reactjs - 使用 useMemo 或 useCallback VS useRef 的空依赖关系

Question

在此GitHub issue我基本上建议改变:

x = useCallback( ... , []);

致:

x = useRef( ... ).current;

两者是相同的，但使用 useRef React 不会比较依赖关系。

对此的答复附带了一个问题:

Is there ever a situation where a dependency-less useMemo or useCallback would be a better choice than useRef?

我想不出一个，但我可能忽略了一些用例。

那么有人能想到这样的情况吗？

Answer 1

根据 React Hooks API 文档:

Keep in mind that useRef doesn’t notify you when its content changes. Mutating the .current property doesn’t cause a re-render ... Using a callback ref ensures that even if a child component displays the measured node later (e.g. in response to a click), we still get notified about it in the parent component and can update the measurements.

您可以阅读更多相关信息here和here .