v-text
v-text is mainly used to update textContent, which can be equivalent to the text attribute of JS.
<span v-text="text"></span> // 等同于下方语句: <span>{{text}}</span>
v-html
The double brace method will interpret the data as plain text, not HTML. In order to output real HTML, you can use the v-html command. It is equivalent to JS's innerHtml property.
Note: Content is inserted as normal HTML - will not be compiled as a Vue template.
<div v-html="html"></div>
v-show
Equivalent to css's dispaly attribute switching between "none" and "block" settings.
<div v-show="isShow">hello world</div>
v-if
v-if can implement conditional rendering. Vue will render elements based on the true and false conditions of the expression value. .
<div v-show="isShow">hello world</div>
The above code, if isShow is false, the div is rendered, otherwise it is not rendered.
Note:
v-if needs to be distinguished from v-show. The elements of v-show will always be rendered and saved in the dom. It just simply switches the dispaly attribute of css.
v-if has higher switching overhead.
v-show has higher initial rendering overhead.
So, if you want to switch very frequently, it is better to use v-show; if the conditions are unlikely to change during runtime, it is better to use v-if.
v-else
v-else is used with v-if, it must follow v-if or v-else -if after, otherwise it has no effect.
Similar to JS’s if .. else.
<div v-if="isSow">值为true的时候显示的内容</div> <div v-else>值为false的时候显示的内容</div>
v-else-if
v-else-if acts as the else-if block of v-if and can be used in a chain repeatedly. Similar to JS's if .. else if .. else
<div v-if="type==='A'"> A </div> <div v-if="type==='B'"> B </div> <div v-if="type==='C'"> C </div> <div v-else> Not A,B,C </div>
v-for
Use the v-for instruction to render by traversing the array .
<ul> <li v-for="item in items">{{item.name}}</li> </ul> <script> new Vue({ el: '#app', data: { items: [ { name: 'Runoob' }, { name: 'Google' }, { name: 'Taobao' } ] } }) </script> // 补充: // 也可以自行指定参数,最多可以接受3个参数 <div v-for="(item, index) in items"></div> <div v-for="(val, key) in object"></div> <div v-for="(val, name, index) in object"></div> // 迭代对象 <ul> <li v-for="value in object"> {{ index }}. {{ key }} : {{ value }} </li> // 迭代整数 <ul> <li v-for="n in 10"> {{ n }} </li> </ul>
v-on
Bind event listener. The event type is specified by parameters. The expression can be the name of a method or an inline statement, and can be omitted if there are no modifiers.
v-on can also be abbreviated as "@", such as:
v-on="show" can be abbreviated as: @show
<!-- 方法处理器 --> <button v-on:click="doThis"></button> <!-- 动态事件 (2.6.0+) --> <button v-on:[event]="doThis"></button> <!-- 内联语句 --> <button v-on:click="doThat('hello', $event)"></button> <!-- 缩写 --> <button @click="doThis"></button> <!-- 动态事件缩写 (2.6.0+) --> <button @[event]="doThis"></button> <!-- 停止冒泡 --> <button @click.stop="doThis"></button> <!-- 阻止默认行为 --> <button @click.prevent="doThis"></button> <!-- 阻止默认行为,没有表达式 --> <form @submit.prevent></form> <!-- 串联修饰符 --> <button @click.stop.prevent="doThis"></button> <!-- 键修饰符,键别名 --> <input @keyup.enter="onEnter"> <!-- 键修饰符,键代码 --> <input @keyup.13="onEnter"> <!-- 点击回调只会触发一次 --> <button v-on:click.once="doThis"></button> <!-- 对象语法 (2.4.0+) --> <button v-on="{ mousedown: doThis, mouseup: doThat }"></button>
You can also use modifiers, as follows :
.stop - Call event.stopPropagation().
.prevent - Calls event.preventDefault().
.capture - Use capture mode when adding event listeners.
.self - The callback is only triggered when the event is triggered from the element itself to which the listener is bound.
.{keyCode | keyAlias} - The callback is only fired when the event is triggered from a specific key.
.native - Listen to native events on the root element of the component.
.once - The callback is triggered only once.
.left - only fires when the left mouse button is clicked.
.right - only triggered when the right mouse button is clicked.
.middle - only triggered when the middle mouse button is clicked.
.passive - add a listener in { passive: true } mode
v-bind
Dynamically bind one or more attributes, or a component prop to an expression. Often used to dynamically bind classes and styles. And href etc.
