Simple search implementation method based on ajax

This article mainly introduces the simple search implementation method based on ajax. It analyzes in detail the specific steps and related techniques of ajax call to implement the search function in the form of examples. It has certain reference value. Friends in need can refer to it

The example in this article describes a simple search implementation method based on ajax. Share it with everyone for your reference. The details are as follows:

Two .aspx files are used here, one is called Default.aspx and the other is called AjaxOperations.aspx. The first one is used to enter search data, and the latter one is used to Search keywords for processing. There is also a testJs.js file under the js folder, which is the core part of the ajax operation. Yes, code is cheap. Look at the code:

testJs.js

// 此函数等价于document.getElementById /document.all
function $(s) { if (document.getElementById) { return eval('document.getElementById("' + s + '")'); } else { return eval('document.all.' + s); } }
// 创建 XMLHttpRequest对象，以发送ajax请求 
function createXMLHTTP() {
 var xmlHttp = false;
 var arrSignatures = ["MSXML2.XMLHTTP.5.0", "MSXML2.XMLHTTP.4.0",
       "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP",
       "Microsoft.XMLHTTP"];
 for (var i = 0; i < arrSignatures.length; i++) {
  try {
   xmlHttp = new ActiveXObject(arrSignatures[i]);
   return xmlHttp;
  }
  catch (oError) {
   xmlHttp = false; //ignore
  }
 }
 // throw new Error("MSXML is not installed on your system."); 
 if (!xmlHttp && typeof XMLHttpRequest != &#39;undefined&#39;) {
  xmlHttp = new XMLHttpRequest();
 }
 return xmlHttp;
}
function addAjaxSearch() {
 inputField = $("txtSearch");
 completeTable = $("suggestTb");
 completep = $("popup");
 completeBody = $("suggestBody");
 var tempStr = inputField.value;
 // alert(tempStr);
 var keyWord = encodeURI(tempStr);
 if (tempStr == "")
  return;
 var xmlReq = createXMLHTTP();
 xmlReq.open("post", "AjaxOperations.aspx?searchKeyword=" + keyWord, true);
 xmlReq.onreadystatechange = function() {
  if (xmlReq.readyState == 4) {
   if (xmlReq.status == 200) {
    //xmlReq.responseText为输出的那段字符串
    setNames(xmlReq.responseText);
   }
   else {
    alert("Connect the server failed!");
   }
  }
 }
 xmlReq.send(null);
}
// 设置p中的表格数据
function setNames(names) {
 if (names == "") {
  clearNames();
  return;
 }
 clearNames(); // 清空p中已有的的表格数据
 setOffsets(); // 设置p到合适的位置
 var row, cell, txtNode;
 var s = names.split("#");
 for (var i = 0; i < s.length; i++) { // 显示类似search下拉选择项
  var nextNode = s[i];
  row = document.createElement("tr");
  cell = document.createElement("td");
  cell.onmouseout = function() { this.style.backgroundColor = &#39;&#39;; };
  cell.onmouseover = function() { this.style.backgroundColor = &#39;#E8F2FE&#39;; };
  cell.onclick = function() { completeField(this); }; // 搜索框设置为选择的数据
  cell.pop = "T";
  txtNode = document.createTextNode(nextNode);
  cell.appendChild(txtNode);
  row.appendChild(cell);
  $("suggestBody").appendChild(row);
 }
}
// 清空p中已有的的表格数据
function clearNames() {
 completeBody = $("suggestBody");
 var ind = completeBody.childNodes.length;
 for (var i = ind - 1; i >= 0; i--) {
  completeBody.removeChild(completeBody.childNodes[i]);
 }
 completep = $("popup");
 completep.style.border = "none";
}
// 设置p到合适的位置
function setOffsets() {
 completeTable.style.width = inputField.offsetWidth; +"px";
 var left = calculateOffset(inputField, "offsetLeft");
 var top = calculateOffset(inputField, "offsetTop") + inputField.offsetHeight;
 completep.style.border = "black 1px solid";
 completep.style.left = left + "px";
 completep.style.top = top + "px";
}
function calculateOffset(field, attr) {
 var offset = 0;
 while (field) {
  offset += field[attr];
  field = field.offsetParent;
 }
 return offset;
}
// 搜索框设置为选择的数据
function completeField(cell) {
 inputField.value = cell.firstChild.nodeValue; // 搜索框设置为选择的数据
 clearNames(); //清空p中已有的的表格数据
}
//用来设置当鼠标失去焦点后文本框的隐藏
document.onmousedown = function() {
 if (!event.srcElement.pop)
  clearNames();
} //填写输入框

Default.aspx：

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebTest2008.Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
 <title>Ajax Search</title>
 <script src="js/testJs.js" type="text/javascript"></script>
 <style type="text/css" media="screen">
  body
  {
   font: 11px arial;
  }
  .suggest_link
  {
   background-color: #FFFFFF;
   padding: 2px 0px 2px 0px;
   border:solid 1px #cceeff;
  }
  .suggest_link_over
  {
   background-color: #E8F2FE;
   padding: 2px 0px 2px 0px;
  }
  #search_suggest
  {
   position: absolute;
   background-color: #FFFFFF;
   text-align: left;
   border: 1px solid #000000;
  }
 </style>
</head>
<body>
 <input name="txtSearch" id="txtSearch" type="text" class="suggest_link" onkeyup="addAjaxSearch();" maxlength="200" style="width: 200px" /> 
 <input type="submit" id="cmdSearch" name="cmdSearch" value="Search" title="Run Search" />
 <p id="popup" style="position: absolute">
  <table id="suggestTb" cellspacing="0" cellpadding="0" bgcolor="#fffafa" border="0">
   <tbody id="suggestBody">
   </tbody>
  </table>
 </p>
</body>
</html>

Default.aspx.cs：

using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebTest2008
{
 public partial class Default : System.Web.UI.Page
 {
  protected void Page_Load(object sender, EventArgs e)
  {
  }
 }
}

AjaxOperations.aspx：

AjaxOperations.aspx.cs:

using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebTest2008
{
 public partial class AjaxOperations : System.Web.UI.Page
 {
  protected void Page_Load(object sender, EventArgs e)
  {
   if (!string.IsNullOrEmpty(Request["searchKeyword"]))
   {
    string tempStr = Request["searchKeyword"];
    /* 测试用 实际项目中可以对数据库进行检索等等相关操作，这里简化了 */
    System.Text.StringBuilder sb = new System.Text.StringBuilder();
    sb.Append(tempStr + " #");
    sb.Append("#");
    sb.Append(tempStr += " " + tempStr);
    sb.Append("#");
    sb.Append(tempStr += " " + tempStr);
    Response.Write(sb.ToString().TrimEnd(new char[] { '#' })); 
   }
  }
 }
}

The above is what I compiled for everyone. I hope it will be helpful to everyone in the future.

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