这一章我参考的资源很多,官网的navigator、navigation、UIExplorer的navigatorExample,因此会涉及到非常多的es6语法,尽量一一记录下来。
最小化代码
import React, {Component} from 'react';
import SplashScreen from 'react-native-splash-screen';
import {AppRegistry, Text, Navigator} from 'react-native';
const sleep = require('es6-sleep').promise;
export default class NavAllDay extends Component {
async sleep(milliansecond) {
await sleep(milliansecond);
}
async componentDidMount() {
// do anything while splash screen keeps, use await to wait for an async task.
await sleep(2000);
await SplashScreen.hide();
}
render() {
return (<Navigator initialRoute={{ title: 'Awesome Scene', index: 0 }}
renderScene={(route, navigator) => <Text>Hello {route.title}!</Text> }
style={{padding: 100}}/> );
}
}
AppRegistry.registerComponent('rn_practice', () => NavAllDay);
Navigator参数:
initialRoute
: 类似MVC框架中的urls这一层,表明当前这个Navigator有多少个路径,每个路径表示一个可切换的场景。
renderScene
: 类似MVC框架中的template这一层,每次触发场景切换时将定义的变量传递过来进行重新渲染。
备注: 上面这段代码不会有任何很直观的效果,因为只有一个route,没有切换,因此感觉不出来它的特性,下面逐量去增加代码。
两条路由
import React, {Component} from 'react';
import SplashScreen from 'react-native-splash-screen';
import {AppRegistry, Text, Navigator, TouchableHighlight} from 'react-native';
const sleep = require('es6-sleep').promise;
export default class NavAllDay extends Component {
async sleep(milliansecond) {
await sleep(milliansecond);
}
async componentDidMount() {
// do anything while splash screen keeps, use await to wait for an async task.
await sleep(2000);
await SplashScreen.hide();
}
render() {
const routes = [
{title: 'First Scene', index: 0},
{title: 'Second Scene', index: 1}
];
return (<Navigator
initialRoute={routes[0]}
renderScene={
(route, navigator) =>
<Text onPress={() => {
if (route.index == 0) {
navigator.push(routes[route.index+1])
} else {
navigator.pop()
}}
}>
Hello {route.title} !
</Text>
}
/>
);
}
}
AppRegistry.registerComponent('rn_practice', () => NavAllDay);
备注: 这里利用了Text组件的onPress来触发状态的切换,也就是说当我点击这个文本内容时,就会切换到另外一个文本。
多条路由
import React, {Component, PropTypes} from 'react';
import SplashScreen from 'react-native-splash-screen';
import {View, Text, TouchableHighlight, AppRegistry, Navigator} from 'react-native';
const sleep = require('es6-sleep').promise;
export default class MyScene extends Component {
render() {
return (
<View>
<Text>Current Scene: {this.props.title}</Text>
<Text onPress={this.props.onForward}>Tap me to load the next scene</Text>
<Text onPress={this.props.onBack}>Tap me to go back</Text>
</View> )
}
}
MyScene.propTypes = {
title: PropTypes.string.isRequired,
onForward: PropTypes.func.isRequired,
onBack: PropTypes.func.isRequired,
};
class SimpleNavigationApp extends Component {
async sleep(milliansecond) {
await sleep(milliansecond);
}
async componentDidMount() {
// do anything while splash screen keeps, use await to wait for an async task.
await sleep(2000);
await SplashScreen.hide();
}
render() {
return (
<Navigator
initialRoute={{ title: 'My Initial Scene', index: 0 }}
renderScene={(route, navigator) =>
<MyScene title={route.title}
onForward={() => {
const nextIndex = route.index + 1;
navigator.push({ title: 'Scene ' + nextIndex, index: nextIndex, }); }}
onBack={() => {
if (route.index > 0) { navigator.pop(); }
}}
/>
}
/>
)
}
}
AppRegistry.registerComponent('rn_practice', () => SimpleNavigationApp);
propTypes
是用来声明当前对象所需要的参数类型和是否必填,一般用于开发调试(注释掉不影像任何功能),线上产品不要使用propTypes因为它会影像性能和提出警告,官方详细说明。
MyScene
这个对象内容很简单,直接就返回一个View里面包裹这三个Text,在react中,它会将MyScene当作一个组件对象,可以直接用在JSX中,例如<MyScene />。
备注: 在这个例子中,并没有提前定义总共有多少个routes,只定义了initialRoute的数据格式,然后所有的操作都在renderScene里面去动态的控制,也就是说通过这种方式可以无限点击和无限操作。
装饰(宽和高)--多条路由
import React, {Component, PropTypes} from 'react';
import SplashScreen from 'react-native-splash-screen';
import {View, Text, TouchableHighlight, AppRegistry, Navigator, StyleSheet} from 'react-native';
const sleep = require('es6-sleep').promise;
export default class MyScene extends Component {
render() {
return (
<View>
<View style={styles.row_title}>
<Text>Current Scene: {this.props.title}</Text>
</View>
<View style={styles.row_items}>
<Text onPress={this.props.onForward}>Tap me to load the next scene</Text>
</View>
<View style={styles.row_items}>
<Text onPress={this.props.onBack}>Tap me to go back</Text>
</View>
</View> )
}
}
class SimpleNavigationApp extends Component {
async sleep(milliansecond) {
await sleep(milliansecond);
}
async componentDidMount() {
// do anything while splash screen keeps, use await to wait for an async task.
