官方文档

官方文档链接

https://reactnative.cn/docs/using-a-listview

具体内容

FlatList & SectionList

1. React Native 提供了几个适用于展示长列表数据的组件，一般而言我们会选用FlatList或是SectionList。

2. FlatList组件用于显示一个垂直的滚动列表，其中的元素之间结构近似而仅数据不同。

   1. FlatList更适于长列表数据，且元素个数可以增删。和ScrollView不同的是，FlatList并不立即渲染所有元素，而是优先渲染屏幕上可见的元素。
   2. FlatList组件必须的两个属性是data和renderItem。data是列表的数据源，而renderItem则从数据源中逐个解析数据，然后返回一个设定好格式的组件来渲染。
   3. 下面的例子创建了一个简单的FlatList，并预设了一些模拟数据。首先是初始化FlatList所需的data，其中的每一项（行）数据之后都在renderItem中被渲染成了Text组件，最后构成整个FlatList。

3. 如果要渲染的是一组需要分组的数据，也许还带有分组标签的，那么SectionList将是个不错的选择。

具体操作

1）移动文件

1. 将(tabs)中的index.jsx contact.jsx移动到app文件夹下面；
2. 删除（tabs）和（coffee）文件夹。

2）修改_layout.tsx文件

alt+z 可开启自动换行

1. 删除导入语句

   import { DarkTheme, DefaultTheme, ThemeProvider } from '@react-navigation/native';

   import 'react-native-reanimated';

   import { StatusBar } from 'expo-status-bar';(如果有的话)

2. 添加导入语句

   import { Appearance } from 'react-native';

   import { Colors } from '@/constants/Colors';

3. 修改并添加具体的代码语句

   const colorScheme = Appearance.getColorScheme(); // 调用Appearance 来提供配色方案 'light' | 'dark'
   const theme = colorScheme === 'dark' ? Colors.dark : Colors.light; // 根据当前的配色方案选择对应的主题颜色
   

4. 对报错语句进行修改

   // 直接删除掉相应的语句就行，下面是删除之后的代码：
   return (<Stack><Stack.Screen name="(tabs)" options={{ headerShown: false }} />{/* <Stack.Screen name="(coffee)" options={{ headerShown: false }} /> */}{/* 为每一个文件添加一个堆栈 */}{/*   <Stack.Screen name="index" options={{title: "Home", headerShown:false}} /><Stack.Screen name="contact" options={{title: "Contact Us"}} /> */}<Stack.Screen name="+not-found" /></Stack>     );
   

   之后，对Stack添加选项，设置标题headerStyle背景颜色 backgroundColor的时候需要对Colors文件添加代码hearderBackground。

return (<Stack screenOptions={{headerStyle: {backgroundColor: theme.headerBackground},headerTintColor: theme.text, headerShadowVisible: false,}}><Stack.Screen name="index" options={{ headerShown: false, title: 'Home'}} /><Stack.Screen name="menu" options={{ headerShown: true, title: 'Meanu', headerTitle: 'Coffee Shop  Menu' }} /><Stack.Screen name="contact" options={{ headerShown: true, title: 'Contact', headerTitle: 'Contact Us' }} /><Stack.Screen name="+not-found" options={{headerShown: false}}/></Stack> );

需要注意的是，还没有创建menu相关的文件，可能会报错。

5. 最终的_layout.tsx文件的代码

   import { useFonts } from 'expo-font';
   import { Stack } from 'expo-router';
   import * as SplashScreen from 'expo-splash-screen';
   import { useEffect } from 'react';
   import { Appearance } from 'react-native';
   import { Colors } from '@/constants/Colors';// Prevent the splash screen from auto-hiding before asset loading is complete.
   SplashScreen.preventAutoHideAsync();export default function RootLayout() {const colorScheme = Appearance.getColorScheme(); // 调用Appearance 来提供配色方案 'light' | 'dark'const theme = colorScheme === 'dark' ? Colors.dark : Colors.light; // 根据当前的配色方案选择对应的主题颜色const [loaded] = useFonts({SpaceMono: require('../assets/fonts/SpaceMono-Regular.ttf'),});useEffect(() => {if (loaded) {SplashScreen.hideAsync();}}, [loaded]);if (!loaded) {return null;}return (<Stack screenOptions={{headerStyle: {backgroundColor: theme.headerBackground},headerTintColor: theme.text, headerShadowVisible: false,}}><Stack.Screen name="index" options={{ headerShown: false, title: 'Home'}} /><Stack.Screen name="menu" options={{ headerShown: true, title: 'Meanu', headerTitle: 'Coffee Shop  Menu' }} /><Stack.Screen name="contact" options={{ headerShown: true, title: 'Contact', headerTitle: 'Contact Us' }} /><Stack.Screen name="+not-found" options={{headerShown: false}}/></Stack> );
   }
   

