09.JavaScirpt window

2018-01-08  本文已影响0人  Lv_0
  1. 所有浏览器都支持window对象,它表示浏览器窗口本身;
  2. 所有 JavaScript 全局对象、全局函数以及全局变量均自动成为 window 对象的成员
  3. 全局变量是window对象的属性,全局函数是window对象的方法;
  4. document也是window对象的属性
<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            .code{
                color: gray;
                border: 1px solid gainsboro;
                font-size: 15px;
            }
            pre{
                margin: 1em 0em 1em -19em;
                font-family: "楷体";
            }
            .result{
                color: gray;
                background-color: ghostwhite;
                font-size: 16px;
                padding: 0.5em 1em;
            }
            h3{
                color: red;
            }
            .result span:first-child{
                display: block;
                float: left;
                width: 10em;
                color: black;
            }
        </style>
        <script type="text/javascript">
            function objDisplay(eleId,obj){
                if(typeof(eleId)!="string" || typeof(obj)!="object"){
                    alert("Function objDisplay() need the first parameter string and second object !")
                }else{
                    var ele = document.getElementById(eleId);
                
                    if(!ele || !obj){
                        alert("Please check the parameter !")
                    }else{
                        for(i in obj){
                            var div = document.createElement("div");
                            
                            for(var j=0;j<2;j++){
                                var span = document.createElement("span");
                                if(j==0) span.innerHTML = i+" : ";
                                else span.innerHTML = obj[i];
                                div.appendChild(span);
                            }
                        ele.appendChild(div);
                        }
                    }
                }               
            }
        </script>
    </head>
    <body>
        <ul>
            <li>
                <h3>window</h3>
                <h4>代码:</h4>
                <div class="code">
                    <pre>
                    //window属性和方法
                    var winDict = {
                        "windowWidth":window.innerWidth,
                        "windowHeight":window.innerHeight,
                        "window.open()":"打开新窗口",
                        "window.close()":"关闭当前窗口",
                        "window.moveTo()":"移动当前窗口",
                        "window.resizeTo()":"调整当前窗口的尺寸"
                    }
                    //涵盖所有浏览器的写法(浏览器的视口,不包括工具栏和滚动条)
                    var winHeight = window.innerHeight
                    ||document.documentElement.clientWidth
                    ||document.body.clientWidth;
                    
                    var winWidth = window.innerWidth
                    ||document.documentElement.clientWidth
                    ||document.body.clientWidth;
                    
                    objDisplay("winDict",winDict);
                    </pre>
                </div>              
                <h4>结果:</h4>
                <div id="winDict" class="result"></div>
                <hr />
                <script>
                    //window属性和方法
                    var winDict = {
                        "windowWidth":window.innerWidth,
                        "windowHeight":window.innerHeight,
                        "window.open()":"打开新窗口",
                        "window.close()":"关闭当前窗口",
                        "window.moveTo()":"移动当前窗口",
                        "window.resizeTo()":"调整当前窗口的尺寸"
                    }
                    //涵盖所有浏览器的写法(浏览器的视口,不包括工具栏和滚动条)
                    var winHeight = window.innerHeight
                    ||document.documentElement.clientWidth
                    ||document.body.clientWidth;
                    
                    var winWidth = window.innerWidth
                    ||document.documentElement.clientWidth
                    ||document.body.clientWidth;
                    
                    objDisplay("winDict",winDict);
                </script>
            </li>               
        </ul>       
    </body>
</html>
image.png

  1. window.screen 对象在实际写的时候,可以不写window;
  2. screen.availWidth/screen.availHeight 属性返回访问者屏幕的宽度/高度,以像素计,减去界面特性,比如窗口任务栏;
<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            .code{
                color: gray;
                border: 1px solid gainsboro;
                font-size: 15px;
            }
            pre{
                margin: 1em 0em 1em -19em;
                font-family: "楷体";
            }
            .result{
                color: gray;
                background-color: ghostwhite;
                font-size: 16px;
                padding: 0.5em 1em;
            }
            h3{
                color: red;
            }
            .result span:first-child{
                display: block;
                float: left;
                width: 10em;
                color: black;
            }
        </style>
        <script type="text/javascript">
            function objDisplay(eleId,obj){
                if(typeof(eleId)!="string" || typeof(obj)!="object"){
                    alert("Function objDisplay() need the first parameter string and second object !")
                }else{
                    var ele = document.getElementById(eleId);
                
                    if(!ele || !obj){
                        alert("Please check the parameter !")
                    }else{
                        for(i in obj){
                            var div = document.createElement("div");
                            
