Vue简介教程(六)[混入 | 响应接口

Vue简介教程(六)[混入 | 响应接口 | 实例]

Vue.js 响应接口

Vue 可以添加数据动态响应接口。

例如以下实例，我们通过使用 (watch 属性来实现数据的监听，)watch 必须添加在 Vue 实例之外才能实现正确的响应。

实例中通过点击按钮计数器会加 1。setTimeout 设置 10 秒后计算器的值加上 20 。

<div id = "app">
    <p style = "font-size:25px;">计数器: {{ counter }}</p>
    <button @click = "counter++" style = "font-size:25px;">点我</button>
</div>
<script type = "text/javascript">
var vm = new Vue({
    el: '#app',
    data: {
        counter: 1
    }
});
vm.$watch('counter', function(nval, oval) {
    alert('计数器值的变化 :' + oval + ' 变为 ' + nval + '!');
});
setTimeout(
    function(){
        vm.counter += 20;
    },10000
);
</script>

Vue 不允许在已经创建的实例上动态添加新的根级响应式属性。

Vue 不能检测到对象属性的添加或删除，最好的方式就是在初始化实例前声明根级响应式属性，哪怕只是一个空值。

如果我们需要在运行过程中实现属性的添加或删除，则可以使用全局 Vue，Vue.set 和 Vue.delete 方法。

Vue.set
Vue.set 方法用于设置对象的属性，它可以解决 Vue 无法检测添加属性的限制，语法格式如下：

Vue.set( target, key, value )

参数说明：

target: 可以是对象或数组
key : 可以是字符串或数字
value: 可以是任何类型

<div id = "app">
   <p style = "font-size:25px;">计数器: {{ products.id }}</p>
   <button @click = "products.id++" style = "font-size:25px;">点我</button>
</div>
<script type = "text/javascript">
var myproduct = {"id":1, name:"book", "price":"20.00"};
var vm = new Vue({
   el: '#app',
   data: {
      products: myproduct
   }
});
vm.products.qty = "1";
console.log(vm);
vm.$watch('products.id', function(nval, oval) {
   alert('计数器值的变化 :' + oval + ' 变为 ' + nval + '!');
});
</script>

在以上实例中，使用以下代码在开始时创建了一个变量 myproduct：

var myproduct = {"id":1, name:"book", "price":"20.00"};
该变量在赋值给了 Vue 实例的 data 对象：

var vm = new Vue({ el: '#app', data: { products: myproduct } });
如果我们想给 myproduct 数组添加一个或多个属性，我们可以在 Vue 实例创建后使用以下代码：

vm.products.qty = "1";

查看控制台输出：

如上图看到的，在产品中添加了数量属性 qty，但是 get/set 方法只可用于 id，name 和 price 属性，却不能在 qty 属性中使用。

我们不能通过添加 Vue 对象来实现响应。 Vue 主要在开始时创建所有属性。如果我们要实现这个功能，可以通过 Vue.set 来实现：

<div id = "app">
<p style = "font-size:25px;">计数器: {{ products.id }}</p>
<button @click = "products.id++" style = "font-size:25px;">点我</button>
</div>
<script type = "text/javascript">
var myproduct = {"id":1, name:"book", "price":"20.00"};
var vm = new Vue({
   el: '#app',
   data: {
      products: myproduct
   }
});
Vue.set(myproduct, 'qty', 1);
console.log(vm);
vm.$watch('products.id', function(nval, oval) {
   alert('计数器值的变化 :' + oval + ' 变为 ' + nval + '!');
});
</script>

从控制台输出的结果可以看出 get/set 方法可用于qty 属性。

Vue.delete

Vue.delete 用于删除动态添加的属性语法格式：

Vue.delete( target, key )

参数说明：

target: 可以是对象或数组
key : 可以是字符串或数字

<div id = "app">
   <p style = "font-size:25px;">计数器: {{ products.id }}</p>
   <button @click = "products.id++" style = "font-size:25px;">点我</button>
</div>
<script type = "text/javascript">
var myproduct = {"id":1, name:"book", "price":"20.00"};
var vm = new Vue({
   el: '#app',
   data: {
      products: myproduct
   }
});
Vue.delete(myproduct, 'price');
console.log(vm);
vm.$watch('products.id', function(nval, oval) {
   alert('计数器值的变化 :' + oval + ' 变为 ' + nval + '!');
});
</script>

