   }
                   else
                   {
                    document.getElementById('divTest').HtmlText="tte";
                    document.getElementById('divTest').style.display="";
                   }
            }
            
               
           }
        }
    }
    function getValue(obj)
    {
    document.getElementById("txtSearch").value=obj.value;
    document.getElementById('divTest').style.display="none";
    }------------------------------② 此为js的第另一部分 把 js ①② 放在一个js文件即可

    大功搞成  效果图:

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  • 原文地址:https://www.cnblogs.com/paulxie/p/1365694.html
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