{"id":20814034,"url":"https://github.com/cqh963852/react-refresh-test","last_synced_at":"2026-05-01T22:32:56.544Z","repository":{"id":39349457,"uuid":"216020440","full_name":"cqh963852/react-refresh-test","owner":"cqh963852","description":"A tutorial about react function component","archived":false,"fork":false,"pushed_at":"2023-03-31T02:50:25.000Z","size":1470,"stargazers_count":2,"open_issues_count":1,"forks_count":0,"subscribers_count":1,"default_branch":"master","last_synced_at":"2025-12-27T08:24:48.318Z","etag":null,"topics":["hook","react","tutorial"],"latest_commit_sha":null,"homepage":null,"language":"TypeScript","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/cqh963852.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null,"notice":null,"maintainers":null,"copyright":null,"agents":null,"dco":null,"cla":null}},"created_at":"2019-10-18T12:36:01.000Z","updated_at":"2023-03-31T02:19:37.000Z","dependencies_parsed_at":"2023-02-02T23:02:43.213Z","dependency_job_id":null,"html_url":"https://github.com/cqh963852/react-refresh-test","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/cqh963852/react-refresh-test","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/cqh963852%2Freact-refresh-test","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/cqh963852%2Freact-refresh-test/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/cqh963852%2Freact-refresh-test/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/cqh963852%2Freact-refresh-test/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/cqh963852","download_url":"https://codeload.github.com/cqh963852/react-refresh-test/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/cqh963852%2Freact-refresh-test/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":32515838,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-04-30T13:12:12.517Z","status":"online","status_checked_at":"2026-05-01T02:00:05.856Z","response_time":64,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["hook","react","tutorial"],"created_at":"2024-11-17T21:09:27.027Z","updated_at":"2026-05-01T22:32:56.526Z","avatar_url":"https://github.com/cqh963852.png","language":"TypeScript","funding_links":[],"categories":[],"sub_categories":[],"readme":"# 此仓库是关于 react 的一些简单的总结，可以避免在代码编写时的一些坑\n\n## 一个普通的函数组件在什么时候会更新？（更新：函数重新执行）（例子 1）\n\n- 父组件更新\n- 组件 state 更新\n\n## 如何避免这种无关的更新？（父组件更新可能带来的副作用）\n\n- 分割父组件（例子 2）\n\n        将父组件中，与其子组件无关的部分分割，将分割出的组件作为自组件与其组合。\n        优势：降低单个组件复杂度。\n        劣势：代码成本较大，需要增加一个文件，并且调整当前组件的逻辑。\n\n- 使用 memo（例子 3）\n\n        memo 的演变过程： `React.PureComponent -\u003e React.Memo`\n        API解释：当组件的props不变时，组件不会更新\n        优势：在原有基础上修改更快\n        劣势：可能会因为意外导致memo失效（详见后文）。相比于上一种方法，会多更新一部分组件。\n\n## 亲戚组件之间如何共享数据。（例子 4 基于 例子 1）（手敲例子效果更好）\n\n- context（例子 5 基于 例子 3）（例子 6 基于例子 2）（手敲例子效果更好）\n\n  - 在例子 6 中，为什么数据更新以后，`AXX.tsx`也会刷新？是从父组件刷新导致的吗？还是用了`useContext`的组件导致的？\n    测试 1：去除`ABB.tsx`的 counter 引用，观察 `ABB.tsx`是否刷新\n    测试 2：给`A.tsx`添加`memo`，观察所有组件刷新情况\n\n    测试 1 之后我们可以发现：即使我们将 `ABB.tsx` 的 `Counter` 组件去除，`AAB.tsx` 依旧会刷新，根据我们之前的推论，这是由父组件更新引起的刷新。而父组件的更新是因为 `Counter`组件 调用`decrease increase` 函数之后引起了`useCounter`中`count`的变化。\n\n    但是测试 2 给了我们迎头一击，以我们上述的推论来看的话，`Counter` 应该停止更新，但是显然不是，所以我们的推论有漏洞。[原因](https://reactjs.org/docs/hooks-reference.html#usecontext)在 react 官网中已经给出。\n\n    所以我们对于 react 组件更新的情况需要再加一条，当 context 中的数据产生变化时，组件更新。\n\n    \u003e When the nearest \u003cMyContext.Provider\u003e above the component updates, this Hook will trigger a rerender with the latest context value passed to that MyContext provider\n\n- redux（下次再讲）\n\n## 复杂结构数据共享（context）（例子 7 基于 例子 6）\n\n- 例子 7\n\n  我们只保留`AAB.tsx`和`ABB.tsx`的`Counter`，但是这样的话，Context 似乎没有理由再呆在最外层。那么我们给`A.tsx`增加两个按钮。分别是 increase 和 decrease 按钮。\n\n  哦，看上去修改以后的程序出现了一点意外。为什么之前不再更新的组件也更新了呢？\n\n  让我们检查一下我们的A组件，看看他为什么更新了。\n\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fcqh963852%2Freact-refresh-test","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fcqh963852%2Freact-refresh-test","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fcqh963852%2Freact-refresh-test/lists"}