Nit*_*mar 15 javascript vue.js vuejs2
我正在努力学习vue.js. 我正在添加元素列表,我想class="active"只添加到for循环中的第一个元素.以下是我的代码:
<div class="carousel-inner text-center " role="listbox">
<div class="item" v-for="sliderContent in sliderContents">
<h1>{{ sliderContent.title }}</h1>
<p v-html="sliderContent.paragraph"></p>
</div>
</div>
所以第一个元素应该是这样的:
<div class="item active">
<h1>WELCOME TO CANVAS</h1>
<p>Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas</p>
</div>
我能够获取数据,所以一切都运行得很好.
以下是我的脚本代码:
<script>
export default{
data() {
return {
sliderContents: [
{
title: "WELCOME TO CANVAS",
paragraph: "Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas"
},
{
title: "WELCOME TO CANVAS",
paragraph: "Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas"
},
{
title: "WELCOME TO CANVAS",
paragraph: "Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas"
},
{
title: "WELCOME TO CANVAS",
paragraph: "Create just what you need for your Perfect Website. Choose from a wide<br>range of Elements & simple put them on your own Canvas"
}
]
}
}
}
帮帮我.
Win*_*ing 32
const TextComponent = {
template: `
<p>{{ text }}</p>
`,
props: ['text'],
};
new Vue({
components: {
TextComponent,
},
template: `
<div>
<text-component
v-for="(item, index) in items"
:class="{ 'active': index === 0 }"
:text="item.text">
</text-component>
</div>
`,
data: {
items: [
{ text: 'Foo' },
{ text: 'Bar' },
{ text: 'Baz' },
],
},
}).$mount('#app');.active {
background-color: red;
}<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title></title>
</head>
<body>
<div id="app"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.0.3/vue.js"></script>
</body>
</html>以上是演示解决问题的片段.这是一个概述:
在内部
v-for块中,我们可以完全访问父作用域属性.v-for还支持当前项的索引的可选第二个参数.
- https://vuejs.org/v2/guide/list.html#Basic-Usage
该v-for指令有第二个参数,为您提供项目的索引.
v-for="(item, index) in items"
由于您希望active第一个项目上的类,您可以使用表达式测试,如果index是,0并将其绑定到类属性.
:class="{ 'active': index === 0 }"
最简单的解决方案是检查每个元素是否index等于0，然后设置active类（或所需的类）。这是类定义的代码：
:class="{ 'active': index === 0 }"
这是制作的工作示例Bootstrap Tabs：
<ul class="nav nav-tabs tab-nav-right" role="tablist">
<li role="presentation" :class="{ 'active': index === 0 }" v-for="(value, index) in some_array" v-bind:key="index">
{{some_array[index]}}
</li>
</ul>
另外，如果您有多个课程，可以像这样混合使用：
:class="['tab-pane fade', (index === 0 ? 'active in' : 'something_else')]"