                            for(var j=0;j<2;j++){
                                var span = document.createElement("span");
                                if(j==0) span.innerHTML = i+" : ";
                                else span.innerHTML = obj[i];
                                div.appendChild(span);
                            }
                        ele.appendChild(div);
                        }
                    }
                }               
            }
        </script>
    </head>
    <body>
        <ul>
            <li>
                <h3>screen</h3>
                <h4>代码:</h4>
                <div class="code">
                    <pre>
                    //screen属性
                    var scrDict = {
                        "availWidth":window.screen.availWidth,
                        "windowHeight":screen.availHeight,
                    }
                    
                    objDisplay("winDict",scrDict);
                    </pre>
                </div>              
                <h4>结果:</h4>
                <div id="winDict" class="result"></div>
                <hr />
                <script>
                    //screen属性
                    var scrDict = {
                        "availWidth":window.screen.availWidth,
                        "windowHeight":screen.availHeight,
                    }
                    
                    objDisplay("winDict",scrDict);
                </script>
            </li>               
        </ul>       
    </body>
</html>
image.png

  1. window.location 对象用于获得当前页面的地址 (URL),并可以把浏览器重定向到新的页面;
  2. window.location 对象在编写时可不使用 window 这个前缀;
<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            .code{
                color: gray;
                border: 1px solid gainsboro;
                font-size: 15px;
            }
            pre{
                margin: 1em 0em 1em -19em;
                font-family: "楷体";
            }
            .result{
                color: gray;
                background-color: ghostwhite;
                font-size: 16px;
                padding: 0.5em 1em;
            }
            h3{
                color: red;
            }
            .result span:first-child{
                display: block;
                float: left;
                width: 10em;
                color: black;
            }
            button{
                background-color: blueviolet;
                color: white;
                border: 2px solid plum;
                border-radius: 2em;
                padding: 0.5em;
                margin: 0.5em;
            }
            button:focus{
                color: bisque;
            }
        </style>
        <script type="text/javascript">
            function objDisplay(eleId,obj){
                if(typeof(eleId)!="string" || typeof(obj)!="object"){
                    alert("Function objDisplay() need the first parameter string and second object !")
                }else{
                    var ele = document.getElementById(eleId);
                
                    if(!ele || !obj){
                        alert("Please check the parameter !")
                    }else{
                        for(i in obj){
                            var div = document.createElement("div");
                            
                            for(var j=0;j<2;j++){
                                var span = document.createElement("span");
                                if(j==0) span.innerHTML = i+" : ";
                                else span.innerHTML = obj[i];
                                div.appendChild(span);
                            }
                        ele.appendChild(div);
                        }
                    }
                }               
            }
        </script>
    </head>
    <body>
        <ul>
            <li>
                <h3>location</h3>
                <h4>代码:</h4>
                <div class="code">
                    <pre>
                    //location属性
                    var lcaDict = {
                        "hostname":window.location.hostname,//返回 web 主机的域名
                        "pathname":location.pathname,//返回当前页面的路径和文件名
                        "port":location.port,//返回 web 主机的端口
                        "protocol":location.protocol,//返回所使用的 web 协议(http:// 或 https://)
                        "href":location.href,//属性返回当前页面的 URL
                    }
                    
                    objDisplay("lcaDict",lcaDict);
                    </pre>
                </div>              
                <h4>结果:</h4>
                <div id="lcaDict" class="result"></div>
                <!--location.assign() 方法加载新的文档-->
                <button onclick="location.assign('https://www.jianshu.com/')">Assign</button>
                <hr />
                <script>
                    //location属性
                    var lcaDict = {
                        "hostname":window.location.hostname,//返回 web 主机的域名
                        "pathname":location.pathname,//返回当前页面的路径和文件名
                        "port":location.port,//返回 web 主机的端口
                        "protocol":location.protocol,//返回所使用的 web 协议(http:// 或 https://)
                        "href":location.href,//属性返回当前页面的 URL
                    }
                    
                    objDisplay("lcaDict",lcaDict);
                </script>
            </li>               
        </ul>       
    </body>
</html>
image.png