以上实例中我们使用 Vue.delete 来删除 price 属性。以下是控制台输出结果：

从上图输出结果中，我们可以看到 price 属性已删除，只剩下了 id 和 name 属性，price 属性的 get/set 方法也已删除。

Vue.js 实例]

本章节为大家介绍几个 Vue.js 实例，通过实例练习来巩固学到的知识点。

导航菜单实例

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Vue.js 导航菜单</title>
    <script src="https://cdn.staticfile.org/vue/2.4.2/vue.min.js"></script>
    <style>

	*{
		margin:0;
		padding:0;
	}

	body{
		font:15px/1.3 'Open Sans', sans-serif;
		color: #5e5b64;
		text-align:center;
	}

	a, a:visited {
		outline:none;
		color:#389dc1;
	}

	a:hover{
		text-decoration:none;
	}

	section, footer, header, aside, nav{
		display: block;
	}

	/*-------------------------
		菜鸟
	--------------------------*/

	nav{
		display:inline-block;
		margin:60px auto 45px;
		background-color:#5597b4;
		box-shadow:0 1px 1px #ccc;
		border-radius:2px;
	}

	nav a{
		display:inline-block;
		padding: 18px 30px;
		color:#fff !important;
		font-weight:bold;
		font-size:16px;
		text-decoration:none !important;
		line-height:1;
		text-transform: uppercase;
		background-color:transparent;

		-webkit-transition:background-color 0.25s;
		-moz-transition:background-color 0.25s;
		transition:background-color 0.25s;
	}

	nav a:first-child{
		border-radius:2px 0 0 2px;
	}

	nav a:last-child{
		border-radius:0 2px 2px 0;
	}

	nav.home .home,
	nav.projects .projects,
	nav.services .services,
	nav.contact .contact{
		background-color:#e35885;
	}

	p{
		font-size:22px;
		font-weight:bold;
		color:#7d9098;
	}

	p b{
		color:#ffffff;
		display:inline-block;
		padding:5px 10px;
		background-color:#c4d7e0;
		border-radius:2px;
		text-transform:uppercase;
		font-size:18px;
	}

    </style>

</head>
<body>

<div id="main">

	<!-- 激活的菜单样式为  active 类 -->
	<!-- 为了阻止链接在点击时跳转，我们使用了 "prevent" 修饰符 (preventDefault 的简称)。 -->

	<nav v-bind:class="active" v-on:click.prevent>

		<!-- 当菜单上的链接被点击时，我们调用了 makeActive 方法, 该方法在 Vue 实例中创建。 -->

		<a href="#" class="home" v-on:click="makeActive('home')">Home</a>
		<a href="#" class="projects" v-on:click="makeActive('projects')">Projects</a>
		<a href="#" class="services" v-on:click="makeActive('services')">Services</a>
		<a href="#" class="contact" v-on:click="makeActive('contact')">Contact</a>
	</nav>

 	<!-- 以下 "active" 变量会根据当前选中的值来自动变换 -->

	<p>您选择了 <b>{{active}} 菜单</b></p>
</div>

<script>
// 创建一个新的 Vue 实例
var demo = new Vue({
	// DOM 元素，挂载视图模型
	el: '#main',

	// 定义属性，并设置初始值
	data: {
		active: 'home'
	},

	// 点击菜单使用的函数
	methods: {
		makeActive: function(item){
			// 模型改变，视图会自动更新
			this.active = item;
		}
	}
});
</script>
</body>
</html>

编辑文本实例

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Vue.js 文本编辑</title>
    <script src="https://cdn.staticfile.org/vue/2.4.2/vue.min.js"></script>
    <style>
    /* 隐藏未编译的变量 */

    [v-cloak] {
      display: none;
    }

    *{
        margin:0;
        padding:0;
    }

    body{
        font:15px/1.3 'Open Sans', sans-serif;
        color: #5e5b64;
        text-align:center;
    }

    a, a:visited {
        outline:none;
        color:#389dc1;
    }

    a:hover{
        text-decoration:none;
    }

    section, footer, header, aside, nav{
        display: block;
    }


    /*-------------------------
        编辑框
    --------------------------*/

    .tooltip{
        background-color:#5c9bb7;

        background-image:-webkit-linear-gradient(top, #5c9bb7, #5392ad);
        background-image:-moz-linear-gradient(top, #5c9bb7, #5392ad);
        background-image:linear-gradient(top, #5c9bb7, #5392ad);

        box-shadow: 0 1px 1px #ccc;
        border-radius:3px;
         290px;
        padding: 10px;

        position: absolute;
        left:50%;
        margin-left:-150px;
        top: 80px;
    }