await sleep(2000);
await SplashScreen.hide();
}
render() {
return (
<Navigator
initialRoute={{ title: 'My Initial Scene', index: 0 }}
renderScene={(route, navigator) =>
<MyScene title={route.title}
onForward={() => {
const nextIndex = route.index + 1;
navigator.push({ title: 'Scene ' + nextIndex, index: nextIndex, }); }}
onBack={() => {
if (route.index > 0) { navigator.pop(); }
}}
/>
}
configureScene={(route, navigator) => Navigator.SceneConfigs.HorizontalSwipeJump}
/>
)
}
}
const styles = StyleSheet.create({
row_items: {
padding: 20,
borderBottomWidth: 1 / 3,
borderBottomColor:'#CDCDCD',
},
row_title: {
height: 50,
borderBottomWidth: 1 / 3,
borderBottomColor:'#CDCDCD',
justifyContent: 'center',
alignItems: 'center'
}
});
AppRegistry.registerComponent('rn_practice', () => SimpleNavigationApp);
StyleSheet
加点样式跟没有样式,确实不一样哈,好看多了。
configureScene
这是Navigator组件其中的一个参数,它的用途是配置切换的效果,这里列出了可配置范围。
- Navigator.SceneConfigs.PushFromRight (default)
- Navigator.SceneConfigs.FloatFromRight
- Navigator.SceneConfigs.FloatFromLeft
- Navigator.SceneConfigs.FloatFromBottom
- Navigator.SceneConfigs.FloatFromBottomAndroid
- Navigator.SceneConfigs.FadeAndroid
- Navigator.SceneConfigs.SwipeFromLeft
- Navigator.SceneConfigs.==HorizontalSwipeJump== # 这个牛逼, 采用这个配置之后,在屏幕任意地方左划或又划分别标识前进和后退,但是前提是要存在多个routes,否则划不过去。
- Navigator.SceneConfigs.HorizontalSwipeJumpFromRight
- Navigator.SceneConfigs.HorizontalSwipeJumpFromLeft
- Navigator.SceneConfigs.VerticalUpSwipeJump
- Navigator.SceneConfigs.VerticalDownSwipeJump
装饰(material circle)--多条路由
import React, {Component, PropTypes} from 'react';
import SplashScreen from 'react-native-splash-screen';
import {View, Text, TouchableHighlight, AppRegistry, Navigator, StyleSheet, TouchableNativeFeedback} from 'react-native';
const sleep = require('es6-sleep').promise;
export default class MyScene extends Component {
render() {
return (
<View>
<View style={styles.row_title}>
<Text>Current Scene: {this.props.title}</Text>
</View>
<TouchableNativeFeedback
background={TouchableNativeFeedback.SelectableBackground()}
onPress={this.props.onForward}>
<View style={styles.row_items}>
<Text>
Enabled TouchableNativeFeedback
</Text>
</View>
</TouchableNativeFeedback>
<TouchableNativeFeedback
background={TouchableNativeFeedback.SelectableBackground()}
onPress={this.props.onBack}>
<View style={styles.row_items}>
<Text>Tap me to go back</Text>
</View>
</TouchableNativeFeedback>
</View> )
}
}
class SimpleNavigationApp extends Component {
async sleep(milliansecond) {
await sleep(milliansecond);
}
async componentDidMount() {
// do anything while splash screen keeps, use await to wait for an async task.
await sleep(2000);
await SplashScreen.hide();
}
render() {
return (
<Navigator
initialRoute={{ title: 'My Initial Scene', index: 0 }}
renderScene={(route, navigator) =>
<MyScene title={route.title}
onForward={() => {
const nextIndex = route.index + 1;
navigator.push({ title: 'Scene ' + nextIndex, index: nextIndex, }); }}
onBack={() => {
if (route.index > 0) { navigator.pop(); }
}}
/>
}
configureScene={(route, navigator) => Navigator.SceneConfigs.HorizontalSwipeJump}
/>
)
}
}
const styles = StyleSheet.create({
row_items: {
padding: 20,
borderBottomWidth: 1 / 3,
borderBottomColor:'#CDCDCD',
},
row_title: {
height: 50,
borderBottomWidth: 1 / 3,
borderBottomColor:'#CDCDCD',
justifyContent: 'center',
alignItems: 'center'
},
});
AppRegistry.registerComponent('rn_practice', () => SimpleNavigationApp);
腾讯新闻APP中的新闻列表,当我长按某一条新闻列表是,会出现一个底色为灰色的圆圈慢慢扩大一直灰色到把整行给覆盖掉,这个特性采用的是TouchableNativeFeedback
,是google的material设计风格。
注意: 我在调试这个功能,代码已经写好了但是一直都没有出现NativeFeedback这个特效,反复折腾了好久才发现原来是我在Text组件中用了onPress,导致与TouchableNativeFeedback相互冲突了,所以我把Text中的onPress移除掉,将相关的状态切换代码写到TouchableNativeFeedback组件的onPress中。
两个navigator
一个是导航,另外一个是列表