Undefined 不是对象(评估 this.props.navigator.push')
Undefined is not an object( evaluating this.props.navigator.push')
我正在学习 react-native
为 android 应用程序编程。我试图在按下 TouchableOpacity
时启动第二个屏幕。我同样使用 navigator
。
我遇到了这个错误 undefined is not an object( evaluating this.props.navigator.push')
我已经检查了很多线程 但对我没有用。我不确定我在这里做错了什么,任何人都可以帮助我。提前致谢。
index.android.js
/**
* https://github.com/facebook/react-native
* @flow
*/
import React, { Component } from 'react';
import { AppRegistry, Text, View, TextInput, TouchableOpacity, ToolbarAndroid, StyleSheet,Container,ScrollView, Navigator } from 'react-native';
class App extends Component {
renderScene (route, navigator) {
return <route.component navigator={navigator} />
}
render() {
return (
<Navigator
style={styles.container}
renderScene={this.renderScene.bind(this)}
initialRoute={{component: LoginComponent}}
/>
);
}
}
class LoginComponent extends Component {
_navigate () {
this.props.navigator.push({
component: DashboardComponent
})
}
render() {
return (
<View style={{flex: 1, flexDirection: 'column'}}>
<ToolbarAndroid title='LOGIN' titleColor='white'
onIconClicked={() => this.props.navigator.pop()}
style={styles.toolbar}/>
<View style={{padding:10}}>
<TextInput style={{height: 40, borderColor:'gray', borderWidth: .5}}
placeholder="Email address" underlineColorAndroid='transparent'/>
<TextInput style={{height: 40, borderColor:'gray', borderWidth: .5}}
placeholder="Password" secureTextEntry={true} underlineColorAndroid='transparent'/>
<TouchableOpacity style={{ height: 40, marginTop: 10 , backgroundColor: '#2E8B57'}} onPress={this._navigate.bind(this)}>
<Text style={{color: 'white', textAlign: 'center', marginTop: 10, fontWeight: 'bold'}}>LOGIN</Text>
</TouchableOpacity>
</View>
</View>
);
}
}
const styles = StyleSheet.create({
toolbar: {
backgroundColor: '#2E8B57',
height: 40,
fontFamily: 'noto_serif_regular',
},
});
AppRegistry.registerComponent('ExampleOne', () => LoginComponent);
second.android.js
import React, { Component } from 'react';
class DashboardComponent extends Component {
render() {
return (
<Text>Hello!</Text>
);
}
}
您在 AppRegistry.registerComponent
中注册了错误的组件,应该是 App
而不是 LoginComponent
Navigator 组件需要先渲染,然后渲染并将 navigator 属性传递给它的场景。
我正在学习 react-native
为 android 应用程序编程。我试图在按下 TouchableOpacity
时启动第二个屏幕。我同样使用 navigator
。
我遇到了这个错误 undefined is not an object( evaluating this.props.navigator.push')
我已经检查了很多线程
index.android.js
/**
* https://github.com/facebook/react-native
* @flow
*/
import React, { Component } from 'react';
import { AppRegistry, Text, View, TextInput, TouchableOpacity, ToolbarAndroid, StyleSheet,Container,ScrollView, Navigator } from 'react-native';
class App extends Component {
renderScene (route, navigator) {
return <route.component navigator={navigator} />
}
render() {
return (
<Navigator
style={styles.container}
renderScene={this.renderScene.bind(this)}
initialRoute={{component: LoginComponent}}
/>
);
}
}
class LoginComponent extends Component {
_navigate () {
this.props.navigator.push({
component: DashboardComponent
})
}
render() {
return (
<View style={{flex: 1, flexDirection: 'column'}}>
<ToolbarAndroid title='LOGIN' titleColor='white'
onIconClicked={() => this.props.navigator.pop()}
style={styles.toolbar}/>
<View style={{padding:10}}>
<TextInput style={{height: 40, borderColor:'gray', borderWidth: .5}}
placeholder="Email address" underlineColorAndroid='transparent'/>
<TextInput style={{height: 40, borderColor:'gray', borderWidth: .5}}
placeholder="Password" secureTextEntry={true} underlineColorAndroid='transparent'/>
<TouchableOpacity style={{ height: 40, marginTop: 10 , backgroundColor: '#2E8B57'}} onPress={this._navigate.bind(this)}>
<Text style={{color: 'white', textAlign: 'center', marginTop: 10, fontWeight: 'bold'}}>LOGIN</Text>
</TouchableOpacity>
</View>
</View>
);
}
}
const styles = StyleSheet.create({
toolbar: {
backgroundColor: '#2E8B57',
height: 40,
fontFamily: 'noto_serif_regular',
},
});
AppRegistry.registerComponent('ExampleOne', () => LoginComponent);
second.android.js
import React, { Component } from 'react';
class DashboardComponent extends Component {
render() {
return (
<Text>Hello!</Text>
);
}
}
您在 AppRegistry.registerComponent
中注册了错误的组件,应该是 App
而不是 LoginComponent
Navigator 组件需要先渲染,然后渲染并将 navigator 属性传递给它的场景。