输入框校验：只能输入中文

//js文件
validate: function() {
            var reg = /^[\u4e00-\u9fa5]+$/;
            
            if(reg.test(this.coupletUp)&&reg.test(this.coupletDown))
            {
                this.error=false;
                this.errorText="";
                this.isdisabled=false;
                return true;

            }
            this.error=true;
            this.errorText="请输入汉字";
            this.isdisabled=true;
            return false;
        },
        /**
         * 上传编辑后春联内容
         */
coupletConfirm() {
            const status = this.validate() 
            if (status) {       
                this.renderData.springScrolls.L = this.coupletUp;
                this.renderData.springScrolls.R = this.coupletDown; 
                this.inputImageModal=false;
            }
        },

<!--wxml文件-->
       <div class="couplet-up">
       <div class="couplet-label">上联：</div>
       <div class="couplet-content"><input class="couplet-text" placeholder="最多输入七个字" maxlength="7" v-model="coupletUp" @blur="validate"></div>                    
       </div>
       <div class="couplet-down">
       <div class="couplet-label">下联：</div>
       <div class="couplet-content"><input class="couplet-text" placeholder="最多输入七个字" maxlength="7" v-model="coupletDown" @blur="validate"></div>                    
        </div>
        <div class="error_tip">
              <span v-if="error">{{errorText}}</span>
        </div>
        <button class="couplet-confirm" :class="isdisabled?btndisabled:''" @tap="coupletConfirm" :disabled="isdisabled">确定</button>