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Detailed explanation of the use of form controls in Vue.js

php中世界最好的语言Original: 2018-04-28 09:21:411444browse

This time I will bring you a detailed explanation of the use of Vue.js form controls. What are the precautions when using Vue.js form controls? Here are practical cases, let’s take a look.

Concept Description

v-model directive: Creates a two-way data binding on a form control element. v-model will automatically choose the correct method to update the element based on the control type.

Input box

The example demonstrates the use of v-model in the input and textarea elements to achieve bidirectionality Data binding:

HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Vue 测试实例</title>
<script src="https://cdn.bootcss.com/vue/2.2.2/vue.min.js"></script>
</head>
<body>
<p id="app">
 <p>input 元素：</p>
 <input v-model="message" placeholder="编辑我……">
 <p>消息是: {{ message }}</p>
 <p>textarea 元素：</p>
 <p style="white-space: pre">{{ message2 }}</p>
 <textarea v-model="message2" placeholder="多行文本输入……"></textarea>
</p>
<script>
new Vue({
 el: '#app',
 data: {
 message: 'Runoob',
 message2: '菜鸟教程\r\nhttp://www.runoob.com'
 }
})
</script>
</body>
</html>

The effect is as shown in the figure:

Complex Check box

If the check box is a single one, it is a logical value. If there are multiple check boxes, it is bound to the same array:

HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Vue 测试实例 - 菜鸟教程(runoob.com)</title>
<script src="https://cdn.bootcss.com/vue/2.2.2/vue.min.js"></script>
</head>
<body>
<p id="app">
 <p>单个复选框：</p>
 <input type="checkbox" id="checkbox" v-model="checked">
 <label for="checkbox">{{ checked }}</label>
 <p>多个复选框：</p>
 <input type="checkbox" id="runoob" value="Runoob" v-model="checkedNames">
 <label for="runoob">Runoob</label>
 <input type="checkbox" id="google" value="Google" v-model="checkedNames">
 <label for="google">Google</label>
 <input type="checkbox" id="taobao" value="Taobao" v-model="checkedNames">
 <label for="taobao">taobao</label>
 <br>
 <span>选择的值为: {{ checkedNames }}</span>
</p>
<script>
new Vue({
 el: '#app',
 data: {
 checked : false,
 checkedNames: []
 }
})
</script>
</body>
</html>

The effect is as shown:

Radio button

##HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Vue 测试实例 - 菜鸟教程(runoob.com)</title>
<script src="https://cdn.bootcss.com/vue/2.2.2/vue.min.js"></script>
</head>
<body>
<p id="app">
 <input type="radio" id="runoob" value="Runoob" v-model="picked">
 <label for="runoob">Runoob</label>
 <br>
 <input type="radio" id="google" value="Google" v-model="picked">
 <label for="google">Google</label>
 <br>
 <span>选中值为: {{ picked }}</span>
</p>
<script>
new Vue({
 el: '#app',
 data: {
 picked : 'Runoob'
 }
})
</script>
</body>
</html>

The effect is as shown:

##Drop-down list

HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Vue 测试实例 - 菜鸟教程(runoob.com)</title>
<script src="https://cdn.bootcss.com/vue/2.2.2/vue.min.js"></script>
</head>
<body>
<p id="app">
 <select v-model="selected" name="fruit">
 <option value="">选择一个网站</option>
 <option value="www.runoob.com">Runoob</option>
 <option value="www.google.com">Google</option>
 </select>
 <p id="output">
 选择的网站是: {{selected}}
 </p>
</p>
<script>
new Vue({
 el: '#app',
 data: {
 selected: '' 
 }
})
</script>
</body>
</html>

The effect is as shown:

Modifier.lazy

By default, v-model synchronizes the value and data of the input box in the input event, but you can add a modifier lazy , thus changing to synchronization in the change event:

<!-- 在 "change" 而不是 "input" 事件中更新 -->
<input v-model.lazy="msg" >

.number

If you want to automatically convert the user's input value to the Number type (if the conversion result of the original value is NaN, return the original value ), you can add a modifier number to v-model to process the input value:

<input v-model.number="age" type="number">

This is usually useful, because the value entered in HTML will always return a string type when type="number" .

.trim

If you want to

automatically filter

the first and last spaces entered by the user, you can add the trim modifier to v-model to filter the input:

<input v-model.trim="msg">

I believe I read it You have mastered the method in the case of this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

Detailed explanation of the use of form controls in Vue.js

Concept Description

Input box

Complex Check box

Radio button

##Drop-down list

Modifier.lazy

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