一、最简单,通过maxlength和onkeyup
<input maxlength="16" onkeyup="this.value=this.value.replace(/[^\w[!@#.=_~+,./<>?:;\'\\\$\%\^\&\*\(\)\-\|\[\]\{\}\{\}]/g,\'\');" />
代码中正则是限制除中文外的所有键盘字符。
二、通过@input和@change
见代码:
<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、中文标点、全角字符按1长度,英文、英文符号、数字按0.5长度计算 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、通过watch
见代码:
<!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()监听某个值(双向绑定)的变化,从而达到change事件监听的效果 items:{ handler:function(){ var _this = this; var _sum = 100; //字体限制为100个 _this.$refs.count.setAttribute("maxlength",_sum); _this.number= _sum- _this.$refs.count.value.length; }, deep:true } } }) </script> </body> </html>