我有以下错误
未捕获的不变违规:元素类型无效:需要一个字符串(对于内置组件)或一个类/函数(对于复合组件),但得到:未定义。您可能忘记从定义的文件中导出组件
我已经阅读了很多关于这个错误的帖子,比如这个或这个 ,但他们都说同样的:我错误地导出了我的组件。但我不明白我的出口出了什么问题
import React, {Component} from 'react';
import {Platform, StyleSheet, Text, View, Image, ImageBackground, Linking, TouchableOpacity, TouchableHighlight, Alert, Button } from 'react-native';
import { createStackNavigator, createAppContainer } from "react-navigation";
import { FormLabel, FormInput, FormValidationMessage} from 'react-native-elements';
type Props = {};
export default class Login extends Component<Props> {
constructor(props) {
super(props);
state = {
login: '',
};
}
someFunction(){
Alert.alert("test")
}
onPress (){
this.props.navigation.navigate('Home')
}
checkLogin(login){
Alert.alert('test');
}
render() {
return (
<View style={styles.container}>
<Image
style={styles.image}
source={require("./images/logo.png")}>
</Image>
<FormLabel style={styles.flex1}>enter Login of your Hotel</FormLabel>
<FormInput
//value = {this.state.login}
onChangeText={login => this.checkLogin({login})}
//onChangeText={this.checkLogin.bind(login)}
placeholder='enter your login'
autoCapitalize = 'none'
/>
</View>
);
}
}
和 App.js :
import React, {Component} from 'react';
import {Platform, StyleSheet, Text, View, Image,ImageBackground, Linking, TouchableOpacity, Alert } from 'react-native';
import { createStackNavigator, createAppContainer } from "react-navigation"
import {HomeScreen} from './HomeScreen';
import Display from './Display';
import Login from './Login';
export default class App extends React.Component {
render() {
return <AppContainer />;
}
}
const AppNavigator = createStackNavigator({
Home: HomeScreen,
Display: Display,
Login: Login,
},
{
initialRouteName: "Login",
headerMode: 'none',
}
);
const AppContainer = createAppContainer(AppNavigator);
你知道什么是错的吗?只有当我使用 FormInput 和 FormLabel 时才会出现错误。如果我用你好替换它会显示