【ant-design】表单validate验证名称重复

 <a-form-item>
                <a-input
                    size="large"
                    type="text"
                    :placeholder="$t('user.register.name.placeholder')"
                    v-decorator="[
                        'name',
                        {
                            validateTrigger: ['change', 'blur'],
                            rules: [
                                { required: true, message: $t('user.email.required') },
                                {
                                    validator: validateToName,
                                    message: '用户名已存在',
                                },
                            ],
                        },
                    ]"
                ></a-input>
            </a-form-item>

 methods: {
        validateToName(rule, value, callback) {
            check({ userName: value }).then((res) => {
                var exist = res.data.exist
                // console.log('ex', exist)
                if (exist) {
                    callback(new Error('名称已存在'))
                } else {
                    callback()
                }
            })
        },
        }