    .tooltip:after{
        /* 提示信息 */
        content:'';
        position:absolute;
        border:6px solid #5190ac;
        border-color:#5190ac transparent transparent;
        0;
        height:0;
        bottom:-12px;
        left:50%;
        margin-left:-6px;
    }

    .tooltip input{
        border: none;
         100%;
        line-height: 34px;
        border-radius: 3px;
        box-shadow: 0 2px 6px #bbb inset;
        text-align: center;
        font-size: 16px;
        font-family: inherit;
        color: #8d9395;
        font-weight: bold;
        outline: none;
    }

    p{
        font-size:22px;
        font-weight:bold;
        color:#6d8088;
        height: 30px;
        cursor:default;
    }

    p b{
        color:#ffffff;
        display:inline-block;
        padding:5px 10px;
        background-color:#c4d7e0;
        border-radius:2px;
        text-transform:uppercase;
        font-size:18px;
    }

    p:before{
        content:'✎';
        display:inline-block;
        margin-right:5px;
        font-weight:normal;
        vertical-align: text-bottom;
    }

    #main{
        height:300px;
        position:relative;
        padding-top: 150px;
    }
    </style>

</head>
<body>

<!-- v-cloak 隐藏未编译的变量，直到 Vue 实例准备就绪。 -->
<!-- 元素点击后 hideTooltp() 方法被调用 -->

<div id="main" v-cloak v-on:click="hideTooltip">

    <!-- 这是一个提示框
         v-on:clock.stop 是一个点击事件处理器，stop 修饰符用于阻止事件传递
         v-if 用来判断 show_tooltip 为 true 时才显示 -->

    <div class="tooltip" v-on:click.stop v-if="show_tooltip">

        <!-- v-model 绑定了文本域的内容
         在文本域内容改变时，对应的变量也会实时改变  -->

        <input type="text" v-model="text_content" />
    </div>

    <!-- 点击后调用 "toggleTooltip" 方法并阻止事件传递 -->

    <!--  "text_content" 变量根据文本域内容的变化而变化 -->

    <p v-on:click.stop="toggleTooltip">{{text_content}}</p>

</div>

<script>
var demo = new Vue({
    el: '#main',
    data: {
        show_tooltip: false,
        text_content: '点我，并编辑内容。'
    },
    methods: {
        hideTooltip: function(){
            // 在模型改变时，视图也会自动更新
            this.show_tooltip = false;
        },
        toggleTooltip: function(){
            this.show_tooltip = !this.show_tooltip;
        }
    }
})
</script>
</body>
</html>

订单列表实例

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Vue.js 订单表单</title>
    <script src="https://cdn.staticfile.org/vue/2.4.2/vue.min.js"></script>
    <style>
    /*  隐藏未编译的变量 */

    [v-cloak] {
      display: none;
    }

    *{
    	margin:0;
    	padding:0;
    }

    body{
    	font:15px/1.3 'Open Sans', sans-serif;
    	color: #5e5b64;
    	text-align:center;
    }

    a, a:visited {
    	outline:none;
    	color:#389dc1;
    }

    a:hover{
    	text-decoration:none;
    }

    section, footer, header, aside, nav{
    	display: block;
    }

    /*-------------------------
    	订单表单
    --------------------------*/

    form{
    	background-color: #61a1bc;
    	border-radius: 2px;
    	box-shadow: 0 1px 1px #ccc;
    	 400px;
    	padding: 35px 60px;
    	margin: 50px auto;
    }

    form h1{
    	color:#fff;
    	font-size:64px;
    	font-family:'Cookie', cursive;
    	font-weight: normal;
    	line-height:1;
    	text-shadow:0 3px 0 rgba(0,0,0,0.1);
    }

    form ul{
    	list-style:none;
    	color:#fff;
    	font-size:20px;
    	font-weight:bold;
    	text-align: left;
    	margin:20px 0 15px;
    }

