reactjs - React useCallback 钩子(Hook)用于 map 渲染

Question

将回调传递给组件时，我应该使用 useCallback Hook 返回内存回调(以防止不需要的渲染):

import doSomething from "./doSomething";
const FrequentlyRerenders = ({ id }) => {
  const onEvent = useCallback(() => doSomething(id), [id]);
  return (
    <ExpensiveComponent onEvent={ onEvent } />
  );
};

但是如果我使用 map 怎么办？例如:

import doSomething from "./doSomething";
const FrequentlyRerendersMap = ({ ids }) => {
  return ids.map(id => {
    const onEvent = useCallback(() => doSomething(id), [id]);
    return (
      <ExpensiveComponent key={id} onEvent={ onEvent } />
    );
  });
};

我应该如何正确使用useCallback？以上是传递多个回调的正确方法吗？它真的有效并且知道根据数组的一项来内存每个回调吗？

Answer 1

将返回的映射的JSX转换成组件，然后就可以使用Callback了，没有问题

import doSomething from "./doSomething";
const MappedComponent =(props) => {
   const onEvent = useCallback(() => doSomething(props.id), []);
   return (
      <ExpensiveComponent onEvent={ onEvent } />
   );
}

const FrequentlyRerendersMap = ({ ids }) => {
  return ids.map(id => {
    return <MappedComponent key={id} id={id} />
  });
};