Vue3实现双向绑定的基本原理和代码示例解析

<template>
  <div>
    <h1>Vue3 双向绑定示例</h1>
    <!-- 使用v-model进行双向绑定 -->
    <CustomInput v-model="inputValue" />
    <p>父组件中的值：{{ inputValue }}</p>
  </div>
</template>
<script>
import CustomInput from './CustomInput.vue';
export default {
  components: { CustomInput },
  data() {
    return {
      inputValue: '' // 父组件的数据
    };
  }
};
</script>

<template>
  <div>
    <!-- 子组件接受父组件传递的值 -->
    <input :value="modelValue" @input="onInput" />
  </div>
</template>
<script>
export default {
  props: {
    // 接收父组件传递的值
    modelValue: {
      type: String,
      required: true
    }
  },
  methods: {
    // 触发事件将数据回传给父组件
    onInput(event) {
      this.$emit('update:modelValue', event.target.value);
    }
  }
};
</script>

:modelValue="inputValue" @update:modelValue="value => inputValue = value"

// 定义响应式对象
function reactive(target) {
  return new Proxy(target, {
    get(target, key, receiver) {
      console.log(`访问属性: ${key}`);
      return Reflect.get(target, key, receiver);
    },
    set(target, key, value, receiver) {
      console.log(`设置属性: ${key} 为 ${value}`);
      const result = Reflect.set(target, key, value, receiver);
      // 响应式触发视图更新
      triggerUpdate();
      return result;
    }
  });
}
function triggerUpdate() {
  console.log('视图更新');
}
// 示例
const state = reactive({ name: 'Vue3', count: 0 });
console.log(state.name); // 访问属性: name
state.count++; // 设置属性: count 为 1，触发视图更新

<CustomInput v-model:title="titleValue" />

:Title="titleValue" @update:Title="value => titleValue = value"

<script>
export default {
  props: {
    title: {
      type: String,
      required: true
    }
  },
  methods: {
    onInput(event) {
      this.$emit('update:title', event.target.value);
    }
  }
};
</script>