    form ul li{
    	padding:20px 30px;
    	background-color:#e35885;
    	margin-bottom:8px;
    	box-shadow:0 1px 1px rgba(0,0,0,0.1);
    	cursor:pointer;
    }

    form ul li span{
    	float:right;
    }

    form ul li.active{
    	background-color:#8ec16d;
    }

    div.total{
    	border-top:1px solid rgba(255,255,255,0.5);
    	padding:15px 30px;
    	font-size:20px;
    	font-weight:bold;
    	text-align: left;
    	color:#fff;
    }

    div.total span{
    	float:right;
    }
    </style>

</head>
<body>

<!-- v-cloak 隐藏未编译的变量，直到 Vue 实例准备就绪。 -->

<form id="main" v-cloak>

	<h1>Services</h1>

	<ul>

		<!-- 循环输出 services 数组, 设置选项点击后的样式 -->

		<li v-for="service in services" v-on:click="toggleActive(service)" v-bind:class="{ 'active': service.active}">

			<!-- 显示订单中的服务名，价格
                 Vue.js 定义了货币过滤器，用于格式化价格 -->

			{{service.name}} <span>{{service.price | currency}}</span>

		</li>
	</ul>

	<div class="total">

		<!-- 计算所有服务的价格，并格式化货币 -->

		Total: <span>{{total() | currency}}</span>
        
	</div>

</form>
<script>

// 自定义过滤器 "currency". 
Vue.filter('currency', function (value) {
    return '$' + value.toFixed(2);
});

var demo = new Vue({
    el: '#main',
    data: {
    	// 定义模型属性 the model properties. The view will loop
        // 视图将循环输出数组的数据
        services: [
        	{
        		name: 'Web Development',
        		price: 300,
        		active:true
        	},{
        		name: 'Design',
        		price: 400,
        		active:false
        	},{
        		name: 'Integration',
        		price: 250,
        		active:false
        	},{
        		name: 'Training',
        		price: 220,
        		active:false
        	}
        ]
    },
    methods: {
    	toggleActive: function(s){
            s.active = !s.active;
    	},
    	total: function(){

        	var total = 0;

        	this.services.forEach(function(s){
        		if (s.active){
        			total+= s.price;
        		}
        	});

    	   return total;
        }
    }
});
	
</script>
</body>
</html>

搜索页面实例

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Vue.js 搜索页面</title>
    <script src="https://cdn.staticfile.org/vue/2.4.2/vue.min.js"></script>
    
    <style>
    /* 隐藏未编译的变量 */

    [v-cloak] {
      display: none;
    }

    *{
        margin:0;
        padding:0;
    }

    body{
        font:15px/1.3 'Open Sans', sans-serif;
        color: #5e5b64;
        text-align:center;
    }

    a, a:visited {
        outline:none;
        color:#389dc1;
    }

    a:hover{
        text-decoration:none;
    }

    section, footer, header, aside, nav{
        display: block;
    }


    /*-------------------------
        搜索输入框
    --------------------------*/

    .bar{
        background-color:#5c9bb7;

        background-image:-webkit-linear-gradient(top, #5c9bb7, #5392ad);
        background-image:-moz-linear-gradient(top, #5c9bb7, #5392ad);
        background-image:linear-gradient(top, #5c9bb7, #5392ad);

        box-shadow: 0 1px 1px #ccc;
        border-radius: 2px;
         400px;
        padding: 14px;
        margin: 45px auto 20px;
        position:relative;
    }

    .bar input{
        background:#fff no-repeat 13px 13px;
        background-image:url(data:image/png;base64,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);

        border: none;
         100%;
        line-height: 19px;
        padding: 11px 0;

        border-radius: 2px;
        box-shadow: 0 2px 8px #c4c4c4 inset;
        text-align: left;
        font-size: 14px;
        font-family: inherit;
        color: #738289;
        font-weight: bold;
        outline: none;
        text-indent: 40px;
    }

    ul{
        list-style: none;
         428px;
        margin: 0 auto;
        text-align: left;
    }

    ul li{
        border-bottom: 1px solid #ddd;
        padding: 10px;
        overflow: hidden;
    }

    ul li img{
        60px;
        height:60px;
        float:left;
        border:none;
    }

    ul li p{
        margin-left: 75px;
        font-weight: bold;
        padding-top: 12px;
        color:#6e7a7f;
    }
    </style>

