一、最簡單，通過maxlength和onkeyup
<input maxlength="16" onkeyup="this.value=this.value.replace(/[^\w[!@#.=_~+,./<>?:;'\\\$\%\^\&\*\(\)\-\|\[\]\{\}\{\}]/g,'');" />
代碼中正則是限制除中文外的所有鍵盤字符。
二、通過@input和@change
見代碼：
<input type="text" v-model="groupName" class="edit-input" ref="groupName" @input="changeValue" @change="editGroupNameSave(groupInfo.name)" > changeValue () { let leng = this.validateTextLength(this.groupName) if (leng >= 15) { this.$refs.groupName.maxLength = leng } else { this.$refs.groupName.maxLength = 30 } }, validateTextLength (value) { // 中文、中文標點、全角字符按1長度，英文、英文符號、數字按0.5長度計算 let cnReg = /([\u4e00-\u9fa5]|[\u3000-\u303F]|[\uFF00-\uFF60])/g let mat = value.match(cnReg) let length if (mat) { length = (mat.length + (value.length - mat.length) * 0.5) return length } else { return value.length * 0.5 } }
三、通過watch
見代碼：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Examples</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="" rel="stylesheet">
<script src="https://cdn.bootcss.com/vue/2.4.2/vue.min.js"></script>
</head>
<body>
<div id="app">
<input type="text" v-model="items.text" ref="count"/>
<div v-html="number"></div>
</div>
<script>
new Vue({
el: '#app',
data: {
number: '100',
items: {
text:'',
},
},
watch:{ //watch()監聽某個值（雙向綁定）的變化，從而達到change事件監聽的效果
items:{
handler:function(){
var _this = this;
var _sum = 100; //字體限制為100個
_this.$refs.count.setAttribute("maxlength",_sum);
_this.number= _sum- _this.$refs.count.value.length;
},
deep:true
}
}
})
</script>
</body>
</html>