这个是前台显示的页面代码↓
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_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 runat="server">
<title></title>
<script language="javascript" type="text/javascript">
function neihe() {//设置浏览器的内核
if (window.ActiveXObject) {//如果是IE浏览器内核
return new ActiveXObject("Microsoft.XMLHTTP");
} else if (window.XMLHttpRequest) {//否则
return new XMLHttpRequest();
}
}
var XMLduixiang;
function fasong(name) {
if (name != "") {
var url = encodeURI("houtai.aspx?chuandi=" + name); //encodeURI对URL编码
XMLduixiang = neihe(); //创建XMLGTttpRequest
XMLduixiang.onreadystatechange = huidiao; //回传处理结果(请求被发送到服务器时)
XMLduixiang.open("GET", url, true); //初始化XMLGTttpRequest组件
//最后的true（异步）或 false（同步）
XMLduixiang.send(null);//发送请求
}
}
function huidiao(){
if(XMLduixiang.readyState==4 && XMLduixiang.status == 200){
var cljg = XMLduixiang.responseText;
//responseText获得字符串形式的响应数据
//responseXML获得 XML 形式的响应数据
if(cljg=="true"){//如果返回真
document.getElementById("ts").style.display = "none";
} else {//否则
document.getElementById("ts").style.display = "inline";
}
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
输入用户名：
<input type="text" onblur="fasong(this.value)" /><%--失去焦点--%>
<span id="ts" style=" display:none; color:Red;">没有这个用户</span>
</div>
</form>
</body>
</html>
这个是后台页面的代码↓
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Configuration;
public partial class houtai : System.Web.UI.Page
{
string sjklj = ConfigurationManager.ConnectionStrings["ceshi"].ConnectionString;
protected void Page_Load(object sender, EventArgs e)
{
Response.ContentType = "text/plain";//设置输出类型
if (Request.QueryString["chuandi"] != null)
{
string name = Request.QueryString["chuandi"].ToString().Trim();
if (name.Length>0)
{
if (shifou(name))
{
Response.Write("true");
}
else
{
Response.Write("false");
}
}
else
{
Response.Write("false");
}
}
else
{
Response.Write("false");
}
}
protected bool shifou(string name)
{
string sql = "select * from cs where [email protected]";
using (SqlConnection conn = new SqlConnection(sjklj))
{
conn.Open();
SqlCommand cmd = new SqlCommand(sql, conn);
cmd.Parameters.AddRange(new SqlParameter[] { new SqlParameter("@name", name) });
if (cmd.ExecuteScalar() == null)
{
return false;
}
else
{
return true;
}
}
}
}
时间： 2024-08-24 10:16:17