html
              
              
            
          
          // parent.vue
<Myinput
  v-model="keyWords"
  placeholder="请输入内容"
  size="small"
  @input="input"
  @change="change"
  width="320"
>
  <template #prepend>
    <el-select v-model="select" placeholder="请选择" style="width: 115px">
      <el-option label="Restaurant" value="1" />
      <el-option label="Order No." value="2" />
      <el-option label="Tel" value="3" />
    </el-select>
  </template>
  <template #append>
    <el-button @click="handleQuery">查询</el-button>
  </template>
</Myinput>
// child.vue
  <el-input
    v-bind="$attrs"
    class="e-input"
    :style="inputStyle"
    v-on="$listeners"
    @input="$emit('input', $event)"
    @change="$emit('change', $event)"
  >
    <template v-for="(_, slotName) in $slots" #[slotName]>
      <slot :name="slotName"></slot>
    </template>
  </el-input>内部属性: $attrs、$listeners、$slots一、属性的透传
v-bind="$attrs": 只会读取子组件【props 选项】中没有申明过的属性
二、自定义事件的透传
方式一:
v-on="$listeners": 会将父组件所有事件监听器传递到子组件内部元素
            
            
              html
              
              
            
          
          <el-input 
    v-bind="$attrs" 
    class="e-input" 
    :style="inputStyle" 
    v-on="$listeners">
</el-input>方式二: 直接在子组件上触发事件
            
            
              html
              
              
            
          
          <el-input
  v-bind="$attrs"
  class="e-input"
  :style="inputStyle"
  @input="$emit('input', $event)"
  @change="$emit('change', $event)"
>
</el-input>方式三: 手动触发事件
            
            
              js
              
              
            
          
          export default {
  props: ["value"],
  computed: {
    inputValue: {
      get() {
        return this.value;
      },
      set(val) {
        this.$emit("input", val);
      },
    },
  },
  methods: {
    handleChange(e) {
      this.$emit("change", e.target.value);
    },
  },
};三、插槽的透传
"$slots": 获取所有父组件传递的插槽(默认、具名、作用域)
            
            
              html
              
              
            
          
          <template v-for="(_, slotName) in $slots" #[slotName]>
  <slot :name="slotName"></slot>
</template>四、获取子组件实例
            
            
              js
              
              
            
          
          // parent.vue
<Myinput ref="elInp" />
  mounted() {
    // 输入框聚焦
    this.$refs.elInp.setFocus();
  },
            
            
              html
              
              
            
          
          //child.vue
    <el-input
      ref="inputRef"
      v-bind="$attrs"
      class="e-input"
      :style="inputStyle"
      v-on="$listeners"
    />
    
methods: {
    setFocus() {
      this.$refs.inputRef.focus();
    },
},