表单类组件封装&v-model简化代码

创建 工程：
H:\java_work\java_springboot\vue_study

ctrl按住不放 右键 悬着 powershell

H:\java_work\java_springboot\js_study\Vue2_3入门到实战-配套资料\01-随堂代码素材\day04\准备代码\11-封装表单类组件

vue --version

vue create v-fengzhuang-demo
cd v-fengzhuang-demo
npm run serve

App.vue

<template class="app">
  <BaseSelect :cityId="selectId" @changeId="selectId = $event"> </BaseSelect>
</template>

<script>
import BaseSelect from "./components/BaseSelect.vue";

export default {
  data() {
    return {
      selectId: "103",
    };
  },
  components: {
    BaseSelect,
  },
};
</script>

<style>
</style>

components\BaseSelect.vue

<template>
  <div>
    <select :value="cityId" @change="handleChange">
      <option value="101">北京</option>
      <option value="102">上海</option>
      <option value="103">武汉</option>
      <option value="104">深圳</option>
      <option value="105">广州</option>
    </select>
  </div>
</template>

<script>
export default {
  props: {
    cityId: String,
  },
  methods: {
    handleChange(e) {
      // console.log(e.target.value);
      this.$emit("changeId", e.target.value);
    },
  },
};
</script>

<style>
</style>

App.vue

<template class="app">
  <!-- <BaseSelect :value="selectId" @input="selectId = $event"> </BaseSelect> -->
  <div>
    <BaseSelect v-model="selectId"></BaseSelect>
    <BaseSelect :value="selectId" @input="selectId = $event"> </BaseSelect>
  </div>
</template>

<script>
import BaseSelect from "./components/BaseSelect.vue";

export default {
  data() {
    return {
      selectId: "103",
    };
  },
  components: {
    BaseSelect,
  },
};
</script>

<style>
</style>

components\BaseSelect.vue

<template>
  <div>
    <select :value="value" @change="handleChange">
      <option value="101">北京</option>
      <option value="102">上海</option>
      <option value="103">武汉</option>
      <option value="104">深圳</option>
      <option value="105">广州</option>
    </select>
  </div>
</template>

<script>
export default {
  props: {
    value: String,
  },
  methods: {
    handleChange(e) {
      // console.log(e.target.value);
      this.$emit("input", e.target.value);
    },
  },
};
</script>

<style>
</style>