vue Element验证input提示

        <el-form-item prop="userName" class="userName_color">
            <b>详细地址<i class="red">*</i></b>
              <el-input 
                  placeholder="请填写详细地址"  
                  v-model="loginRuleForm.userName" 
                  class="Channel_account"
                  maxlength="18"
              ></el-input>
          </el-form-item>    

           loginRuleForm: {
                    userName: ''
                },
                rules: {
                    userName: [
                        {required: true, message: "统一社会信用代码不能为空" ,trigger: 'blur'},
                    ]
                },