我是一个原生 react 新手。我正在开发一个示例应用程序，用户在打开应用程序时将看到启动屏幕，稍后他将看到登录屏幕。但我无法弄清楚从启动屏幕导航到登录屏幕的方法。
下面是代码 fragment ，
启动画面的 app.js 文件 -
import React, { Component } from 'react';
import { Platform, StyleSheet, View, Text, Image, TouchableOpacity, Alert } from 'react-native';
export default class Myapp extends Component<{}>
{
constructor(){
super();
this.state={
isVisible : true,
}
}
Hide_Splash_Screen=()=>{
this.setState({
isVisible : false
});
}
componentDidMount(){
var that = this;
setTimeout(function(){
that.Hide_Splash_Screen();
}, 5000);
}
render()
{
let Splash_Screen = (
<View style={styles.SplashScreen_RootView}>
<View style={styles.SplashScreen_ChildView}>
{/* Put all your components Image and Text here inside Child view which you want to show in Splash Screen. */}
<Image source={{uri: 'https://reactnativecode.com/wp-content/uploads/2018/01/welcome.png'}}
style={{width:'100%', height: '100%', resizeMode: 'contain'}} />
</View>
<TouchableOpacity
activeOpacity = { 0.5 }
style={styles.TouchableOpacity_Style}
onPress={this.Hide_Splash_Screen} >
<Image source={{uri: 'https://reactnativecode.com/wp-content/uploads/2018/01/close_button.png'}}
style={{width:25, height: 25}} />
</TouchableOpacity>
</View> )
return(
<View style = { styles.MainContainer }>
<Text style={{textAlign: 'center'}}> Hello Guys </Text>
{
(this.state.isVisible === true) ? Splash_Screen : null
}
</View>
);
}
}
const styles = StyleSheet.create(
{
MainContainer:
{
flex: 1,
justifyContent: 'center',
alignItems: 'center',
paddingTop: ( Platform.OS === 'ios' ) ? 20 : 0
},
SplashScreen_RootView:
{
justifyContent: 'center',
flex:1,
margin: 10,
position: 'absolute',
width: '100%',
height: '100%',
},
SplashScreen_ChildView:
{
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#00BCD4',
flex:1,
margin: 20,
},
TouchableOpacity_Style:{
width:25,
height: 25,
top:9,
right:9,
position: 'absolute'
}
});
login.js fragment -
import React, { Component } from 'react';
import { StyleSheet, TextInput, View, Alert, Button, Text} from 'react-native';
// Importing Stack Navigator library to add multiple activities.
import { StackNavigator } from 'react-navigation';
// Creating Login Activity.
class LoginActivity extends Component {
// Setting up Login Activity title.
static navigationOptions =
{
title: 'LoginActivity',
};
constructor(props) {
super(props)
this.state = {
UserEmail: '',
UserPassword: ''
}
}
UserLoginFunction = () =>{
const { UserEmail } = this.state ;
const { UserPassword } = this.state ;
fetch('https://reactnativecode.000webhostapp.com/User_Login.php', {
method: 'POST',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
},
body: JSON.stringify({
email: UserEmail,
password: UserPassword
})
}).then((response) => response.json())
.then((responseJson) => {
// If server response message same as Data Matched
if(responseJson === 'Data Matched')
{
//Then open Profile activity and send user email to profile activity.
this.props.navigation.navigate('Second', { Email: UserEmail });
}
else{
Alert.alert(responseJson);
}
}).catch((error) => {
console.error(error);
});
}
render() {
return (
<View style={styles.MainContainer}>
<Text style= {styles.TextComponentStyle}>User Login Form</Text>
<TextInput
// Adding hint in Text Input using Place holder.
placeholder="Enter User Email"
onChangeText={UserEmail => this.setState({UserEmail})}
// Making the Under line Transparent.
underlineColorAndroid='transparent'
style={styles.TextInputStyleClass}
/>
<TextInput
// Adding hint in Text Input using Place holder.
placeholder="Enter User Password"
onChangeText={UserPassword => this.setState({UserPassword})}
// Making the Under line Transparent.
underlineColorAndroid='transparent'
style={styles.TextInputStyleClass}
secureTextEntry={true}
/>
<Button title="Click Here To Login" onPress={this.UserLoginFunction} color="#2196F3" />
</View>
);
}
}
// Creating Profile activity.
class ProfileActivity extends Component
{
// Setting up profile activity title.
static navigationOptions =
{
title: 'ProfileActivity',
};
render()
{
const {goBack} = this.props.navigation;
return(
<View style = { styles.MainContainer }>
<Text style = {styles.TextComponentStyle}> { this.props.navigation.state.params.Email } </Text>
<Button title="Click here to Logout" onPress={ () => goBack(null) } />
</View>
);
}
}
export default MainProject = StackNavigator(
{
First: { screen: LoginActivity },
Second: { screen: ProfileActivity }
});
const styles = StyleSheet.create({
MainContainer :{
justifyContent: 'center',
flex:1,
margin: 10,
},
TextInputStyleClass: {
textAlign: 'center',
marginBottom: 7,
height: 40,
borderWidth: 1,
// Set border Hex Color Code Here.
borderColor: '#2196F3',
// Set border Radius.
borderRadius: 5 ,
},
TextComponentStyle: {
fontSize: 20,
color: "#000",
textAlign: 'center',
marginBottom: 15
}
});
现在如何在主文件中使用 login.js 文件夹，反之亦然？
最佳答案
我会给你一个示例应用程序的代码。它只包含三个屏幕，只是从代码中弄清楚，如何正确地从一个屏幕导航到另一个屏幕。 App.js 包含 stack-navigator。
其他屏幕都是导入的。先研究一下stack navigator。
https://drive.google.com/open?id=1VdqBtawsx_Z0c3b7CUDv_d8lfcSlDvZo (上面是示例应用程序的 Google 云端硬盘链接)
它包含三个屏幕
splashscreen、profilescreen、profiledetailscreen它是
react-native应用程序的最新版本，就像npm启动你之后一样 必须单独启动模拟器，然后单击“a”启动 模拟器内的应用程序。或从名为 Expo 的应用读取
npm start之后出现的终端内生成的条形码，以在设备中启动它。
关于android - 如何在 native react 中从启动屏幕导航到登录屏幕？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49510634/