Reactjs 如何修复此错误?未定义的对象不是对象(正在评估';导航';)?
我对react native很陌生,在一个项目上工作我已经完成了项目的所有屏幕,但是当我想导航到另一个屏幕时,我在单击按钮而不是切换屏幕时遇到了这个错误。 这是我的app.js代码Reactjs 如何修复此错误?未定义的对象不是对象(正在评估';导航';)?,reactjs,react-native,expo,react-navigation,Reactjs,React Native,Expo,React Navigation,我对react native很陌生,在一个项目上工作我已经完成了项目的所有屏幕,但是当我想导航到另一个屏幕时,我在单击按钮而不是切换屏幕时遇到了这个错误。 这是我的app.js代码 import { StatusBar } from "expo-status-bar"; import React from "react"; import Cardlist from "./components/MainMenu"; export def
import { StatusBar } from "expo-status-bar";
import React from "react";
import Cardlist from "./components/MainMenu";
export default function App() {
return <Cardlist />;
}
const styles = StyleSheet.create({
container: {
flex: 1,
// backgroundColor: 'red',
alignItems: "center",
justifyContent: "center",
width: "100%",
},
});
从“世博会状态栏”导入{StatusBar};
从“React”导入React;
从“/components/MainMenu”导入卡片列表;
导出默认函数App(){
返回;
}
const styles=StyleSheet.create({
容器:{
弹性:1,
//背景颜色:“红色”,
对齐项目:“中心”,
辩护内容:“中心”,
宽度:“100%”,
},
});
这是我的按钮屏幕,我在屏幕底部创建了两个按钮,当我按下按钮时,我得到了错误
import React from "react";
import { View, Text, FlatList, Dimensions, Image } from "react-native";
import { Button } from "react-native-elements";
import { NavigationContainer } from "@react-navigation/native";
import { createStackNavigator } from "@react-navigation/stack";
import CardView from "../CardView";
import LoginScreen from "../Login/login";
import ApplyLoan from "../MainPage/ApplyLoan";
import styles from "./styles";
import imgs from "./imgs";
function BtnScreen({ navigation }) {
return (
<View style={styles.btncontainer}>
<Button
buttonStyle={styles.loginButton}
title="Login"
onPress={() => navigation.Navigate("Login")}
/>
<Button
buttonStyle={styles.loginButton}
title="Apply Now"
onPress={() => navigation.Navigate("Applynow")}
></Button>
</View>
);
}
const AuthStack = createStackNavigator();
const Cardlist = (props) => {
return (
<View style={styles.button}>
<View style={styles.container}>
<Image
style={styles.logo}
source={require("../../assets/images/123.jpeg")}
/>
</View>
<FlatList
style={styles.flat}
data={imgs}
renderItem={({ item }) => <CardView card={item} />}
showsVerticalScrollIndicator={false}
snapToAlignment={"start"}
decelerationRate={"fast"}
snapToInterval={Dimensions.get("window").height}
/>
<BtnScreen />
<NavigationContainer>
<AuthStack.Navigator>
<AuthStack.Screen name="Login" component={LoginScreen} />
<AuthStack.Screen name="Applynow" component={ApplyLoan} />
</AuthStack.Navigator>
</NavigationContainer>
</View>
);
};
export default Cardlist;
从“React”导入React;
从“react native”导入{视图、文本、平面列表、维度、图像};
从“react native elements”导入{Button};
从“@react-navigation/native”导入{NavigationContainer}”;
从“@react navigation/stack”导入{createStackNavigator};
从“./CardView”导入CardView;
从“./Login/Login”导入登录筛选;
从“./MainPage/ApplyLoan”导入ApplyLoan;
从“/styles”导入样式;
从“/imgs”导入imgs;
函数BtnScreen({navigation}){
返回(
导航。导航(“登录”)}
/>
navigation.Navigate(“Applynow”)}
>
);
}
const AuthStack=createStackNavigator();
const Cardlist=(道具)=>{
返回(
}
showsVerticalScrollIndicator={false}
snapToAlignment={“开始”}
减速率={“快”}
snapToInterval={Dimensions.get(“窗口”).height}
/>
);
};
导出默认卡片列表;
而不是
navigation.Navigate('Login')
修改导航器,使BtnScreen位于AuthStack内
<AuthStack.Navigator initialRouteName="ButtonScreen">
<AuthStack.Screen name="Login" component={LoginScreen} />
<AuthStack.Screen name="Applynow" component={ApplyLoan} />
<AuthStack.Screen name="ButtonScreen" component={BtnScreen} />
<AuthStack.Screen name="CardList" component={CardList} />
</AuthStack.Navigator>
已尝试,但仍然出现相同的错误这是因为您的BtnScreen不在AuthStack.Navigator内。只能在LoginScreen和ApplyLoan组件中使用navigation.navigate。请参阅更新的答案以向您展示示例。您可以根据自己的需要重新排列屏幕
<AuthStack.Navigator initialRouteName="ButtonScreen">
<AuthStack.Screen name="Login" component={LoginScreen} />
<AuthStack.Screen name="Applynow" component={ApplyLoan} />
<AuthStack.Screen name="ButtonScreen" component={BtnScreen} />
<AuthStack.Screen name="CardList" component={CardList} />
</AuthStack.Navigator>