3）添加并编写menu.jsx文件

在app文件夹下面添加menu.jsx文件（注意，此时的menu.jsx是和index.jsx文件是同等级的）

提到SafeAreaViewhttps://reactnative.cn/docs/safeareaview

import { StyleSheet, Appearance, Platform, SafeAreaView, ScrollView, FlatList, View, Text, Image } from "react-native";
import { Colors } from "@/constants/Colors";export default function MenuScreen(){const colorScheme = Appearance.getColorScheme();const theme = colorScheme === "dark"? Colors.dark : Colors.light;const styles = createStyles(theme, colorScheme);// SafeAreaView在移动设备上使用，ScrollView在web上使用const Container = Platform.OS === 'web' ? ScrollView : SafeAreaView;// 菜单屏幕功能的返回return (// 这里的Container是父容器<Container>  {/* data需要具体的数值，所以在constants文件夹下面创建文件MenuItems.js */}<FlatListdata ={[]}renderItem={({item}) => ()}></FlatList></Container>)
}function createStyles(theme, colorScheme) {return StyleSheet.create({});
}

上述内容存在不完善，提示一个错误。后面会完善

4）编写MenuItems.js

在constants文件夹下面创建文件MenuItems.js 。

export const MENU_ITEMS = [{"id":1,"title":"Espresso","description": "Strong, concentrated coffee.",},{"id":2,"title":"Latte","description": "Rich, smooth milk with a smooth texture.",},{"id":3,"title":"Cappuccino","description": "A smooth, rich, and creamy coffee with a smooth texture.",},{"id":4,"title":"Americano","description": "A strong, thick coffee with a smooth texture.",},{"id":5,"title":"Mocha","description": "A smooth, rich, and creamy coffee with a smooth texture.",},{"id":6,"title":"Macchiato","description": "A smooth, rich, and creamy coffee with a smooth texture.",},{"id":7,"title":"affogato","description": "A smooth, rich, and creamy coffee with a smooth texture.",},{"id":8,"title":"coldblew","description": "Rich, smooth milk with a smooth texture.",},{"id":9,"title":"cortado","description": "A strong, thick coffee with a smooth texture.",},{"id":10,"title":"flatwhite","description": "A smooth, rich, and creamy coffee with a smooth texture.",}
]
// 上述内容不一定准确，只是一个示例

5）创建menu图像文件夹

在images目录下面，创建menu文件夹，并将已有的coffee图像移动到该文件夹当中。

图像来源: https://github.com/gitdagray/react-native-course/tree/lesson-4/MyApp/assets/images/menu

6）创建调用图像的文件MenuImages.js

在constants文件夹下面创建文件MenuImages.js

创建数组存储这些咖啡。

import espresso from "@/assets/images/menu/espresso.png"
import americano from "@/assets/images/menu/americano.png"
import latte from "@/assets/images/menu/latte.png"
import cappuccino from "@/assets/images/menu/cappuccino.png"
import macchiato from "@/assets/images/menu/macchiato.png"
import mocha from "@/assets/images/menu/mocha.png"
import flatwhite from "@/assets/images/menu/flatwhite.png"
import cortado from "@/assets/images/menu/cortado.png"
import coldbrew from "@/assets/images/menu/coldbrew.png"
import affogato from "@/assets/images/menu/affogato.png"export default [espresso,americano,latte,cappuccino,macchiato,mocha,flatwhite,cortado,coldbrew,affogato
]

欢迎交流~
一切顺利！