  1. history.back()方法加载历史列表中的前一个 URL,与在浏览器点击后退按钮相同;
  2. history.forward()方法加载历史列表中的下一个 URL,与在浏览器中点击按钮向前相同;
  3. window.history 对象在编写时可不使用 window 这个前缀
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <style>
            .code{
                color: gray;
                border: 1px solid gainsboro;
                font-size: 15px;
            }
            pre{
                margin: 1em 0em 1em -19em;
                font-family: "楷体";
            }
            .result{
                color: gray;
                background-color: ghostwhite;
                font-size: 16px;
            }
            ul li h3{
                color: red;
            }
            button{
                background-color: blueviolet;
                color: white;
                border: 2px solid plum;
                border-radius: 2em;
                padding: 0.5em;
                margin: 0.5em;
            }
            button:focus{
                color: bisque;
            }
        </style>
    </head>
    <body>
        <ul>
            <li>
                <h3>history</h3>
                <h4>代码:</h4>
                <div class="code">
                    <pre>
                    &lt;button name="back" onclick="window.history.back()"&gt;back&lt;/button&gt;
                    &lt;button name="forward" onclick="history.forward()"&gt;forward&lt;/button&gt;
                    </pre>
                </div>
                <h4>结果:</h4>
                <div class="result">
                    <button name="back" onclick="window.history.back()">back</button>
                    <button name="forward" onclick="history.forward()">forward</button>
                </div>
            </li>
            <hr />
        </ul>
    </body>
</html>
image.png

  1. window.navigator 对象包含有关访问者浏览器的信息;
  2. window.navigator 对象在编写时可不使用 window 这个前缀
  3. 来自 navigator 对象的信息具有误导性,不应该被用于检测浏览器版本
    navigator 数据可被浏览器使用者更改;
    浏览器无法报告晚于浏览器发布的新操作系统;
  4. 使用对象来检测浏览器,例:由于只有 Opera 支持属性 "window.opera",可以据此识别出 Opera
<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            .code{
                color: gray;
                border: 1px solid gainsboro;
                font-size: 15px;
            }
            pre{
                margin: 1em 0em 1em -19em;
                font-family: "楷体";
            }
            .result{
                color: gray;
                background-color: ghostwhite;
                font-size: 16px;
                padding: 0.5em 1em;
            }
            h3{
                color: red;
            }
            .result span:first-child{
                display: block;
                float: left;
                width: 10em;
                color: black;
            }
        </style>
        <script type="text/javascript">
            function objDisplay(eleId,obj){
                if(typeof(eleId)!="string" || typeof(obj)!="object"){
                    alert("Function objDisplay() need the first parameter string and second object !")
                }else{
                    var ele = document.getElementById(eleId);
                
                    if(!ele || !obj){
                        alert("Please check the parameter !")
                    }else{
                        for(i in obj){
                            var div = document.createElement("div");
                            
                            for(var j=0;j<2;j++){
                                var span = document.createElement("span");
                                if(j==0) span.innerHTML = i+" : ";
                                else span.innerHTML = obj[i];
                                div.appendChild(span);
                            }
                        ele.appendChild(div);
                        }
                    }
                }               
            }
        </script>
    </head>
    <body>
        <ul>
            <li>
                <h3>navigator</h3>
                <h4>代码:</h4>
                <div class="code">
                    <pre>
                    //navigator属性
                    var navDict = {
                        "appCodeName":window.navigator.appCodeName,
                        "appName":navigator.appName,
                        "appVersion":navigator.appVersion,
                        "cookieEnabled":navigator.cookieEnabled,
                        "platform":navigator.platform,
                        "userAgent":navigator.userAgent,
                        "systemLanguage":navigator.systemLanguage,
                    }
                    
                    objDisplay("navDict",navDict);
                    </pre>
                </div>              
                <h4>结果:</h4>
                <div id="navDict" class="result"></div>
                <hr />
                <script>
                    //navigator属性
                    var navDict = {
                        "appCodeName":window.navigator.appCodeName,
                        "appName":navigator.appName,
                        "appVersion":navigator.appVersion,
                        "cookieEnabled":navigator.cookieEnabled,
                        "platform":navigator.platform,
                        "userAgent":navigator.userAgent,
                        "systemLanguage":navigator.systemLanguage,
                    }
                    
                    objDisplay("navDict",navDict);
                </script>
            </li>               
        </ul>       
    </body>
</html>
image.png

