1.怎样更换主体类:更换文件./App2，选取对应文件的类名LotsOfGreetings
import { AppRegistry } from 'react-native';
import {LotsOfGreetings} from './App2';
AppRegistry.registerComponent('AHelloWorld', () => LotsOfGreetings);
2.nvm管理node版本
To install or update nvm, you can use the install script using cURL:
curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh | bash
or Wget:
wget -qO- https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh | bash
The script clones the nvm repository to ~/.nvm and adds the source line to your profile (~/.bash_profile, ~/.zshrc, ~/.profile, or ~/.bashrc).
export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh" # This loads nvm
没有理解命令行open .profile
3.Unexpected token (30:33) (null))
语法有误，请检查当前行的语法
正确：placeholder = "开始编辑喜欢的内容"
错误：placeholder : "开始编辑喜欢的内容"
4.Unhandled JS Exception: Stylesheet is not defined
正确：StyleSheet
错误：Stylesheet
5.Unhandled JS Exception: "justifyItems" is not a valid style property.
正确：
alternativeLayoutButtonContainer: {
margin: 20,
flexDirection: 'row',
justifyContent: 'space-between'
}
错误：
alternativeLayoutButtonContainer: {
"margin": 20,
"flexDirection": "row",
"justifyItems": "space-between"
}
6.Unhandled JS Exception: ReferenceError: style is not defined
正确：<View style={styles.container}>
错误: <View style={style.container}>
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
},
buttonContainer: {
margin: 20
},
alternativeLayoutButtonContainer: {
margin: 20,
flexDirection: 'row',
justifyContent: 'space-between'
}
})
7._onPresssButton和_onPresssButton() 的区别
_onPresssButton点击时候调用，_onPresssButton()加载时候调用
<Button title="Press Me" onPress={this._onPresssButton}/>
箭头函数是什么鬼👻？ <Button title="Press Me" onPress={() => this._onPresssButton}/> 和 <Button title="Press Me" onPress={this._onPresssButton}/>作用相同，点击时候调用
8.Unhandled JS Exception: ReferenceError: Platform is not defined
import {
Image,
Text,
View,
TextInput,
Button,
**Platform**,
Alert,
StyleSheet,
TouchableHighlight,
TouchableOpacity,
TouchableNativeFeedback,
TouchableWithoutFeedback,
} from 'react-native';
9.引入json文件
const BadgeData = require('./BadgeData.json');
10.不显示图片资源,没有给Image资源大小
imageStyle: {
width:80,
height:80
},
11.Warning: Each child in an array or iterator should have a unique "key" prop.
正确：
<View key={i} style={styles.outViewStyle}>
<Image source={{uri: badge.icon}} style={styles.imageStyle}/>
<Text style={styles.titleStyle}>
{badge.title}
</Text>
</View>
错误：
<View style={styles.outViewStyle}>
<Image source={{uri: badge.icon}} style={styles.imageStyle}/>
<Text style={styles.titleStyle}>
{badge.title}
</Text>
</View>
12.注意：为了使新的图片资源机制正常工作，require中的图片名字必须是一个静态字符串（不能使用变量！因为require是在编译时期执行，而非运行时期执行！）。
// 正确
<Image source={require('./my-icon.png')} />
// 错误
var icon = this.props.active ? 'my-icon-active' : 'my-icon-inactive';
<Image source={require('./' + icon + '.png')} />
// 正确
var icon = this.props.active ? require('./my-icon-active.png') : require('./my-icon-inactive.png');
<Image source={icon} />
13.State的使用 ES5&ES6
ES6:
// 设置改变和初始值
constructor(props) {
super(props);
this.state = {
// 当前页码
currentPage : 0
}
}
// 当一帧滚动结束的时候
onMomentSrollEndSelf(event) {
// 1.求出水平方向偏移量
var offSetX = event.nativeEvent.contentOffset.x;
// 2.求出当前页数 -- 取整
var currentPage = Math.floor(offSetX / width);
// 3.更新状态机，重绘UI
this.setState({currentPage:currentPage})
}
ES5:
// 设置改变和初始值
getInitialState() {
return {
// 当前页码
currentPage: 0
}
}
14.Unhandled JS Exception: TypeError: _reactNative.ListView.dataSource is not a constructor
正确：
var ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 != r2});
错误：
var ds = new ListView.dataSource({rowHasChanged: (r1, r2) => r1 != r2});
15.Failed to load bundle(http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false) with error:(SyntaxError in /Users/Droi/Desktop/RN/AHelloWorld/App4.js: /Users/Droi/Desktop/RN/AHelloWorld/App4.js: Unexpected token (48:33) (null))
正确：
selected={this.state.selectedTabbarItem === 'home'}
错误：
selected:{this.state.selectedTabbarItem === 'second'}
16.Unhandled JS Exception: Invariant Violation: React.Children.only expected to receive a single React element child.
