计数增量器未在反应钩子中设置状态

Question

我有一个Meal组件的列表，我在MealList组件中渲染这些组件。对于每顿饭，我想传递一个计数值。这是我的代码。

const MealList = (props) => {
const [count, setCount] = useState(0);
return (
<div style={{width: '70%'}}>
<h3 style={{color: 'grey', fontSize: '1.4em', fontWeight: '700', marginBottom: '1em'}}><FontAwesomeIcon
icon={faPlusCircle} style={{color: '#007bff', marginRight: '0.5em'}}/> ADD MEAL</h3>
<Table striped bordered hover>
<thead>
<tr>
<th>#</th>
<th>Meal</th>
<th>Calories</th>
<th>Time</th>
<th>Date</th>
<th>Update</th>
<th>Delete</th>
</tr>
</thead>
<tbody>
{props.meals.map(meal => (<Meal count={setCount(count + 1)} meal={meal}/>))}
</tbody>
</Table>
</div>
)
};
export default MealList;

这破坏了代码，如何正确setState？

Answer 1

如果你使用 count props 作为索引，那么你不需要 use state，你可以为此目的传递数组索引：

{props.meals.map((meal, index) => (<Meal count={index +1} meal={meal}/>))}

Answer 2

onChange={ ((=> setCount(count+1( } count={count}

您需要添加更改或类似事件来更新计数。这是示例代码