JQuery遮罩层登录界面实现（AJAX实现登录验证，源码下载）

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操作系统：Windwos7 Ultimate

开发工具：Visual Studio 2010

数据库：Sql Server 2005

测试浏览器：IE8、FF3.6.8、Google Chrome （IE8中弹出登录层后会出现竖拉条，其他两种没有出现，那个竖拉条可以在JS中通过修改数值让其不出现，但是下面会出现白边，越来越觉得IE有点那个了......）

1、预览

1）登录前

2）点击登录显示登录窗口（层），同时用一个灰色透明层遮罩主窗体内容，点击【登录】，隐藏【登录】，显示loading图，登录失败，显示【登录】，隐藏登录图，同时显示提示信息

3）登录成功后，去掉去掉遮罩层和登录层，显示“xxx，您好！ ”

2、实现

使用VS2010创建一个Web Site，此功能是在母版页Site.master中实现的。VS2010会自动添加JQuery的js文件到Scripts文件夹，并创建一个母版页和基于此母版页的Default.aspx和About.aspx两个窗体。

1）登录层界面设计，看Site.master中的代码

class="language-html">Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--><%@ Master Language="C#" AutoEventWireup="true" CodeFile="Site.master.cs" Inherits="SiteMaster" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head runat="server">
    <title>FlyNoteBook</title>
    <script src="Scripts/class="tags" href="/tags/JQUERY.html" title=jquery>jquery-1.4.1.min.js" type="text/javascript"></script>
    <script type="text/javascript" src="Scripts/common.js"></script>
    <link href="~/Styles/Site.css" rel="stylesheet" type="text/css" />
    <script type="text/javascript" src="Scripts/login.js"></script>
    <asp:ContentPlaceHolder ID="HeadContent" runat="server">
    </asp:ContentPlaceHolder>
</head>
<body>
    <form runat="server">
    <div class="page">
        <div class="header">
            <div class="title">
                  <img src="Images/Pictures/logo3.png" alt="FlyNoteBook Logo" />
                 FlyNoteBook
            </div>
            <div class="loginDisplay">
                <span id="popup" runat="server">登录</span>
                <span id="loginSuccess" runat="server"></span>
            </div>
            <div class="clear hideSkiplink">
                <asp:Menu ID="NavigationMenu" runat="server" CssClass="menu" EnableViewState="false"
                    IncludeStyleBlock="false" Orientation="Horizontal">
                    <Items>
                        <asp:MenuItem NavigateUrl="~/Default.aspx" Text="首页" />
                        <asp:MenuItem NavigateUrl="~/About.aspx" Text="关于" />
                    </Items>
                </asp:Menu>
            </div>
        </div>
        <!--登录窗口:Begin-->
        <div id="divLoginWindow">
            <table style="width: 100%;" border="0" cellpadding="2" cellspacing="0">
                <tr style="background-color: #e0f3d9; border-bottom: #bfe5b3 solid 2px">
                    <td style="height: 38px; width: 100px;">
                         用户登录
                    </td>
                    <td>
                        <img src="Images/Button/close.gif" id="closeBtn" align="absmiddle" alt="关闭" title="关闭" />
                    </td>
                </tr>
                <tr>
                    <td colspan="2" style="height: 5px;">
                    </td>
                </tr>
                <tr>
                    <td align="right">
                         用户名：
                    </td>
                    <td>
                         <asp:TextBox ID="txtUserName" runat="server"></asp:TextBox>
                    </td>
                </tr>
                <tr>
                    <td align="right">
                         密   码：
                    </td>
                    <td>
                         <asp:TextBox ID="txtPassword" TextMode="Password" runat="server"></asp:TextBox>
                    </td>
                </tr>
                <tr>
                    <td align="right">
                         验证码：
                    </td>
                    <td>
                         <asp:TextBox ID="txtCode" Style="width: 88px;" runat="server"></asp:TextBox>
                        <img src="Code.aspx" id="imgRndCode" style="vertical-align: middle;" οnclick="ChangeCode(this);"
                            alt="验证码" title="看不清，点击图片更换图片" />
                    </td>
                </tr>
                <tr>
                    <td colspan="2" align="center">
                        <a οnclick="CheckLogin()" id="alogin">登 录</a>
                        <img id="loading" src="Images/Loading/loading04.gif" alt="正在登录" title="正在登录..." />
                        <br />
                        <span id="showMes"></span>
                    </td>
                </tr>
            </table>
        </div>
        <!--登录窗口:End-->
        <div class="main">
            <asp:ContentPlaceHolder ID="MainContent" runat="server" />
        </div>
        <div class="clear">
        </div>
    </div>
    <div class="footer">
        <a href="http://www.cnblogs.com/Ferry/">By Ferry</a>
    </div>
    </form>
</body>
</html>

