Vue 组件之间的通信方式详解

<!-- 父组件 -->
<template>
  <div>
    <child-component :message="parentMessage"></child-component>
  </div>
</template>
<script>
import ChildComponent from './ChildComponent.vue';
export default {
  components: {
    ChildComponent
  },
  data() {
    return {
      parentMessage: 'Hello from Parent!'
    };
  }
};
</script>

<!-- 子组件 -->
<template>
  <div>
    <p>{{ message }}</p>
  </div>
</template>
<script>
export default {
  props: ['message']
};
</script>

<!-- 子组件 -->
<template>
  <div>
    <button @click="sendMessage">Send Message</button>
  </div>
</template>
<script>
export default {
  methods: {
    sendMessage() {
      this.$emit('message-sent', 'Hello from Child!');
    }
  }
};
</script>

<!-- 父组件 -->
<template>
  <div>
    <child-component @message-sent="handleMessage"></child-component>
  </div>
</template>
<script>
import ChildComponent from './ChildComponent.vue';
export default {
  components: {
    ChildComponent
  },
  methods: {
    handleMessage(message) {
      console.log(message);  // 输出 'Hello from Child!'
    }
  }
};
</script>

// event-bus.js
import Vue from 'vue';
export const EventBus = new Vue();

<!-- 组件 A -->
<template>
  <div>
    <button @click="sendMessage">Send Message</button>
  </div>
</template>
<script>
import { EventBus } from './event-bus.js';
export default {
  methods: {
    sendMessage() {
      EventBus.$emit('message-sent', 'Hello from Component A!');
    }
  }
};
</script>
<!-- 组件 B -->
<template>
  <div>
    <p>{{ message }}</p>
  </div>
</template>
<script>
import { EventBus } from './event-bus.js';
export default {
  data() {
    return {
      message: ''
    };
  },
  created() {
    EventBus.$on('message-sent', (message) => {
      this.message = message;
    });
  }
};
</script>

// store.js
import Vue from 'vue';
import Vuex from 'vuex';
Vue.use(Vuex);
export default new Vuex.Store({
  state: {
    message: ''
  },
  mutations: {
    setMessage(state, message) {
      state.message = message;
    }
  },
  actions: {
    updateMessage({ commit }, message) {
      commit('setMessage', message);
    }
  }
});

<!-- 组件 A -->
<template>
  <div>
    <button @click="sendMessage">Send Message</button>
  </div>
</template>
<script>
export default {
  methods: {
    sendMessage() {
      this.$store.dispatch('updateMessage', 'Hello from Component A!');
    }
  }
};
</script>
<!-- 组件 B -->
<template>
  <div>
    <p>{{ message }}</p>
  </div>
</template>
<script>
export default {
  computed: {
    message() {
      return this.$store.state.message;
    }
  }
};
</script>