1 插槽slot

componentA： 

<template>
  <h3>ComponentA</h3>
  <ComponentB>
    <div>
      <P>父组件传递的组件</P>
      <p>{
   
   { message }}</p>
    </div>
  </ComponentB>
</template>

<script>
import ComponentB from "./ComponentB.vue"
export default {
  data(){
    return{
      message: "父组件传递的数据"
    }
  },
  components:{
    ComponentB
  }
}
</script>

componentB：

<template>
  <h3>ComponentB</h3>
  <slot>默认值</slot>
</template>

<script>

export default {
  data(){
    return{

    }
  }
}
</script>

2 具名插槽

componentA：

<template>
  <h3>ComponentA</h3>
  <ComponentB>
    <template v-slot:slot1>
      <div>
        <P>父组件传递的组件1</P>
        <p>{
   
   { message }}</p>
      </div>
    </template>
    
    <template v-slot:slot2>
      <div>
        <p>父组件传递的组件2</p>
      </div>
    </template>
  </ComponentB>
</template>

<script>
import ComponentB from "./ComponentB.vue"
export default {
  data(){
    return{
      message: "父组件传递的数据"
    }
  },
  components:{
    ComponentB
  }
}
</script>

componentB：

<template>
  <h3>ComponentB</h3>
  <slot name="slot1">默认值</slot>
  <slot name="slot2">默认值</slot>
</template>

<script>

export default {
  data(){
    return{

    }
  }
}
</script>

如果componentB需要多次插入slot，但是不想重复某些内容，则需要使用<template v-slot:slot1><template>和<slot name="slot1"><slot>两个属性来指定。

3 插槽数据传递

componentA：

<template>
  <h3>ComponentA</h3>
  <ComponentB v-slot="sonData">
    <p>{
   
   { message }}---{
   
   { sonData.msg }}</p>
  </ComponentB>
</template>

<script>
import ComponentB from "./ComponentB.vue"
export default {
  data(){
    return{
      message: "父组件传递的数据"
    }
  },
  components:{
    ComponentB
  }
}
</script>

componentB：

<template>
  <h3>ComponentB</h3>
  <slot :msg="message"></slot>
</template>

<script>

export default {
  data(){
    return{
      message: "子组件传递的数据"
    }
  }
}
</script>

如果父类和子类都要传递数据给插槽，父类直接传递即可，子类需要先传递给父类，父类使用v-slot接收，再将其传递给子类插槽。

4 具名插槽数据传递

 componentA： 

<template>
  <h3>ComponentA</h3>
  <ComponentB>
    <template #header="sonData">
      <p>{
   
   { message }}---{
   
   { sonData.msg }}</p>
    </template>
  </ComponentB>
</template>

<script>
import ComponentB from "./ComponentB.vue"
export default {
  data(){
    return{
      message: "父组件传递的数据"
    }
  },
  components:{
    ComponentB
  }
}
</script>

componentB：

<template>
  <h3>ComponentB</h3>
  <slot name="header" :msg="message"></slot>
</template>

<script>

export default {
  data(){
    return{
      message: "子组件传递的数据"
    }
  }
}
</script>

5 组件切换&保持存活

App：

<template>
  <keep-alive>
    <component :is="tabComponent"></component>
  </keep-alive>
  <button @click="changeComponent">切换组件</button>
</template>

<script>
import {defineComponent} from "vue";

import ComponentA from "./components/ComponentA.vue"
import ComponentC from "./components/ComponentC.vue"
import ComponentD from "./components/ComponentD.vue"
export default defineComponent({
  data(){
    return{
      tabComponent: "ComponentC"
    }
  },
  components:{
    ComponentA,
    ComponentC,
    ComponentD
  },
  methods:{
    changeComponent(){
      this.tabComponent = this.tabComponent === "ComponentC" ? "ComponentD" : "ComponentC"
    }
  }
})
</script>

ComponentC：

<template>
  <h3>ComponentC</h3>
  <p>{
   
   { message }}</p>
  <button @click="changeData">改变数据</button>
</template>

<script>
export default {
  data(){
    return{
      message: "old"
    }
  },
  methods:{
    changeData(){
      this.message = "new"
    }
  }
}
</script>

ComponentD：

<template>
  <h3>ComponentD</h3>
</template>

<script setup>

</script>

6 异步加载组件

只需要修改App：

<template>
  <keep-alive>
    <component :is="tabComponent"></component>
  </keep-alive>
  <button @click="changeComponent">切换组件</button>
</template>

<script>
import {defineAsyncComponent, defineComponent} from "vue";

import ComponentA from "./components/ComponentA.vue"
import ComponentC from "./components/ComponentC.vue"
// 异步加载组件
const ComponentD = defineAsyncComponent(() =>
  import("./components/ComponentD.vue")
)
export default defineComponent({
  data(){
    return{
      tabComponent: "ComponentC"
    }
  },
  components:{
    ComponentA,
    ComponentC,
    ComponentD
  },
  methods:{
    changeComponent(){
      this.tabComponent = this.tabComponent === "ComponentC" ? "ComponentD" : "ComponentC"
    }
  }
})
</script>

7 注入依赖

在有多级继承组件时，最底层组件想要访问最顶层组件的数据，如果通过props实现，需要一层一层传递，会很麻烦。所以，这种情况可以使用provide和inject配合实现。