  1. JavaScript中消息框有三种:警告框,确认框,提示框;
  2. 警告框alert(),警告框携带信息弹出,需点击"确认"按钮后,才能继续进行下一步操作;
  3. 确认框confirm(),确认框携带信息弹出,点击"确认"按钮后返回true,点击"取消"按钮后返回false
  4. 提示框prompt(),提示框携带信息弹出,且要求用户输入内容,若未输入或点击"取消"按钮,则返回null,若输入且点击"确定"按钮,则返回输入值
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <style>
            .code{
                color: gray;
                border: 1px solid gainsboro;
                font-size: 15px;
            }
            pre{
                margin: 1em 0em 1em -19em;
                font-family: "楷体";
            }
            .result{
                color: gray;
                background-color: ghostwhite;
                font-size: 16px;
            }
            ul li h3{
                color: red;
            }
            button{
                background-color: blueviolet;
                color: white;
                border: 2px solid plum;
                border-radius: 2em;
                padding: 0.5em;
                margin: 0.5em;
            }
            button:focus{
                color: bisque;
            }
        </style>
    </head>
    <body>
        <ul>
            <li>
                <h3>PopupAlert</h3>
                <h4>代码:</h4>
                <div class="code">
                    <pre>
                    &lt;button name="alert" onclick="alert('Hello World !')"&gt;Alert&lt;/button&gt;
                    &lt;button name="confirm" onclick="confirmResult()"&gt;Confirm&lt;/button&gt;
                    &lt;button name="prompt" onclick="promptResult()"&gt;Prompt&lt;/button&gt;
                    </pre>
                </div>
                <h4>结果:</h4>
                <div class="result">
                    <button name="alert" onclick="alert('Hello World !')">Alert</button>
                    <button name="confirm" onclick="confirmResult()">Confirm</button>
                    <button name="prompt" onclick="promptResult()">Prompt</button>
                </div>
                <div class="result">
                    <p id="confirmRes">显示Confirm按钮点击后的结果!</p>
                    <p id="promptRes">显示Prompt按钮点击后输入的结果!</p>
                </div>
            </li>
            <hr />
            <script>
                function confirmResult(){
                    var result = confirm("Continue ?");
                    document.getElementById("confirmRes").innerHTML = result;
                }
                function promptResult(){
                    var result = prompt("Please input the infomation !");
                    document.getElementById("promptRes").innerHTML = result;
                }
            </script>
        </ul>
    </body>
</html>
test27.gif

  1. setTimeout(),定时任务,在多长时间后,执行一次,只执行一次;
  2. clearTimeout(),清除定时任务.
  3. setInterval(),重复任务,每隔多长时间,就执行一次,重复执行;
  4. clearInterval(),清除重复任务.
<!DOCTYPE html>
<html>

    <head>
        <meta charset="UTF-8">
        <title></title>
        <style>
            .code {
                color: gray;
                border: 1px solid gainsboro;
                font-size: 15px;
            }
            
            pre {
                margin: 1em 0em 1em -19em;
                font-family: "楷体";
            }
            
            .result {
                color: gray;
                background-color: ghostwhite;
                font-size: 16px;
            }
            
            ul li h3 {
                color: red;
            }
            
            button {
                background-color: blueviolet;
                color: white;
                border: 2px solid plum;
                border-radius: 2em;
                padding: 0.5em;
                margin: 0.5em;
            }
            
            button:focus {
                color: bisque;
            }
        </style>
    </head>

    <body>
        <ul>
            <li>
                <h3>timing</h3>
                <h4>代码:</h4>
                <div class="code">
                    <pre>
                    //定义全局变量
                    var initDate = "";
                    var nowDateAll = "";