正确：
{/*首页*/}
<TabBarIOS.Item
// icon={require('tabbar_home')}
// icon={require('../assets/tabbar_home.png')}
title="首页"
icon={{uri: 'tabbar_home', scale:3}}
selected={this.state.selectedItem === 'home'}
onPress={() => {this.setState({selectedItem: 'home'})}}
>
<View></View>
</TabBarIOS.Item>
错误：
<TabBarIOS.Item
// icon={require('tabbar_home')}
// icon={require('../assets/tabbar_home.png')}
title="首页"
icon={{uri: 'tabbar_home', scale:3}}
selected={this.state.selectedItem === 'home'}
onPress={() => {this.setState({selectedItem: 'home'})}}
>
</TabBarIOS.Item>
17.根据平台适配TabBar
width: Platform.OS === 'ios' ? 30 : 25,
18.Unhandled JS Exception: Invariant Violation: React.Children.only expected to receive a single React element child.
正确：
<TabNavigator.Item
title="首页"
renderIcon={() => <Image source={require('../img/TabBar/tabbar_home.png')} style={styles.iconStyle}></Image>}
renderSelectedIcon={() => <Image source={require('../img/TabBar/tabbar_home_highlighted.png')} />}
selected={this.state.selectedTab === 'home'}
onPress={() => this.setState({ selectedTab: 'home' })}
>
<Home/>
</TabNavigator.Item>
错误：
<TabNavigator.Item
title="首页"
renderIcon={() => <Image source={require('../img/TabBar/tabbar_home.png')} style={styles.iconStyle}></Image>}
renderSelectedIcon={() => <Image source={require('../img/TabBar/tabbar_home_highlighted.png')} />}
selected={this.state.selectedTab === 'home'}
onPress={() => this.setState({ selectedTab: 'home' })}>
>
<Home/>
</TabNavigator.Item>
语法问题：在onPress行末尾的添加了">"，本不应该有的
19.The <Image> component cannot contain children. If you want to render content on top of the image, consider using aboslute positioning.
Good catch. I simple PR replacing Image with ImageBackground will fix this.
<ImageBackground
ref="backImage"
source={{uri: 'https://www.google.com/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png'}}
style={styles.backImageStyle}
// resizeMode='cover'
// resizeMode='contain'
resizeMode='center' // resizeMode: PropTypes.oneOf(['cover', 'contain', 'stretch', 'repeat', 'center']),
>
<Text style={styles.textStyle}>设置图片为背景</Text>
</ImageBackground>
20.组件之间的通信
this.props.imageDataArr,在自定义组件里面应该起到哪些作用？
props和state之前又怎样的关系？
{this.renderRow}和{(rowData) => this.renderRow(rowData)}又怎样的区别？
21.修改WebStorm空格个数 ===> 'detect indent'
屏幕快照 2018-01-05 上午11.52.27.png
22.Unhandled JS Exception: Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object.
正确：
import CommonCell from './ZHCommonCell';
错误：
let CommonCell = require('./ZHCommonCell');
export default class ZHCommonCell extends Component {
}
23.iphone X在RN里面进行适配一些比较蠢的暂时是配方法
style={{marginTop: ((parseInt(Platform.Version, 10) >= 11 && Platform.OS === 'ios') ? ((width == 375 && height == 812) ? -44 : -20) : 0)}}
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