2）实现遮罩层和弹出登录界面的层的js文件Scripts/common.js的代码，注意，里面硬写了一些母版页Site.master中的元素的ID

class="language-html">Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->$(class="tags" href="/tags/FUNCTION.html" title=function>function () {
    var screenwidth, screenheight, mytop, getPosLeft, getPosTop
    screenwidth = $(window).width();
    screenheight = $(window).height();
    //获取滚动条距顶部的偏移
    mytop = $(document).scrollTop();
    //计算弹出层的left
    getPosLeft = screenwidth / 2 - 200;
    //计算弹出层的top
    getPosTop = screenheight / 2 - 150;
    //css定位弹出层
    $("#divLoginWindow").css({ "left": getPosLeft, "top": getPosTop });
    //当浏览器窗口大小改变时
    $(window).resize(class="tags" href="/tags/FUNCTION.html" title=function>function () {
        screenwidth = $(window).width();
        screenheight = $(window).height();
        mytop = $(document).scrollTop();
        getPosLeft = screenwidth / 2 - 200;
        getPosTop = screenheight / 2 - 150;
        $("#divLoginWindow").css({ "left": getPosLeft, "top": getPosTop + mytop });
    });
    //当拉动滚动条时，弹出层跟着移动
    $(window).scroll(class="tags" href="/tags/FUNCTION.html" title=function>function () {
        screenwidth = $(window).width();
        screenheight = $(window).height();
        mytop = $(document).scrollTop();
        getPosLeft = screenwidth / 2 - 200;
        getPosTop = screenheight / 2 - 150;
        $("#divLoginWindow").css({ "left": getPosLeft, "top": getPosTop + mytop });
    });
    //点击链接弹出登录窗口
    $("#popup").click(class="tags" href="/tags/FUNCTION.html" title=function>function () {
        $("#divLoginWindow").fadeIn("slow"); //toggle("slow"); 
        $("#txtUserName").focus();
        //获取页面文档的高度
        var docheight = $(document).height();
        //追加一个层，使背景变灰
        $("body").append("<div id='greybackground'></div>");
        $("#greybackground").css({ "opacity": "0.5", "height": docheight });
        return false;
    });
    //点击关闭按钮
    $("#closeBtn").click(class="tags" href="/tags/FUNCTION.html" title=function>function () {
        $("#divLoginWindow").fadeOut("slow"); hide();
        //删除变灰的层
        $("#greybackground").remove();
        return false;
    });
});

//更换验证码图片
class="tags" href="/tags/FUNCTION.html" title=function>function ChangeCode(obj) {
    obj.src = "Code.aspx?" + Math.random();
}

3）点击【登录】实现AJAX登录验证功能的js文件Scripts/login.js的代码

class="language-javascript">Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->var count = 0;
$(document).ready(class="tags" href="/tags/FUNCTION.html" title=function>function () {
    $("#loading").hide()
});

class="tags" href="/tags/FUNCTION.html" title=function>function CheckLogin() {
    $("#alogin").hide();
    $("#loading").show();
    var txtCode = $("#txtCode");
    var txtName = $("#txtUserName");
    var txtPwd = $("#txtPassword");
    $.class="tags" href="/tags/AJAX.html" title=ajax>ajax({
        url: "CheckLogin.aspx?Code=" + txtCode.val() + "&Name=" + txtName.val() + "&Pwd=" + txtPwd.val(),
        type: "post",
        datatype: "text",
        success: class="tags" href="/tags/FUNCTION.html" title=function>function (returnValue) {
            if (returnValue != "false") {
                $("#popup").hide();
                $("#showMes").hide();
                $("#loginSuccess").html(returnValue + '，您好!');
                $("#divLoginWindow").remove();
                $("#greybackground").remove();
                $("#showMes").hide();
            }
            else {
                count = count + 1;
                $("#loading").hide();
                $("#alogin").show();
                $("#showMes").show();
                $("#showMes").html("<font color=red>登录失败，请检查后重试!(" + count + "次)</font>");
            }
        }
    })
}

4）请求的CheckLogin.aspx的后台代码，前台清除剩Page命令一行

class="language-javascript">Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->using System;
using System.Data;

public partial class CheckLogin : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        try
        {
            String strCode = Request.QueryString["Code"];
            String strName = Request.QueryString["Name"];
            String strPassword = Request.QueryString["Pwd"];

            if (strCode != Session["Code"].ToString())
            {
                Response.Write("false");
            }
            else
            {
                DAO.SqlHelper helper = new DAO.SqlHelper();
                DataTable dt = helper.FillDataTable(String.Format("Select UserName,TrueName From Clients Where UserName='{0}' And Password='{1}'",
                    strName,
                    strPassword
                    ));
                if (dt != null && dt.Rows.Count > 0)
                {
                    Session["TrueName"] = dt.Rows[0]["TrueName"].ToString();
                    Response.Write(dt.Rows[0]["TrueName"].ToString());
                }
                else
                {
                    Response.Write("false");
                }
            }
        }
        catch
        {
            Response.Write("false");
        }
    }
}