使用钩子设置状态后运行函数

import React, { useState } from 'react';

const ExampleComponent = () => {
  const [count, setCount] = useState(0);

  const handleSetCount = () => {
    setCount(count + 1); // 设置状态
    printCount(); // 调用函数
  };

  const printCount = () => {
    console.log(`当前count的值为：${count}`);
  };

  return (
    <div>
      <button onClick={handleSetCount}>设置状态</button>
    </div>
  );
};

import React, { useState, useEffect } from 'react';

const ExampleComponent = () => {
  const [data, setData] = useState(null);

  useEffect(() => {
    fetchData(); // 在组件挂载后发送异步请求

    // 在状态更新后执行的函数
    printData();
  }, [data]); // 监听data状态的变化

  const fetchData = async () => {
    const response = await fetch('https://api.example.com/data');
    const data = await response.json();
    setData(data); // 设置状态
  };

  const printData = () => {
    console.log(`当前data的值为：${data}`);
  };

  return (
    <div>
      <button onClick={fetchData}>发送请求</button>
    </div>
  );
};