TypeError: Cannot read property ‘navigate‘ of undefined React Native
TypeError: 无法读取未定义的属性 'navigate'(React Native)
题意:TypeError: 无法读取未定义的属性 'navigate'(React Native)
问题背景:
Here's a Stack Navigator inside a MainStack.js:
这是 `MainStack.js` 中的一个 Stack Navigator:
import React from 'react'
import { createStackNavigator } from '@react-navigation/stack';
import Main from './Main'
import ScannerMarker from './ScannerMarker';
const Stack = createStackNavigator();
export default function MainStack() {
return(
<Stack.Navigator initialRouteName='Main' screenOptions={{headerShown: false}}>
<Stack.Screen name='Main' component={Main} />
<Stack.Screen name='ScannerMarker' component={ScannerMarker} />
</Stack.Navigator>
);
}
And ScannerMarker.js:
import React from 'react';
import { StyleSheet, View, Text, Dimensions, Pressable } from 'react-native';
import MaterialIcon from 'react-native-vector-icons/MaterialIcons';
import Feather from 'react-native-vector-icons/Feather';
import Octicon from 'react-native-vector-icons/Octicons'
import Main from './Main';
export default function ScannerMarker({ navigation, setModalVisible }) {
return (
<View style={styles.markerContainer}>
<View style={styles.topContainer}>
<View style={styles.topBar}>
<MaterialIcon name="support-agent" size={32} color="#fffeef" backgroundColor={'none'} onPress={() => navigation.navigate(Main)} />
<Feather name="x" size={32} color="#fffeef" backgroundColor={'none'} onPress={() => navigation.goBack(Support)}/>
</View>
<Text style={styles.topText}>Point scanner to{'\n'}vending qr-code</Text>
</View>
<View style={styles.middleContainer}>
<View style={styles.leftContainer}></View>
<View style={styles.scannerSquare}></View>
<View style={styles.rightContainer}></View>
</View>
<View style={styles.bottomContainer}>
<Pressable style={styles.button} onPress={() => setModalVisible(false)}>
<Octicon name="number" size={20} color="#fffeef" style={styles.chargerIcon}/>
<Text style={styles.buttonText}> Enter vending{'\n'}number</Text>
</Pressable>
</View>
</View>
)
}
ScannerMarker is a part of a Scanner in Scanner.js:
`ScannerMarker` 是 `Scanner.js` 中 `Scanner` 的一部分:
import React from 'react';
import { StyleSheet, Linking, Dimensions} from 'react-native';
import QRCodeScanner from 'react-native-qrcode-scanner';
import { RNCamera } from 'react-native-camera';
import ScannerMarker from './ScannerMarker';
export default function Scanner({ modalVisible, setModalVisible }) {
onSuccess = e => {
Linking.openURL(e.data)
setModalVisible(!modalVisible)
};
return (
<QRCodeScanner
onRead={this.onSuccess}
flashMode={RNCamera.Constants.FlashMode.auto}
cameraStyle={styles.cameraStyle}
showMarker={true}
customMarker={
<ScannerMarker setModalVisible={setModalVisible}> </ScannerMarker>
}
/>
);
}
MainStack is rendered inside a Drawer Navigator in Drawer.js:
`MainStack` 在 `Drawer.js` 中的 Drawer Navigator 内渲染:
import React from 'react';
import { StyleSheet, View, Linking} from 'react-native';
import { createDrawerNavigator, DrawerItemList, DrawerContentScrollView, DrawerItem} from '@react-navigation/drawer';
import MaterialCommunityIcon from 'react-native-vector-icons/MaterialCommunityIcons';
const Drawer = createDrawerNavigator();
export default function MyDrawer(props) {
return (
<Drawer.Navigator
...
>
<Drawer.Screen
name='MainStack'
component={MainStack}
options={{
title: 'Charge Away',
drawerIcon: () => (<MaterialCommunityIcon name="lightning-bolt" size={45} color="#2E2A00" style={{marginEnd: -30, marginStart: -10}} />)
}}
/>
...
<Drawer.Navigator>
);
}
When i press on icons with "onPress={() => navigation.navigate(...)}" or onPress={() => navigation.goBack()} I get the following errors:
当我按下带有 `onPress={() => navigation.navigate(...)}` 或 `onPress={() => navigation.goBack()}` 的图标时,我收到以下错误:
TypeError: Cannot read property 'navigate' of undefined and TypeError: Cannot read property 'goBack' of undefined
So I don't know what's the problem. navigation parameter is declared and all of the components are in the Stack Navigator.
所以我不知道问题出在哪里。`navigation` 参数已经声明,并且所有组件都在 Stack Navigator 中。
Everything is wrapped in NavigationContainer in App.js:
所有内容都在 `App.js` 中的 `NavigationContainer` 中包装:
import * as React from 'react';
import { NavigationContainer} from '@react-navigation/native';
import MyDrawer from './components/Drawer'
export default function App() {
return (
<NavigationContainer>
<MyDrawer />
</NavigationContainer>
);
}
问题解决:
I've solved the problem with useNavigation hook:
我通过使用 `useNavigation` 钩子解决了这个问题:
import { View, Button } from 'react-native';
import { useNavigation } from '@react-navigation/native';
export default function MyComp() {
const navigation = useNavigation();
return (
<View>
<Button
title="Go to Home"
onPress={() => navigation.navigate('Home')}
/>
</View>
);
};
Another option is to pass navigation to MyComp with props:
另一个选项是通过 props 将 `navigation` 传递给 `MyComp`:
export default function MyComp( {navigation} ) {
//...
};
<MyComp navigation={props.navigation} />
Source: Access the navigation prop from any component | React Navigation

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