颜色主题

了解如何在你的应用中支持浅色和夜间模式。

应用支持浅色和深色配色方案很常见。以下是 Expo 项目中支持两种模式的示例：

¥It's common for apps to support light and dark color schemes. Here is an example of how supporting both modes looks in an Expo project:

配置

¥Configuration

对于 Android 和 iOS 项目，需要进行其他配置才能支持在明夜间模式之间切换。对于 Web，无需额外配置。

要配置支持的外观样式，你可以在项目的 应用配置 中使用 userInterfaceStyle 属性。默认情况下，当你使用 默认模板 创建新项目时，此属性默认设置为 automatic。

¥To configure supported appearance styles, you can use the userInterfaceStyle property in your project's app config. By default, this property is set to automatic when you create a new project with the default template.

这是一个配置示例：

¥Here is an example configuration:

{
  "expo": {
    "userInterfaceStyle": "automatic"
  }
}

你还可以通过将 android.userInterfaceStyle 或 ios.userInterfaceStyle 设置为首选值来为特定平台配置 userInterfaceStyle 属性。

¥You can also configure userInterfaceStyle property for a specific platforms by setting either android.userInterfaceStyle or ios.userInterfaceStyle to the preferred value.

如果此属性不存在，应用将默认为 light 样式。

创建开发版本时，你必须安装 expo-system-ui 以支持 Android 的外观样式。否则，userInterfaceStyle 属性将被忽略。

¥When you are creating a development build, you have to install expo-system-ui to support the appearance styles for Android. Otherwise, the userInterfaceStyle property is ignored.

如果项目配置错误且未安装 expo-system-ui，则终端中将显示以下警告：

¥If the project is misconfigured and doesn't have expo-system-ui installed, the following warning will be shown in the terminal:

还可以使用以下命令检查项目是否配置错误：

¥You can also use the following command to check if the project is misconfigured:

<activity android:configChanges="keyboard|keyboardHidden|orientation|screenSize|uiMode">

import android.content.Intent;
import android.content.res.Configuration;
public class MainActivity extends ReactActivity {
  %%placeholder-start%%... %%placeholder-end%%

  @Override
  public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    Intent intent = new Intent("onConfigurationChanged");
    intent.putExtra("newConfig", newConfig);
    sendBroadcast(intent);
  }
  %%placeholder-start%%... %%placeholder-end%%
}

Supported appearance styles

The userInterfaceStyle property supports the following values:

• automatic: Follow system appearance settings and notify about any change the user makes.
• light: Restrict the app to support light theme only.
• dark: Restrict the app to support dark theme only.

Detect the color scheme

To detect the color scheme in your project, use Appearance or useColorScheme from react-native:

import { Appearance, useColorScheme } from 'react-native';

Then, you can use useColorScheme() hook as shown below:

function MyComponent() {
  let colorScheme = useColorScheme();

  if (colorScheme === 'dark') {
    // render some dark thing
  } else {
    // render some light thing
  }
}

In some cases, you will find it helpful to get the current color scheme imperatively with Appearance.getColorScheme() or listen to changes with Appearance.addChangeListener().

Additional information

Minimal example

import { Text, StyleSheet, View, useColorScheme } from 'react-native';
import { StatusBar } from 'expo-status-bar';

export default function App() {
  const colorScheme = useColorScheme();

  const themeTextStyle = colorScheme === 'light' ? styles.lightThemeText : styles.darkThemeText;
  const themeContainerStyle =
    colorScheme === 'light' ? styles.lightContainer : styles.darkContainer;

  return (
    <View style={[styles.container, themeContainerStyle]}>
      <Text style={[styles.text, themeTextStyle]}>Color scheme: {colorScheme}</Text>
      <StatusBar />
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
  },
  text: {
    fontSize: 20,
  },
  lightContainer: {
    backgroundColor: '#d0d0c0',
  },
  darkContainer: {
    backgroundColor: '#242c40',
  },
  lightThemeText: {
    color: '#242c40',
  },
  darkThemeText: {
    color: '#d0d0c0',
  },
});

Tips

While you are developing your project, you can change your simulator's or device's appearance by using the following shortcuts:

• If using an Android Emulator, you can run adb shell "cmd uimode night yes" to enable dark mode, and adb shell "cmd uimode night no" to disable dark mode.
• If using a physical Android device or an Android Emulator, you can toggle the system dark mode setting in the device's settings.
• If working with an iOS emulator locally, you can use the Cmd ⌘ + Shift + a

用于在亮夜间模式之间切换的快捷方式。

¥shortcut to toggle between light and dark modes.