搞了个输入框限制字数

结合蚂蚁设计的Antv(类型ElementUi框架)

html部分：

<a-form-item :labelCol="labelCol" :wrapperCol="wrapperCol" label="问题描述">  
 <a-textarea @click.ctrl="countFont" :maxLength="maxLength" :autoFocus="autoFocus" :rows="4" placeholder="请输入问题描述" v-decorator="[ 'retPras', validatorRules.retPras]"/>  
 <span class="tips">还可输入<b :class="{'remnant':this.val.length!=0,'zero':this.val.length==0}">{{remnant}}</b>个字。</span>  
</a-form-item>

data.return部分：

data(){
    return{
        val:'',  
        val2:'',  
        val3:'',  
        maxLength:800,  
        autoFocus:true,
        retPras: {  
          rules: [
          {  
          required: true, 
          message: '请输入问题描述信息!'  
          },
          {  
          validator: this.validateRetPras  
          }]  
        },
        }
}

data.computed部分：

computed: {  
  remnant() {  
  return this.maxLength - this.val.length;  
  },     
},

data.methods部分：

methods: {  
  countFont(){  
  this.maxLength=this.maxLength-20  
  },
  
  validateRetPras(rule, value, callback) {  
  value=value.replace(/[\r\n\]/g,'')  
  if(value&&new RegExp(/^.{0,800}$/).test(value)){  
  this.val=value,  
  callback()  
 }else{  
  callback('请输入有效长度内字数的文字')  
 }},

基本上就这些吧，over!!