abstrak：<!DOCTYPE html><html><head> <meta charset="UTF-8"> <title>偵聽(tīng)器</title></head><body><div id="box">&nbs
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>偵聽(tīng)器</title>
</head>
<body>
<div id="box">
用戶名:<input type="text" v-model="username"> <br>
<h3>{{length}}</h3>
<h3 v-show="isShow" :style="warning">{{message}}</h3>
</div>
<script src="js/vue.js"></script>
<script>
new Vue({
el: '#box',
data: {
username: '',
length: 0,
message: '用戶名太短',
isShow: false,
warning: 'color:red'
},
// 偵聽(tīng)器:實(shí)時(shí)監(jiān)測(cè)頁(yè)面中數(shù)據(jù)的變化,實(shí)時(shí)更新數(shù)據(jù)模型中的屬性,并完成指定的動(dòng)作
watch: {
// Vue是面向數(shù)據(jù)編程,偵聽(tīng)器當(dāng)然也是面數(shù)據(jù),所以watch中偵聽(tīng)的屬性必須是頁(yè)面中的變量
username: function () {
this.length++;
if (this.length < 6) {
this.isShow = true;
} else {
this.isShow = false;
}
}
}
});
</script>
</body>
</html>
Guru membetulkan：天蓬老師Masa pembetulan：2018-12-29 10:23:59
Rumusan guru：學(xué)習(xí)vue,一定要把它的mvvm模式搞清楚,就快多了