can be abbreviated as: " : ", such as:
v-bind:class=" isActive : 'active' :' ' ", can be abbreviated as: :class=" isActive : ' active' :' ' "
<div v-bind:class=" isActive : 'active' :' ' "></div> <script> var app = new Vue({ el: '#app', data: { isActive : true, } }) </script> //渲染结果为: <div class="active"></div>
Bind multiple classes, the details are as follows:
<div v-bind:class="[ isActive : 'active' :' ' , isError: 'error' :' ' ]"> </div> <script> var app = new Vue({ el: '#app', data: { isActive : true, isError: true, } }) </script> //渲染结果为: <div class="active error"></div>
Other examples, see the code below for details:
<!-- 绑定一个属性 --> <img v-bind:src="imageSrc"> <!-- 动态特性名 (2.6.0+) --> <button v-bind:[key]="value"></button> <!-- 缩写 --> <img :src="imageSrc"> <!-- 动态特性名缩写 (2.6.0+) --> <button :[key]="value"></button> <!-- 内联字符串拼接 --> <img :src="'/path/to/images/' + fileName"> <!-- class 绑定 --> <div :class="{ red: isRed }"></div> <div :class="[classA, classB]"></div> <div :class="[classA, { classB: isB, classC: isC }]"> <!-- style 绑定 --> <div :style="{ fontSize: size + 'px' }"></div> <div :style="[styleObjectA, styleObjectB]"></div> <!-- 绑定一个有属性的对象 --> <div v-bind="{ id: someProp, 'other-attr': otherProp }"></div> <!-- 通过 prop 修饰符绑定 DOM 属性 --> <div v-bind:text-content.prop="text"></div> <!-- prop 绑定。“prop”必须在 my-component 中声明。--> <my-component :prop="someThing"></my-component> <!-- 通过 $props 将父组件的 props 一起传给子组件 --> <child-component v-bind="$props"></child-component> <!-- XLink --> <svg><a :xlink:special="foo"></a></svg>
v-model
#Create two-way binding on a form control or component.
v-model will ignore the initial values of the value, checked, and selected attributes of all form elements. Because it selects Vue instance data as the specific value.
<div id="app"> <input v-model="somebody"> <p>hello {{somebody}}</p> </div> <script> var app = new Vue({ el: '#app', data: { somebody:'小明' } }) </script>
In this example, enter another name directly into the browser input, and the content of the p below will change directly accordingly. This is two-way data binding.
Available modifiers:
.lazy - By default, v-model synchronizes the value and data of the input box. You can use this modifier to switch to resynchronization in the change event.
.number - Automatically convert the user's input value into a numerical type
.trim - Automatically filter the leading and trailing spaces entered by the user
How to use modifiers: For example:
<input v-model.trim="somebody">
v-pre
v-pre is mainly used to skip the compilation process of this element and its sub-elements. Can be used to display the original Mustache tag. Skip a large number of nodes without instructions to speed up compilation.
<div id="app"> <span v-pre>{{message}}</span> //这条语句不进行编译 <span>{{message}}</span> </div>
This directive is used to remain on the element until the end of the associated instance for compilation.
<div id="app" v-cloak> <div> {{message}} </div> </div> <script type="text/javascript"> new Vue({ el:'#app', data:{ message:'hello world' } }) </script>
Explanation:
will flash when the page is loaded. It will first display:
<div> {{message}} </div>
and then compile to:
<div> hello world! </div>
The v-cloak command can To solve the problem of interpolation flickering above, as follows: In fact, what is used is to hide the content through the style attribute when the interpolation is not loaded.
<style> [v-cloak] { display: none; } </style> <div id="app"> <!-- 使用 v-cloak 能够解决 插值表达式闪烁的问题 --> <p v-cloak>++++++++ {{ msg }} ----------</p> </div> <script> var vm = new Vue({ el: '#app', data: { msg: 'hello', } }) </script>
v-once
v-once关联的实例,只会渲染一次。之后的重新渲染,实例极其所有的子节点将被视为静态内容跳过,这可以用于优化更新性能。
<span v-once>This will never change:{{msg}}</span> //单个元素 <div v-once>//有子元素 <h1>comment</h1> <p>{{msg}}</p> </div> <my-component v-once:comment="msg"></my-component> //组件 <ul> <li v-for="i in list">{{i}}</li> </ul>
上面的例子中,msg,list即使产生改变,也不会重新渲染。
v-slot
提供具名插槽或需要接收 prop 的插槽。
可简写为:#
slot 和 scope-slot 是在 vue@2.6.x 之前的语法,而从 vue@2.6.0 开始,官方推荐我们使用 v-slot 来替代前两者。
使用具名插槽来自定义模板内容(vue@2.6.x已经废弃)
<div class="container"> <header> <slot name="header"></slot> </header> <main> <slot></slot> </main> <footer> <slot name="footer"></slot> </footer> </div>
在向具名插槽提供内容的时候,我们可以在一个父组件的 元素上使用 slot 特性:
<base-layout> <template slot="header"> <h1>Here might be a page title</h1> </template> <p>A paragraph for the main content.</p> <p>And another one.</p> <template slot="footer"> <p>Here's some contact info</p> </template> </base-layout>
接下来,使用 v-slot 指令改写上面的栗子:
<base-layout> <template v-slot:header> <h1>Here might be a page title</h1> </template> <p>A paragraph for the main content.</p> <p>And another one.</p> <template v-slot:footer> <p>Here's some contact info</p> </template> </base-layout>
使用 # 简写代替 v-slot
<base-layout> <template #header> <h1>Here might be a page title</h1> </template> <p>A paragraph for the main content.</p> <p>And another one.</p> <template #footer> <p>Here's some contact info</p> </template> </base-layout>
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