特定数组项的setState()

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      items: ['item1', 'item2', 'item3']
    };
  }

  updateItem(index, newValue) {
    this.setState(prevState => {
      const updatedItems = [...prevState.items];
      updatedItems[index] = newValue;
      return { items: updatedItems };
    });
  }

  render() {
    return (
      <div>
        {this.state.items.map((item, index) => (
          <div key={index}>
            {item}
            <button onClick={() => this.updateItem(index, 'new value')}>
              Update
            </button>
          </div>
        ))}
      </div>
    );
  }
}