用AJAX实现google输入自动完成的简单模拟(转)

本文链接：https://blog.youkuaiyun.com/chenguangcheng/article/details/5467576

本文介绍了一个简单的AJAX实现方案，用于模拟Google输入自动完成功能。该方案通过在用户输入公司名称时，从SqlServer2000的NorthWind数据库中搜索匹配的公司名称，并通过AJAX异步加载的方式实时展示搜索结果。

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用AJAX实现google输入自动完成的简单模拟

2009-03-02 13:00

比较简单的模拟,文本框输入CompanyName,然后
搜索SqlServer2000 里NorthWind数据库 Suppliers表的CompanyName字段,
然后实现自动完成

四个文件
1 .AutoComplete.htm

<!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>
     <title>输入自动完成</title>
     <script language="javascript">
        //输入信息的文本框
        var txtInput;
        //下拉表当前选中项的索引
        var currentIndex = -1;

        //初始化参数,和下拉表位置
        function initPar()
         {
              txtInput = document.getElementById("txtCompanyName");
             //设置下拉表相对于文本输入框的位置
              setPosition();
         }

        //设置下拉表相对于文本输入框的位置
        function setPosition()
         {
            var width = txtInput.offsetWidth;
            var left = getLength("offsetLeft");
            var top = getLength("offsetTop") + txtInput.offsetHeight;

             divContent.style.left = left + "px";
             divContent.style.top = top + "px";
             divContent.style.width = width + "px";
         }

       //获取对应属性的长度
        function getLength(attr)
         {
            var offset = 0;
            var item = txtInput;
            while (item)
             {
                 offset += item[attr];
                 item = item.offsetParent;
             }
            return offset;
         }

        //自动完成
        function autoComplete()
         {
            //如果按下向上, 向下或回车
            if (event.keyCode == 38 || event.keyCode == 40 || event.keyCode == 13)
             {
                //选择当前项
                 selItemByKey();
             }
            else //向服务器发送请求
             {
                //如果值为空
                if (txtInput.value == "")
                 {
                     divContent.style.display='none';
                    return;
                 }
                //恢复下拉选择项为 -1
                 currentIndex = -1;

                //开始请求
                 requestObj = new ActiveXObject("Microsoft.XMLHTTP");
                 requestObj.onreadystatechange = displayResult;
                 requestObj.open("POST", "AutoComplete.aspx?ts=" + new Date().toLocaleString(), true);
                 requestObj.send(txtInput.value);
             }
         }

        //显示结果
        function displayResult()
         {
             if (requestObj.readyState == 4)
              {
                      showData();
                      divContent.style.display = "";
              }
         }

        //显示服务器返回的结果 ,并形成下拉表
        function showData()
         {
             //获取数据
             var doc = new ActiveXObject("MSXML2.DOMDocument.3.0");
              doc.loadXML(requestObj.responseText);

             //显示数据的xslt
             var docStyle = new ActiveXObject("MSXML2.FreeThreadedDOMDocument");
              docStyle.async = false;
              docStyle.load("list.xslt");

             var docTemplate = new ActiveXObject("MSXML2.XSLTemplate");
              docTemplate.stylesheet = docStyle;

             //通过xslt转换xml数据
             var processor = docTemplate.createProcessor();
              processor.input = doc;
              processor.transform();
             var res = processor.output;

             //显示转后后的结果
              divContent.innerHTML = res;
         }

        //通过键盘选择下拉项
        function selItemByKey()
         {
            //下拉表
            var tbl = document.getElementById("tblContent");
            if (!tbl)
             {
                return;
             }
            //下拉表的项数
            var maxRow = tbl.rows.length;
            //向上
            if (event.keyCode == 38 && currentIndex > 0)
             {
                  currentIndex--;
             }
            //向下
            else if (event.keyCode == 40 && currentIndex < maxRow-1)
             {
                  currentIndex++;
             }
            //回车
            else if (event.keyCode == 13)
             {
                 selValue();
                return;
             }

             clearColor();
             txtInput.value = tbl.rows[currentIndex].innerText;
            //设置当前项背景颜色为blue 标记选中
             tbl.rows[currentIndex].style.backgroundColor = "InfoBackground";
         }

        //清除下拉项的背景颜色
        function clearColor()
         {
             var tbl = document.getElementById("tblContent");
             for (var i = 0; i < tbl.rows.length; i++)
              {
                     tbl.rows[i].style.backgroundColor = "";
              }
         }

        //选择下拉表中当前项的值 ,用于按回车或鼠标单击选中当前项的值
        function selValue()
         {
            if (event.keyCode != 13)
             {
                var text = event.srcElement.innerText;
                 txtInput.value = text;
             }
             initList();
         }

        //文本框失去焦点时设置下拉表可见性
        function setDisplay()
         {
            //获取当前活动td的表格
            if (document.activeElement.tagName == "TD")
             {
                 var tbl = document.activeElement.parentElement.parentElement.parentElement;
                //如果不是下拉表,则隐藏下拉表
                if (tbl.id != "tblContent")
                 {
                     initList();
                 }
                return;
             }

             initList();

         }

        function initList()
         {
             divContent.style.display='none';
             divContent.innerHTML = "";
             currentIndex = -1;
         }
     </script>
</head>
<body onload="initPar()">
CompanyName<input type="text" id="txtCompanyName" onkeyup="autoComplete()" onblur="setDisplay();" style="width:400px"/>

<div id="divContent" style="display:none; position:absolute; ">
</div>
</body>
</html>

AutoComplete.aspx

<%@ Page Language="C#" CodeBehind="AutoComplete.aspx.cs" Inherits="AJAXBaseHome.AutoComplete" %>

AutoComplete.aspx.cs

using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Collections;
using System.IO;
using System.Text;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.Configuration;

namespace AJAXBaseHome
{
    public partial class AutoComplete : System.Web.UI.Page
     {
        private static string conString = WebConfigurationManager.ConnectionStrings["myData"].ConnectionString;

        protected void Page_Load(object sender, EventArgs e)
         {
            string input = GetInput();
             Response.Write(GetCompanyName(input));
         }

        //获取输入的字符串
        private string GetInput()
         {
             Stream s = Request.InputStream;
            int count = 0;
            byte[] buffer = new byte[1024];
             StringBuilder builder = new StringBuilder();
            while ((count = s.Read(buffer, 0, 1024)) > 0)
             {
                 builder.Append(Encoding.UTF8.GetString(buffer, 0, count));
             }

            return builder.ToString();
         }

        private string GetCompanyName(string input)
         {
            using (SqlConnection con = new SqlConnection(conString))
             {
                 SqlCommand command = new SqlCommand("select * from suppliers where CompanyName like @Name", con);
                 command.Parameters.Add(new SqlParameter("@name", input + "%"));
                 SqlDataAdapter adapter = new SqlDataAdapter(command);
                 DataSet ds = new DataSet();
                 adapter.Fill(ds);
                return ds.GetXml();
             }
         }
     }
}

xslt文件用于显示xml数据

<?xml version="1.0" encoding="UTF-8" ?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="html"/>
  <xsl:template match="/">
    <xsl:apply-templates/>
  </xsl:template>
  <xsl:template match="NewDataSet">
    <table id="tblContent" style="background-color:GrayText">
    <xsl:for-each select="Table">
      <tr>
        
        <td onclick="selValue()" style="cursor:hand" onmouseover="clearColor();this.parentElement.style.backgroundColor='InfoBackground'" onmouseout="clearColor()">
          <xsl:value-of select="CompanyName"/>
        </td>
      </tr>
    </xsl:for-each>
    </table>
  </xsl:template>
</xsl:stylesheet>