最近对React Native比较有兴趣,简单把官网的入门例子做了一下,发现了很多坑,特别是watchman版本过低的问题,导致总是运行不起来。所以 这里特别下载了最新的watchman,进行了源码编译。希望本文对刚学习的新人有用。
安装Rect Native
安装必要的依赖watchman
cd watchman-4.5.0
./autogen.sh
./configure --prefix=/usr/local/Cellar/watchman/2.9.8 --with-pcre
make
make install
安装Rect Native开发工具
npm install -g react-native-cli
react-native init <APP_NAME>
IOS版本的项目文件用XCODE打开<APP_NAME>/ios/<APP_NAME>.xcodeproj,运行⌘+R即可
此时通过修改index.ios.js 运行⌘+R查看视图变化
模拟数据
通常在index.ios.js或index.android.js 顶部增加
var MOCKED_MOVIES_DATA = [
{title: 'Title', year: '2015', posters: {thumbnail: 'http://i.imgur.com/UePbdph.jpg'}},
];
修改代码,增加Image组件支持
import React, {
AppRegistry,
Component,
Image,
StyleSheet,
Text,
View
} from 'react-native';
修改render
render() {
var movie = MOCKED_MOVIES_DATA[0];
return (
<View style={styles.container}>
<Text>{movie.title}</Text>
<Text>{movie.year}</Text>
<Image
source={{uri: movie.posters.thumbnail}}
style={styles.thumbnail} />
</View>
);
}
更新样式代码
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#F5FCFF',
},
thumbnail: {
width: 53,
height: 81,
}
});
Xcode中⌘+R重新载入,即看到视图已载入我们的模拟数据。
重新布局
使用FlexBox布局
改变结构代码
render() {
var movie = MOCKED_MOVIES_DATA[0];
return (
<View style={styles.container}>
<Image
source={{uri: movie.posters.thumbnail}}
style={styles.thumbnail} />
<View style={styles.rightContainer}>
<Text style={styles.title}>{movie.title}</Text>
<Text style={styles.year}>{movie.year}</Text>
</View>
</View>
);
}
更新样式
const styles = StyleSheet.create({
container: {
flex: 1,
flexDirection: 'row',
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#F5FCFF',
},
rightContainer: {
flex: 1,
},
title: {
fontSize: 20,
marginBottom: 8,
textAlign: 'center',
},
year: {
textAlign: 'center',
},
thumbnail: {
width: 53,
height: 81,
}
});
获取真实的数据
添加API数据地址
var REQUEST_URL = 'https://raw.githubusercontent.com/facebook/react-native/master/docs/MoviesExample.json';
完整代码
'use strict';
import React, {
AppRegistry,
Component,
Image,
StyleSheet,
Text,
View
} from 'react-native';
var REQUEST_URL = 'https://raw.githubusercontent.com/facebook/react-native/master/docs/MoviesExample.json';
class FaceMash extends Component {
constructor(props){
super(props);
this.state = {
movies: null,
};
}
componentDidMount(){
this.fetchData();
}
fetchData(){
fetch(REQUEST_URL)
.then((response)=>response.json())
.then((responseData)=>{
this.setState({
movies: responseData.movies,
});
})
.done();
}
render() {
if(!this.state.movies){
return this.renderLoadingView();
}
var movie = this.state.movies[0];
return this.renderMovie(movie);
}
renderLoadingView(){
return (
<View style={styles.container}>
<Text>
Loading movies...
</Text>
</View>
);
}
renderMovie(movie){
return (
<View style={styles.container}>
<Image
source={{uri: movie.posters.thumbnail}}
style={styles.thumbnail} />
<View style={styles.rightContainer}>
<Text style={styles.title}>{movie.title}</Text>
<Text style={styles.year}>{movie.year}</Text>
</View>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
flexDirection: 'row',
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#F5FCFF',
},
rightContainer: {
flex: 1,
},
title: {
fontSize: 20,
marginBottom: 8,
textAlign: 'center',
},
year: {
textAlign: 'center',
},
thumbnail: {
width: 53,
height: 81,
}
});
AppRegistry.registerComponent('FaceMash', () => FaceMash);
显示列表
/**
* Sample React Native App
* https://github.com/facebook/react-native
*/
'use strict';
import React, {
AppRegistry,
Component,
Image,
ListView,
StyleSheet,
Text,
View
} from 'react-native';
var API_KEY='7waqfqbprs7pajbz28mqf6vz';
var API_URL = 'http://api.rottentomatoes.com/api/public/v1.0/lists/movies/in_theaters.json';
var PAGE_SIZE = 25;
var PARAMS = '?apikey='+API_KEY+'&page_limit='+PAGE_SIZE;
var REQUEST_URL = API_URL+PARAMS;
class FaceMash extends Component {
constructor(props){
super(props);
this.state = {
dataSource: new ListView.DataSource({
rowHasChanged: (row1, row2) => row1 !== row2,
}),
loaded: false,
};
}
componentDidMount(){
this.fetchData();
}
fetchData(){
fetch(REQUEST_URL)
.then((response)=>response.json())
.then((responseData)=>{
this.setState({
dataSource: this.state.dataSource.cloneWithRows(responseData.movies),
loaded: true,
});
})
.done();
}
render() {
if(!this.state.loaded){
return this.renderLoadingView();
}
return (
<ListView
dataSource={this.state.dataSource}
renderRow={this.renderMovie}
style={styles.listView}>
</ListView>
);
}
renderLoadingView(){
return (
<View style={styles.container}>
<Text>
Loading movies...
</Text>
</View>
);
}
renderMovie(movie){
return (
<View style={styles.container}>
<Image
source={{uri: movie.posters.thumbnail}}
style={styles.thumbnail} />
<View style={styles.rightContainer}>
<Text style={styles.title}>{movie.title}</Text>
<Text style={styles.year}>{movie.year}</Text>
</View>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
flexDirection: 'row',
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#F5FCFF',
},
listView: {
paddingTop: 20,
backgroundColor: '#F5FCFF',
},
rightContainer: {
flex: 1,
},
title: {
fontSize: 20,
marginBottom: 8,
textAlign: 'center',
},
year: {
textAlign: 'center',
},
thumbnail: {
width: 53,
height: 81,
}
});
AppRegistry.registerComponent('FaceMash', () => FaceMash);