如何使用Vue表单处理实现表单的状态管理

<template>
  <div>
    <input type="text" v-model="username" />
    <p>用户名：{{ username }}</p><p><span>立即学习</span>“<a href="https://pan.quark.cn/s/cb6835dc7db1" style="text-decoration: underline !important; color: blue; font-weight: bolder;" rel="nofollow" target="_blank">前端免费学习笔记（深入）</a>”；</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      username: ''
    }
  }
}
</script>

<template>
  <div>
    <input type="text" v-model="username" />
    <span v-if="!validUsername">用户名格式不正确</span>
    <button @click="submit">提交</button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      username: ''
    }
  },
  computed: {
    validUsername() {
      // 校验逻辑，返回true或false
      // 比如：用户名必须为3-10位字母或数字
      const reg = /^[A-Za-z0-9]{3,10}$/
      return reg.test(this.username)
    }
  },
  methods: {
    submit() {
      if (this.validUsername) {
        // 校验通过，执行提交操作
        // ...
      }
    }
  }
}
</script>

<template>
  <div>
    <InputField v-model="username" :validator="validUsername" label="用户名" />
    <span v-if="!validUsername">用户名格式不正确</span>
    <SubmitButton :disabled="!validUsername" @submit="submit" />
  </div>
</template>

<script>
import InputField from './InputField.vue'
import SubmitButton from './SubmitButton.vue'

export default {
  components: {
    InputField,
    SubmitButton
  },
  data() {
    return {
      username: ''
    }
  },
  computed: {
    validUsername() {
      const reg = /^[A-Za-z0-9]{3,10}$/
      return reg.test(this.username)
    }
  },
  methods: {
    submit() {
      // 执行提交操作
      // ...
    }
  }
}
</script>