</head>
<body>

<form id="main" v-cloak>

    <div class="bar">
        <!-- searchString 模型与文本域创建绑定 -->

        <input type="text" v-model="searchString" placeholder="输入搜索内容" />
    </div>

    <ul>
        <!-- 循环输出数据 -->
             
        <li v-for="article in filteredArticles">
            <a v-bind:href="article.url"><img v-bind:src="article.image" /></a>
            <p>{{article.title}}</p>
        </li>
    </ul>

</form>
<script>

var demo = new Vue({
    el: '#main',
    data: {
        searchString: "",

        // 数据模型，实际环境你可以根据 Ajax 来获取

        articles: [
            {
                "title": "What You Need To Know About CSS Variables",
                "url": "https://www.runoob.com/css/css-tutorial.html",
                "image": "https://static.runoob.com/images/icon/css.png"
            },
            {
                "title": "Freebie: 4 Great Looking Pricing Tables",
                "url": "https://www.runoob.com/html/html-tutorial.html",
                "image": "https://static.runoob.com/images/icon/html.png"
            },
            {
                "title": "20 Interesting JavaScript and CSS Libraries for February 2016",
                "url": "https://www.runoob.com/css3/css3-tutorial.html",
                "image": "https://static.runoob.com/images/icon/css3.png"
            },
            {
                "title": "Quick Tip: The Easiest Way To Make Responsive Headers",
                "url": "https://www.runoob.com/css3/css3-tutorial.html",
                "image": "https://static.runoob.com/images/icon/css3.png"
            },
            {
                "title": "Learn SQL In 20 Minutes",
                "url": "https://www.runoob.com/sql/sql-tutorial.html",
                "image": "https://static.runoob.com/images/icon/sql.png"
            },
            {
                "title": "Creating Your First Desktop App With HTML, JS and Electron",
                "url": "https://www.runoob.com/js/js-tutorial.html",
                "image": "https://static.runoob.com/images/icon/html.png"
            }
        ]
    },
    computed: {
        // 计算数学，匹配搜索
        filteredArticles: function () {
            var articles_array = this.articles,
                searchString = this.searchString;

            if(!searchString){
                return articles_array;
            }

            searchString = searchString.trim().toLowerCase();

            articles_array = articles_array.filter(function(item){
                if(item.title.toLowerCase().indexOf(searchString) !== -1){
                    return item;
                }
            })

            // 返回过来后的数组
            return articles_array;;
        }
    }
});
</script>
</body>
</html>

切换不同布局实例

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Vue.js 切换不同显示布局</title>
    <script src="https://cdn.staticfile.org/vue/2.4.2/vue.min.js"></script>
    <style>
    /* 隐藏未编译的变量 */

    [v-cloak] {
      display: none;
    }

    *{
    	margin:0;
    	padding:0;
    }

    body{
    	font:15px/1.3 'Open Sans', sans-serif;
    	color: #5e5b64;
    	text-align:center;
    }

    a, a:visited {
    	outline:none;
    	color:#389dc1;
    }

    a:hover{
    	text-decoration:none;
    }

    section, footer, header, aside, nav{
    	display: block;
    }

    /*-------------------------
    	搜索框
    --------------------------*/

    .bar{
    	background-color:#5c9bb7;

    	background-image:-webkit-linear-gradient(top, #5c9bb7, #5392ad);
    	background-image:-moz-linear-gradient(top, #5c9bb7, #5392ad);
    	background-image:linear-gradient(top, #5c9bb7, #5392ad);

    	box-shadow: 0 1px 1px #ccc;
    	border-radius: 2px;
    	 580px;
    	padding: 10px;
    	margin: 45px auto 25px;
    	position:relative;
    	text-align:right;
    	line-height: 1;
    }

    .bar a{
    	background:#4987a1 center center no-repeat;
    	32px;
    	height:32px;
    	display:inline-block;
    	text-decoration:none !important;
    	margin-right:5px;
    	border-radius:2px;
    	cursor:pointer;
    }

    .bar a.active{
    	background-color:#c14694;
    }

    .bar a.list-icon{
    	background-image:url(data:image/png;base64,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);
    }

    .bar a.grid-icon{
    	background-image:url(data:image/png;base64,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);
    }

