通用组件，允许将初始 React 组件设置为在应用的根 React Native 视图中本地渲染。
将初始 React 组件设置为在 iOS、Android 和 Web 上应用的根 React Native 视图中本地渲染。它还添加了用于 npx expo start 的开发专用调试工具。
¥Sets the initial React component to render natively in the app's root React Native view on iOS, Android, and the web. It also adds dev-only debugging tools for use with npx expo start.
¥Installation
- npx expo install expo¥Manual Android setup
仅当你的应用不使用 Expo 预建 持续生成 android 目录时才需要这样做。
¥This is only required if your app does not use Expo Prebuild to continuously generate the android directory.
更新 android/app/src/main/your-package/MainActivity.java 文件以在 getMainComponentName 函数中使用名称 main。
¥Update the android/app/src/main/your-package/MainActivity.java file to use the name main in the getMainComponentName function.
@Override
protected String getMainComponentName() {
+ return "main";
}
¥Manual iOS setup
仅当你的应用不使用 Expo 预建 持续生成 ios 目录时才需要这样做。
¥This is only required if your app does not use Expo Prebuild to continuously generate the ios directory.
更新 iOS ios/your-name/AppDelegate.(m|mm|swift) 文件以使用 application:didFinishLaunchingWithOptions: 函数的 createRootViewWithBridge:bridge moduleName:@"main" initialProperties:initProps 行中的 moduleName main。
¥Update the iOS ios/your-name/AppDelegate.(m|mm|swift) file to use the moduleName main in the createRootViewWithBridge:bridge moduleName:@"main" initialProperties:initProps line of the application:didFinishLaunchingWithOptions: function.
import { registerRootComponent } from 'expo';
registerRootComponent(component)设置初始 React 组件以在应用的根 React Native 视图 (RCTView) 中本地渲染。
¥Sets the initial React component to render natively in your app's root React Native view (RCTView).
该函数执行以下操作：
¥This function does the following:
调用 React Native 的 AppRegistry.registerComponent
¥Invokes React Native's AppRegistry.registerComponent
在 web 上调用 React Native web 的 AppRegistry.runApplication 以渲染到根 index.html 文件。
¥Invokes React Native web's AppRegistry.runApplication on web to render to the root index.html file.
在全局范围内填充 process.nextTick 函数。
¥Polyfills the process.nextTick function globally.
添加了对将 fontFamily React Native 风格与 expo-font 包一起使用的支持。
¥Adds support for using the fontFamily React Native style with the expo-font package.
此功能还添加了以下仅在生产包中删除的开发功能。
¥This function also adds the following dev-only features that are removed in production bundles.
向应用添加快速刷新和打包拆分指示器。
¥Adds the Fast Refresh and bundle splitting indicator to the app.
断言 expo-updates 包是否配置错误。
¥Asserts if the expo-updates package is misconfigured.
在浏览器中运行时，断言 react-native 是否不是 react-native-web 的别名。
¥Asserts if react-native is not aliased to react-native-web when running in the browser.
Polyfills console.log 通过 /logs 将日志发送到开发服务器
¥Polyfills console.log to send logs to the dev server via /logs
¥Arguments
组件 (ReactComponent) -- 渲染应用其余部分的 React 组件类。
¥component (ReactComponent) -- The React component class that renders the rest of your app.
¥Returns
无返回值。
¥No return value.
¥Common questions
¥What if I want to name my main app file something other than App.js?
你可以将 package.json 中的 "main" 设置为项目中的任何文件。如果你这样做，那么你需要使用 registerRootComponent；如果你使用自定义条目文件，export default 不会使该组件成为应用的根。
¥You can set the "main" in package.json to any file within your
project. If you do this, then you need to use registerRootComponent;
export default will not make this component the root for the app
if you are using a custom entry file.
例如，假设你希望将 "src/main.js" 作为应用的入口文件 - 也许你不喜欢在项目根目录中包含 JavaScript 文件。首先，在 package.json 中设置：
¥For example, let's say you want to make "src/main.js" the entry file
for your app -- maybe you don't like having JavaScript files in the
project root. First, set this in package.json:
{
"main": "src/main.js"
}
然后在 "src/main.js" 中，确保调用 registerRootComponent 并传入要在应用根目录渲染的组件。
¥Then in "src/main.js", make sure you call registerRootComponent and
pass in the component you want to render at the root of the app.
import { registerRootComponent } from 'expo';
import { View } from 'react-native';
function App() {
return <View />;
}
registerRootComponent(App);