                    //时钟
                    function dateDisRef() {
                        var now = new Date(); //定义当前时间
                        var dateAll = "";
                        //定义时间字典
                        var dateDict = {
                            "year": now.getFullYear(),
                            "month": now.getMonth() + 1,
                            "day": now.getDate(),
                            "hours": now.getHours(),
                            "minutes": now.getMinutes(),
                            "seconds": now.getSeconds()
                        }
                        //格式校验,不足十的,在前方补0
                        function checkDate(dateTime, dateDict) {
                            if(dateDict[dateTime] < 10) {
                                dateDict[dateTime] = "0" + dateDict[dateTime];
                            }
                        }
                        //日期展示
                        for(dateTime in dateDict) {
                            checkDate(dateTime, dateDict);
                            switch(dateTime) {
                                case "year":
                                case "month":
                                    dateAll += (dateDict[dateTime] + "-");
                                    break;
                                case "hours":
                                case "minutes":
                                    dateAll += (dateDict[dateTime] + ":");
                                    break;
                                case "day":
                                    dateAll += (dateDict[dateTime] + " ");
                                    break;
                                case "seconds":
                                    dateAll += dateDict[dateTime];
                                default:
                                    break;
                            }
                        }
                        document.getElementById("dateDis").innerHTML = dateAll;
                        nowDateAll = dateAll;
                        //只设置一次
                        if(initDate == "") {
                            //替换第一个空格为T,用来设置日历默认时间
                            initDate = dateAll.replace(" ", "T");
                        }
                        //定时任务,等待500ms,执行dateDisRef()方法,调用后再次等待500ms,再会进行下次调用,故刷新频率为1s
                        var timeOut = setTimeout('dateDisRef()', 500);
                    }
                    //调用方法
                    dateDisRef();

                    //设置日历默认时间为当前时间
                    document.getElementById("initDate").value = initDate;

                    //倒计时
                    var interval;

                    function timing() {
                        //获得日历时间,并进行格式转换
                        var calendarTime = document.getElementById("initDate").value.toString();
                        //进行同时区时间设置(防止时差问题,导致时间差错误),均设置为标准时区
                        var calendarDate = new Date(calendarTime + "Z");
                        //动态获取当前时间
                        var nowDate = new Date(nowDateAll + "Z");
                        //将时间差转化为s
                        var dateMius = (calendarDate - nowDate) / 1000;
                        //清除重复任务,防止生成多个
                        clearInterval(interval);
                        //定义重复任务,时间间隔1s
                        interval = setInterval(function() {
                            dateMius--;
                            var timingEle = document.getElementById("timing");
                            if(dateMius == 0) {
                                timingEle.innerHTML = "倒计时结束!";
                                timingEle.style.color = "red";
                                clearInterval(interval);
                            } else {
                                if(timingEle.style.color == "red") timingEle.style.color = "gray";
                                timingEle.innerHTML = dateMius + " S";
                            }
                        }, 1000);
                    }
                    </pre>
                </div>
                <h4>结果:</h4>
                <div class="result">
                    <p id="dateDis"></p>
                </div>
                <div class="result">
                    <input type="datetime-local" id="initDate" onchange="timing()" />
                    <p id="timing"></p>
                </div>
                <script>
                    //定义全局变量
                    var initDate = "";
                    var nowDateAll = "";

                    //时钟
                    function dateDisRef() {
                        var now = new Date(); //定义当前时间
                        var dateAll = "";
                        //定义时间字典
                        var dateDict = {
                            "year": now.getFullYear(),
                            "month": now.getMonth() + 1,
                            "day": now.getDate(),
                            "hours": now.getHours(),
                            "minutes": now.getMinutes(),
                            "seconds": now.getSeconds()
                        }
                        //格式校验,不足十的,在前方补0
                        function checkDate(dateTime, dateDict) {
                            if(dateDict[dateTime] < 10) {
                                dateDict[dateTime] = "0" + dateDict[dateTime];
                            }
                        }
                        //日期展示
                        for(dateTime in dateDict) {
                            checkDate(dateTime, dateDict);
                            switch(dateTime) {
                                case "year":
                                case "month":
                                    dateAll += (dateDict[dateTime] + "-");
                                    break;
                                case "hours":
                                case "minutes":
                                    dateAll += (dateDict[dateTime] + ":");
                                    break;
                                case "day":
                                    dateAll += (dateDict[dateTime] + " ");
                                    break;
                                case "seconds":
                                    dateAll += dateDict[dateTime];
                                default:
                                    break;
                            }
                        }
                        document.getElementById("dateDis").innerHTML = dateAll;
                        nowDateAll = dateAll;
                        //只设置一次
                        if(initDate == "") {
                            //替换第一个空格为T,用来设置日历默认时间
                            initDate = dateAll.replace(" ", "T");
                        }
                        //定时任务,等待500ms,执行dateDisRef()方法,调用后再次等待500ms,再会进行下次调用,故刷新频率为1s
                        var timeOut = setTimeout('dateDisRef()', 500);
                    }
                    //调用方法
                    dateDisRef();

