Create React App 腳手架工具要门，是創(chuàng)建React項目的最佳方式拟淮。
創(chuàng)建項目前要滿足 Node >= 8.10 和 npm >= 5.6捕透。
如何安裝和使用React腳手架
npm install -g create-react-app
cd Desktop
npx create-react-app my-app
cd my-app
npm start
npm install -g create-react-app 安裝腳手架
重啟項目時運行npm run start也可以是npm start
項目名稱菇爪，必須為小寫字母my-app
報錯信息如下：
$ react-scripts start
There might be a problem with the project dependency tree.
It is likely not a bug in Create React App, but something you need to fix locally.
The react-scripts package provided by Create React App requires a dependency:
“webpack”: “4.19.1”
Don’t try to install it manually: your package manager does it automatically.
However, a different version of webpack was detected higher up in the tree:
/Users/apple/node_modules/webpack (version: 4.28.2)
Manually installing incompatible versions is known to cause hard-to-debug issues.
If you would prefer to ignore this check, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That will permanently disable this message but you might encounter other issues.
To fix the dependency tree, try following the steps below in the exact order:
- Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.
- Delete node_modules in your project folder.
- Remove “webpack” from dependencies and/or devDependencies in the package.json file in your project folder.
- Run npm install or yarn, depending on the package manager you use.
In most cases, this should be enough to fix the problem.
If this has not helped, there are a few other things you can try:
If you used npm, install yarn (http://yarnpkg.com/) and repeat the above steps with it instead.
This may help because npm has known issues with package hoisting which may get resolved in future versions.Check if /Users/apple/node_modules/webpack is outside your project directory.
For example, you might have accidentally installed something in your home folder.Try running npm ls webpack in your project folder.
This will tell you which other package (apart from the expected react-scripts) installed webpack.
If nothing else helps, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That would permanently disable this preflight check in case you want to proceed anyway.
P.S. We know this message is long but please read the steps above ?? We hope you find them helpful!
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
解決問題思路：
創(chuàng)建一個 .env 文件 SKIP_PREFLIGHT_CHECK=true 添加這句代碼唠梨，在終端輸入npm start重啟就好了袋励。
下圖參考圖：
