ajax 服务器文本框自动填值

这样的话就增加了服务器的负担。后面自己他细想了一下。想利用ajax去实现这样一个效果。代码如下：
前台代码：
复制代码 代码如下:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ServerTextBoxdata.aspx.cs" Inherits="Default3" %>












后台代码：
复制代码 代码如下:
using System;
using System.Data;
using System.Configuration;
using System.Collections;
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.Data.SqlClient;
public partial class Default3 : System.Web.UI.Page
{
string StrAction = "";
protected void Page_Load(object sender, EventArgs e)
{
StrAction = Request["action"];
//为服务器控件添加失去焦点的事件 让服务器控件不刷新的关键
Txtusename.Attributes.Add("onblur", "WritedataText()");
Txtusename.Focus();
if (StrAction == "action")
{
//获取用户输入的名称
string username = Request["Username"];
if (!Isusername(username))
{
Response.Clear();
Response.ContentType = "application/text";
Response.Write("no");
Response.End();
}
else
{
InitData(username);
}
}
}
///

/// 创建人：周昕
/// 创建时间：2009-06-11
/// 方法名称：InitData
/// 作用：查找用户的详细信息
///

///
public void InitData(string username)
{
SqlConnection mycon = new SqlConnection();
mycon.ConnectionString = ConfigurationManager.ConnectionStrings["BoBoConn"].ToString();
string sql = "select Fullname,Email,MobilePhone,QQ from loginuser where username='"+username+"'";
mycon.Open();
SqlCommand mycom = new SqlCommand(sql, mycon);
SqlDataReader myda = mycom.ExecuteReader();
while (myda.Read())
{
string fullname = myda["Fullname"].ToString();
string Email = myda["Email"].ToString();
string MobilePhone = myda["MobilePhone"].ToString();
string QQ = myda["QQ"].ToString();
string array = fullname + "," + Email + "," + MobilePhone+","+QQ;
Response.Clear();
Response.ContentType = "application/text";
Response.Write(array);
Response.End();
}
}
///

/// 创建人：周昕
/// 创建时间：2009-06-11
/// 方法名称：Isusername
/// 作用：返回bool值判断用户是否存在
///

///
///
public bool Isusername(string username)
{
SqlConnection mycon = new SqlConnection();
mycon.ConnectionString = ConfigurationManager.ConnectionStrings["BoBoConn"].ToString();
string sql = "select count(*) from loginuser where username='" + username + "'";
mycon.Open();
SqlCommand mycom = new SqlCommand(sql, mycon);
int n = (int)mycom.ExecuteScalar();
mycon.Close();
if (n > 0)
{
return true;
}
else
{
return false;
}
}
}

效果：运行前只有用户名文本框可用

当用户输入用户名称后：鼠标离开文本框后效果如下：