    .bar input{
    	background:#fff no-repeat 13px 13px;

    	border: none;
    	 100%;
    	line-height: 19px;
    	padding: 11px 0;

    	border-radius: 2px;
    	box-shadow: 0 2px 8px #c4c4c4 inset;
    	text-align: left;
    	font-size: 14px;
    	font-family: inherit;
    	color: #738289;
    	font-weight: bold;
    	outline: none;
    	text-indent: 40px;
    }

    /*-------------------------
    	列表布局
    --------------------------*/

    ul.list{
    	list-style: none;
    	 500px;
    	margin: 0 auto;
    	text-align: left;
    }

    ul.list li{
    	border-bottom: 1px solid #ddd;
    	padding: 10px;
    	overflow: hidden;
    }

    ul.list li img{
    	120px;
    	height:120px;
    	float:left;
    	border:none;
    }

    ul.list li p{
    	margin-left: 135px;
    	font-weight: bold;
    	color:#6e7a7f;
    }

    /*-------------------------
    	网格布局
    --------------------------*/

    ul.grid{
    	list-style: none;
    	 570px;
    	margin: 0 auto;
    	text-align: left;
    }

    ul.grid li{
    	padding: 2px;
    	float:left;
    }

    ul.grid li img{
    	280px;
    	height:280px;
    	object-fit: cover;
    	display:block;
    	border:none;
    }
    </style>

</head>
<body>

<form id="main" v-cloak>

	<div class="bar">

		<!-- 两个按钮用于切换不同的列表布局 -->

		<a class="list-icon" v-bind:class="{ 'active': layout == 'list'}" v-on:click="layout = 'list'"></a>
		<a class="grid-icon" v-bind:class="{ 'active': layout == 'grid'}" v-on:click="layout = 'grid'"></a>
	</div>

	<!-- 我们设置了两套布局页面。使用哪套依赖于 "layout" 绑定 -->

	<ul v-if="layout == 'grid'" class="grid">
		<!-- 使用大图，没有文本 -->
		<li v-for="a in articles">
			<a v-bind:href="a.url" target="_blank"><img v-bind:src="a.image.large" /></a>
		</li>
	</ul>

	<ul v-if="layout == 'list'" class="list">
		<!-- 使用小图及标题 -->
		<li v-for="a in articles">
			<a v-bind:href="a.url" target="_blank"><img v-bind:src="a.image.small" /></a>
			<p>{{a.title}}</p>
		</li>
	</ul>

</form>
<script>

    var demo = new Vue({
    	el: '#main',
    	data: {
            // 视图模型，可能的值是 "grid" 或 "list"。
    		layout: 'grid',

            articles: [{
                "title": "HTML 教程",
                "url": "https://www.runoob.com/html/html-tutorial.html",
                "image": {
                    "large": "https://static.runoob.com/images/mix/htmlbig.png",
                    "small": "https://static.runoob.com/images/icon/html.png"
                }
            },
            {
                "title": "CSS 教程",
                "url": "https://www.runoob.com/css/css-tutorial.html",
                "image": {
                    "large": "https://static.runoob.com/images/mix/cssbig.png",
                    "small": "https://static.runoob.com/images/icon/css.png"
                }
            },
            {
                "title": "JS 教程",
                "url": "https://www.runoob.com/js/js-tutorial.html",
                "image": {
                    "large": "https://static.runoob.com/images/mix/jsbig.jpeg",
                    "small": "https://static.runoob.com/images/icon/js.png"
                }
            },
            {
                "title": "SQL  教程",
                "url": "https://www.runoob.com/sql/sql-tutorial.html",
                "image": {
                    "large": "https://static.runoob.com/images/mix/sqlbig.png",
                    "small": "https://static.runoob.com/images/icon/sql.png"
                }
            },
            {
                "title": "Ajax 教程",
                "url": "https://www.runoob.com/ajax/ajax-tutorial.html",
                "image": {
                    "large": "https://static.runoob.com/images/mix/ajaxbig.png",
                    "small": "https://static.runoob.com/images/icon/ajax.png"
                }
            },
            {
                "title": "Python 教程",
                "url": "https://www.runoob.com/python/python-tutorial.html",
                "image": {
                    "large": "https://static.runoob.com/images/mix/pythonbig.png",
                    "small": "https://static.runoob.com/images/icon/python.png"
                }
            }]

    	}
    });
	
</script>
</body>
</html>