ant-vue input type=number時，max-length長度設置失效

 <a-input
              v-decorator="['customerPhone',{rules: [{required: true, message: '請輸入正確的客戶電話', pattern: '^[0-9]*$'}]}]"
              placeholder="請輸入"
              :maxLength="12"
              />

input類型默認爲text的時候 maxlength纔有效，然後在加下數字校驗