文本框异步自动检测数据库
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="TxT自定义检测数据库_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>无标题页</title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="scriptmanger1" runat="server">
<Scripts>
<asp:ScriptReference Path="~/TxT自定义检测数据库/jscript.js" />
</Scripts>
</asp:ScriptManager>
<div>
<input id="TextName" type="text" onblur="checkname()" />
<div style="background-color:Blue; font-weight:bold ; color:Red ; display:none" id="loadingflag">正在加载数据........</div><br />
<span id="NameError" style="color:#ff0033;"></span>
</div>
</form>
</body>
</html>
新建一个一般处理文件de：
<%@ WebHandler Language="C#" Class="De" %>
using System;
using System.Web;
using System.Data;
using System.Data.SqlClient;
public class De : IHttpHandler {
public void ProcessRequest (HttpContext context) {
context.Response.ContentType = "text/plain";
// context.Response.Write("Hello World");
if (context.Request.QueryString["type"].ToString().Trim() == "1")
{
var name = context.Request.QueryString["name"].ToString().Trim();
var back = Class1.get(name);
switch (back)
{
case 1:
context.Response.Write(1);
break;
case 2:
context.Response.Write(2);
break;
case 3:
context.Response.Write(3);
break;
}
}
else
{
context.Response.Write(3);
}
}
public bool IsReusable {
get {
return false;
}
}
}
js里的代码：
/// <reference name="MicrosoftAjax.js"/>
var xmlhttp=false;
try
{
xmlhttp=new ActiveXObject("Msxml2.MLHTTP");
}
catch(E)
{
try
{
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
catch(E)
{
xmlhttp=new XMLHttpRequest();//兼容非IE浏览器，直接创建XMLHTTP对象
}
}
function checkname()
{
document.getElementById("NameError").innerHTML="";
var username=document.getElementById("TextName").value;
var reg="[^a-zA-Z_0-9]";
var regl="\\D";
if(username=="") //判断不能为空
{
document.getElementById("NameError").innerHTML="<font color=\"red\">用户名不能空!</font></br>";
return;
}
else{// 向服务器发送。。
chened();
}
}
function chened()
{
var name=document.getElementById("TextName").value;
var strurl="De.ashx?type=1&name="+name;
xmlhttp.open("GET",strurl,true);
xmlhttp.onreadystatechange=function ()
{
if(xmlhttp.readystate==4 && xmlhttp.status==200)
{
var date=xmlhttp.responseText;
if(date!="")
{
switch(date)
{
case "1":
document.getElementById("NameError").innerHTML="<font color=\"red\">此用户存在</font></br>";
document.getElementById("loadingflag").style.display='none';
break;
case "2":
document.getElementById("NameError").innerHTML="<font color=\"red\">此用户不存在!</font></br>";
document.getElementById("loadingflag").style.display='none';
break;
case "3":
document.getElementById("NameError").innerHTML="<font color=\"red\">系统错误!</font></br>";
document.getElementById("loadingflag").style.display='none';
break;
}
}
}
}
xmlhttp.send(null);
document.getElementById("loadingflag").style.display='none';
}
连接数库据基础类：
public static string con = "data source=.;database=OfficeData;uid=sa;pwd=1234";
// public string sql = "";
public static SqlConnection mycon = new SqlConnection();
public static SqlCommand mycom = new SqlCommand();
public static int get(string name)
{
try
{
if (name.Length < 0 || name != "")
{
string sql = String.Format("SELECT * FROM UserTable WHERE (UserName = '{0}')", name);
// string sql = "";
mycon.ConnectionString =con;
mycon.Open();
mycom.Connection = mycon;
mycom.CommandText = sql;
int i=Convert.ToInt32(mycom.ExecuteScalar());
if (i>0)
return 1;//表示有数据
else
{
return 2;//表示没有数据
}
}
else
return 3;
}
catch (Exception)
{
return 3;
}
finally
{
mycon.Close();
}
}