1. 在父组件中

import React, { Component } from "react";
import Child from './child'
class Parent extends Component {
  constructor(props) {
    super(props);
    this.state = {
      top: "--------------- 上 --------------------",
      bottom: "--------------- 下 --------------------",
      defaultContent: "默认插槽内容",
      namedContent: "具名插槽内容",
    };
  }
  render() {
    return (
      <>
        <h1>react 插槽</h1>
        <div>{this.state.top}</div>
        <Child namedSlot={<div>{this.state.namedContent}</div>}>  {/* 具名插槽 */}
          <div>{this.state.defaultContent}</div>  {/* 默认插槽 */}
        </Child>
        <div>{this.state.bottom}</div>
      </>
    );
  }
}
export default Parent;

2. 在子组件中

import React, { Component } from "react";
class Child extends Component {
  constructor(props) {
    super(props);
    this.state = {};
  }
  render() {
    return (
      <>
        <div>{this.props.children}</div>  {/* 定义默认插槽位置 */}
        <div>{this.props.namedSlot}</div>  {/* 定义具名插槽位置 */}
      </>
    );
  }
}
export default Child;