React-native:将场景绑定到 NavigationBar [英] React-native: Binding scene to NavigationBar
问题描述
我正在构建这个问答应用程序,但遇到了这个障碍:
I'm putting together this Ask/Answer App, and came across this hurdle:
我想从导航栏中触发一个场景中的函数.类似于登录应用程序,我在导航栏中有一个按钮来提交答案:
I want to trigger a function in a scene from the navigationBar. Similar to a Login app I have a button in the NavigationBar to Submit an answer:
RightButton(route, navigator, index, navState) {
if (route.name=='TextInputView'){
return <TouchableHighlight
underlayColor="transparent"
style={{ marginRight:13, marginTop:0}}
onPress={() => this.refs.TextInputView.submitSolution()}>
<Text style={ styles.leftNavButtonText }>Done</Text>
</TouchableHighlight>
}
renderscene(route,navigator) 看起来像这样:
the renderscene(route,navigator) looks like so:
if (route.name == 'TextInputView'){
return <TextInputView ref="TextInputView" navigator={navigator} {...route.passProps}/>
}
当然在TextInputView"组件中我有一个submitSolution"功能...
and of course in the "TextInputView" component I have a "submitSolution" function...
问题是如果我在现场并按下完成"——我总是得到:未定义不是一个对象(评估'_this2.refs.TextInputView')
problem is if I'm in the scene and press the "Done" - I always get: "undefined is not an object (evaluating '_this2.refs.TextInputView')
一如既往:感谢您的帮助
as always: thanks for your help
推荐答案
好吧,您可以通过将与提交相关的所有内容保留在场景本身中来实现.
Well, you can do it by keeping everything related to the submission in the scene itself.
怎么样?
您可以通过在导航栏中按需注入按钮来实现.
You do it by injecting a button in the navbar on-demand.
这是我为我正在处理的项目创建的解决方案:https://rnplay.org/apps/dS31zw
Here's a solution I created for a project I'm working on: https://rnplay.org/apps/dS31zw
这个想法是为导航栏路由提供一个具有标签和功能的对象(以及您喜欢的任何东西......例如图标.)
The idea is to supply the navbar route with an object that has a label and a function (and whatever you like.. e.g. icons.)
作为奖励,您也可以注入标题!
As a bonus, you can inject the title too!
注意:这个技巧依赖于在 NavigationBarRouteMapper 工作之前调用的 componentWillMount().日后若有此变,必定破之.但它现在完美无缺!
Note: this trick depends on componentWillMount() being invoked before NavigationBarRouteMapper does it work. If this change in the future, it will definitely break it. But it works flawlessly now!
'use strict';
import React, {Component} from 'react';
import ReactNative from 'react-native';
const {
AppRegistry,
StyleSheet,
Text,
View,
Navigator,
Alert,
TouchableHighlight
} = ReactNative;
class Home extends Component {
//This trick depends on that componentWillMount fires before the navbar is created
componentWillMount() {
this.props.route.navbarTitle = "Home";
this.props.route.rightNavButton = {
text: "Button",
onPress: this._doSomething.bind(this)
};
}
_doSomething() {
Alert.alert(
'Awesome, eh?',
null,
[
{text: 'Indeed'},
]
)
}
render() {
return (
<View style={styles.container}>
<Text>You are home</Text>
</View>
);
}
}
class AppContainer extends Component {
renderScene(route, navigator) {
switch(route.name) {
case "Home":
//You must pass route as a prop for this trick to work properly
return <Home route={route} navigator={navigator} {...route.passProps} />
default:
return (
<Text route={route}
style={styles.container}>
Your route name is probably incorrect {JSON.stringify(route)}
</Text>
);
}
}
render() {
return (
<Navigator
navigationBar={
<Navigator.NavigationBar
style={ styles.navbar }
routeMapper={ NavigationBarRouteMapper } />
}
initialRoute={{ name: 'Home' }}
renderScene={ this.renderScene }
/>
);
}
}
//Nothing fancy here, except for checking for injected buttons.
var NavigationBarRouteMapper = {
LeftButton(route, navigator, index, navState) {
if(route.leftNavButton) {
return (
<TouchableHighlight
style={styles.leftNavButton}
underlayColor="transparent"
onPress={route.leftNavButton.onPress}>
<Text style={styles.navbarButtonText}>{route.leftNavButton.text}</Text>
</TouchableHighlight>
);
}
else if(route.enableBackButton) {
return (
<TouchableHighlight
style={styles.leftNavButton}
underlayColor="transparent"
onPress={() => navigator.pop() }>
<Text style={styles.navbarButtonText}>Back</Text>
</TouchableHighlight>
);
}
},
RightButton(route, navigator, index, navState) {
if(route.rightNavButton) {
return (
<TouchableHighlight
style={styles.rightNavButton}
underlayColor="transparent"
onPress={route.rightNavButton.onPress}>
<Text style={styles.navbarButtonText}>{route.rightNavButton.text}</Text>
</TouchableHighlight>
);
}
},
Title(route, navigator, index, navState) {
return (<Text style={styles.navbarTitle}>{route.navbarTitle || route.name}</Text>);
}
};
var styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#F5FCFF',
marginTop: 66
},
navbar: {
backgroundColor: '#ffffff',
},
navbarTitle: {
marginVertical: 10,
fontSize: 17
},
leftNavButton: {
marginVertical: 10,
paddingLeft: 8,
},
rightNavButton: {
marginVertical: 10,
paddingRight: 8,
},
navbarButtonText: {
fontSize: 17,
color: "#007AFF"
}
});
AppRegistry.registerComponent('AppContainer', () => AppContainer);
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