关于更改返回的有效负载的React reducer问题

import React, { useReducer } from 'react';

const initialState = {
  count: 0,
  message: 'Hello World'
};

const reducer = (state, action) => {
  switch (action.type) {
    case 'increment':
      return { ...state, count: state.count + 1 };
    case 'decrement':
      return { ...state, count: state.count - 1 };
    case 'setMessage':
      return { ...state, message: action.payload };
    default:
      return state;
  }
};

const Counter = () => {
  const [state, dispatch] = useReducer(reducer, initialState);

  const handleIncrement = () => {
    dispatch({ type: 'increment' });
  };

  const handleDecrement = () => {
    dispatch({ type: 'decrement' });
  };

  const handleMessageChange = (e) => {
    dispatch({ type: 'setMessage', payload: e.target.value });
  };

  return (
    <div>
      <p>Count: {state.count}</p>
      <button onClick={handleIncrement}>Increment</button>
      <button onClick={handleDecrement}>Decrement</button>
      <input type="text" value={state.message} onChange={handleMessageChange} />
    </div>
  );
};

export default Counter;