第五章：事件 —— 遥控器的按钮

function RemoteControl() {
  const [temp, setTemp] = useState(26);
  const [isOn, setIsOn] = useState(false);

  const handlePowerPress = () => {
    setIsOn(!isOn);
  };

  return (
    <div>
      <button onClick={handlePowerPress}>
        {isOn ? '关机' : '开机'}
      </button>

      <button onClick={() => setTemp(t => t - 1)}>▼ 降温</button>
      <button onClick={() => setTemp(t => t + 1)}>▲ 升温</button>

      <p>温度: {temp}°C</p>
    </div>
  );
}