                    //设置日历默认时间为当前时间
                    document.getElementById("initDate").value = initDate;

                    //倒计时
                    var interval;

                    function timing() {
                        //获得日历时间,并进行格式转换
                        var calendarTime = document.getElementById("initDate").value.toString();
                        //进行同时区时间设置(防止时差问题,导致时间差错误),均设置为标准时区
                        var calendarDate = new Date(calendarTime + "Z");
                        //动态获取当前时间
                        var nowDate = new Date(nowDateAll + "Z");
                        //将时间差转化为s
                        var dateMius = (calendarDate - nowDate) / 1000;
                        //清除重复任务,防止生成多个
                        clearInterval(interval);
                        //定义重复任务,时间间隔1s
                        interval = setInterval(function() {
                            dateMius--;
                            var timingEle = document.getElementById("timing");
                            if(dateMius == 0) {
                                timingEle.innerHTML = "倒计时结束!";
                                timingEle.style.color = "red";
                                clearInterval(interval);
                            } else {
                                if(timingEle.style.color == "red") timingEle.style.color = "gray";
                                timingEle.innerHTML = dateMius + " S";
                            }
                        }, 1000);
                    }
                </script>
            </li>
            <hr />
        </ul>
    </body>

</html>
image.png
test28.gif

  1. cookie 是存储于访问者的计算机中的变量。每当同一台计算机通过浏览器请求某个页面时,就会发送这个 cookie
  2. 名字 cookie
    当访问者首次访问页面时,他或她也许会填写他/她们的名字。名字会存储于 cookie 中。当访问者再次访问网站时,他们会收到类似 "Welcome John Doe!" 的欢迎词。而名字则是从 cookie 中取回的。
    密码 cookie
    当访问者首次访问页面时,他或她也许会填写他/她们的密码。密码也可被存储于 cookie 中。当他们再次访问网站时,密码就会从 cookie 中取回。
    日期 cookie
    当访问者首次访问你的网站时,当前的日期可存储于 cookie 中。当他们再次访问网站时,他们会收到类似这样的一条消息:"Your last visit was on Tuesday August 11, 2005!"。日期也是从 cookie 中取回的。
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body onload="checkCookie()">
        <script>
            //设置cookie
            function setCookies(name,value,expiredays){
                var exdate = new Date();
                //设置失效日期
                exdate.setDate(exdate.getDate()+expiredays);
                //设置cookie格式 name=value;expires=exdate
                //escape()用来编码字符串 toGMTString()此日期会在转换为字符串之前由本地时区转换为 GMT时区
                document.cookie=name+"="+escape(value)+((expiredays==null)?"":(";expires="+exdate.toGMTString()));
            }
            
            //获取cookie
            function getCookies(name){
                //判断cookie的长度
                if(document.cookie.length>0){
                    //获取要获取cookie的起始位置
                    start = document.cookie.indexOf(name+"=");
                    //判断indexOf()搜索结果,无结果时为-1
                    if(start!=-1){
                        start = start+name.length+1;//设置起始值为=的位置
                        end = document.cookie.indexOf(";",start);//从起始值搜索到名字的结束
                        if(end==-1) end=document.cookie.length;//无失效日期,则取到尾
                        return unescape(document.cookie.substring(start,end));//解码截取的子字符串
                    }
                }
                return "";
            }
            
            //检查是否设置了cookie
            function checkCookie(){
                usrName = getCookies("usrName");//获取usrCookie
                //不为空弹出欢迎框
                if(usrName!=null && usrName!=""){
                    alert("Welcome again "+usrName+" !");
                }else{
                    //为空则弹出消息框,提示用户输入名字,并设置cookie
                    usrName=prompt("Please enter your name :","");
                    if(usrName!=null&&usrName!=""){
                        setCookies("usrName",usrName,30);
                    }
                }
            }
        </script>
    </body>
</html>              
test29.gif

上一篇下一篇

猜你喜欢

热点阅读