用 v-model 指令在表单控件元素上创建双向数据绑定
v-model 会根据控件类型自动选取正确的方法来更新元素
输入框:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>demo</title>
</head>
<style>
.base{color:#fff}
.pink{background:pink}
</style>
<body>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<div id="demo">
<input type="text" v-model="message" placeholder="请输入。。。">
<p>{{message}}</p>
</div>
<script>
new Vue({
el:'#demo',
data: {
message:"这是输入框"
},
methods:{
}
});
</script>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>demo</title>
</head>
<style>
.base{color:#fff}
.pink{background:pink}
</style>
<body>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<div id="demo">
<input type="text" v-model="message" placeholder="请输入。。。">
<p>{{message}}</p>
<textarea v-model="message2"></textarea>
<p style="white-space:pre">{{message2}}</p>
</div>
<script>
new Vue({
el:'#demo',
data: {
message:"这是输入框",
message2:"这是多行文本框"
},
methods:{
}
});
</script>

复选框
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>demo</title>
</head>
<style>
.base{color:#fff}
.pink{background:pink}
</style>
<body>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<div id="demo">
<input type="checkbox" v-model="checked">{{checked}}
<hr>
<input type="checkbox" v-model="hobby" value="html">html
<input type="checkbox" v-model="hobby" value="css">css
<input type="checkbox" v-model="hobby" value="javascript">javascript
<p>选择的有:{{hobby}}</p>
</div>
<script>
new Vue({
el:'#demo',
data: {
checked:true,
hobby:[]
}
});
</script>

单选按钮
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>demo</title>
</head>
<style>
.base{color:#fff}
.pink{background:pink}
</style>
<body>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<div id="demo">
<input type="radio" name="hobby" id="html" value="html" v-model="checked">
<label for="html">html</label>
<input type="radio" name="hobby" id="css" value="css" v-model="checked">
<label for="css">css</label>
<input type="radio" name="hobby" id="js" value="js" v-model="checked">
<label for="js">js</label>
<hr>
<p>选择的是:{{checked}}</p>
</div>
<script>
new Vue({
el:'#demo',
data: {
checked:"html"
}
});
</script>

select下拉列表
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>demo</title>
</head>
<style>
.base{color:#fff}
.pink{background:pink}
</style>
<body>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<div id="demo">
<select name="" id="" v-model="hobby">
<option value="">请选择</option>
<option value="html">html</option>
<option value="css">css</option>
<option value="js">js</option>
</select>
<hr>
<p>选择的是:{{hobby}}</p>
</div>
<script>
new Vue({
el:'#demo',
data: {
hobby:""
}
});
</script>

在默认情况下, v-model 在 input 事件中同步输入框的值与数据,但你可以添加一个修饰符 lazy ,从而转变为在 change 事件中同步
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>demo</title>
</head>
<style>
.base{color:#fff}
.pink{background:pink}
</style>
<body>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<div id="demo">
<select name="" id="" v-model.lazy="hobby">
<option value="">请选择</option>
<option value="html">html</option>
<option value="css">css</option>
<option value="js">js</option>
</select>
<hr>
<p>选择的是:{{hobby}}</p>
</div>
<script>
new Vue({
el:'#demo',
data: {
hobby:"html"
}
});
</script>
如果想自动将用户的输入值转为 Number 类型(如果原值的转换结果为 NaN 则返回原值),可以添加一个修饰符 number 给 v-model 来处理输入值:
这个很好用,因为在 type="number" 时 HTML 中输入的值也总是会返回字符串类型
<input type="text" v-model.number="text">
如果要自动过滤用户输入的首尾空格,可以添加 trim 修饰符到 v-model 上过滤输入
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>demo</title>
</head>
<style>
.base{color:#fff}
.pink{background:pink}
</style>
<body>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<div id="demo">
过滤空格:
<input type="text" v-model.trim="text">
<p>您输入了:"{{text}}"</p>
<hr>
不过滤空格:
<input type="text" v-model="text2">
<p>您输入了:"{{text2}}"</p>
</div>
<script>
new Vue({
el:'#demo',
data: {
text:"初始数据",
text2:"初始数据"
}
});
</script>

来源:https://www.cnblogs.com/chenyingying0/p/12395397.html