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转载链接:http://www.ncloud.hk/%E6%8A%80%E6%9C%AF%E5%88%86%E4%BA%AB/react-native-component-packaging-and-traditional-values/
刚接触React-Native的时候也是看官方文档，官方文档就是讲的基础的组件与与基础的API,然后就开始写一些简单的界面，但是发现自己写的简单界面代码非常的长，修改起来也是非常的麻烦，维护起来非常的费尽。那么今天就简单的介绍一下组件的封装和传值吧。你会发现节省了好多的代码。
效果图:(如下所示)
一、先说说没有封装之前的代码是什么样子的吧。
‘use strict‘;
var React = require(‘react-native‘);
var {
AppRegistry,
StyleSheet,
Text,
View,
PixelRatio,
} = React;
var stylesForXC = StyleSheet.create({
container : {
height: 84,
borderWidth:1,
borderColor: ‘black‘,
flexDirection: ‘row‘,
marginTop: 25,
marginLeft: 5,
marginRight: 5,
borderRadius: 5, /*圆角半径*/
padding: 2,
backgroundColor: ‘#949494‘
},
item: {
flex: 1,
height: 80
},
flex: {
flex: 1
},
center: {
justifyContent: ‘center‘,/*垂直水平居中，其实是按照flexDriection的方向居中*/
alignItems : ‘center‘, /*水平居中*/
},
font : {
color: ‘#fff‘,
fontSize: 16,
fontWeight: ‘bold‘,
},
lineLeft: {
borderLeftWidth: 1/PixelRatio.get(),
borderColor: ‘#fff‘,
},
lineCenter: {
borderBottomWidth:1/PixelRatio.get(),
borderColor: ‘#fff‘,
}
})
‘use strict‘;
var React = require(‘react-native‘);
var {
AppRegistry,
StyleSheet,
Text,
View,
PixelRatio,
} = React;
var stylesForXC = StyleSheet.create({
container : {
height: 84,
borderWidth:1,
borderColor: ‘#949494‘,
flexDirection: ‘row‘,
marginTop: 25,
marginLeft: 5,
marginRight: 5,
borderRadius: 5, /*圆角半径*/
padding: 2,
backgroundColor: ‘#949494‘,
},
item: {
flex: 1,
height: 80,
},
flex: {
flex: 1,
},
center: {
justifyContent: ‘center‘,/*垂直水平居中，其实是按照flexDriection的方向居中*/
alignItems : ‘center‘, /*水平居中*/
},
font : {
color: ‘#fff‘,
fontSize: 16,
fontWeight: ‘bold‘,
},
lineLeft: {
borderLeftWidth: 1/PixelRatio.get(),
borderColor: ‘#fff‘,
},
lineCenter: {
borderBottomWidth:1/PixelRatio.get(),
borderColor: ‘#fff‘,
}
})
AppRegistry.registerComponent(‘wxsPrj‘, () => wxsPrj);
var betree2 = React.createClass({
render: function() {
return (
<View style = {stylesForXC.flex}>
<View style = {[stylesForXC.container]}>
<View style = {[stylesForXC.item,stylesForXC.center]}>
<Text style= {stylesForXC.font}>饭馆</Text>
</View>
<View style = {[stylesForXC.item,stylesForXC.lineLeft]}>
<View style = {[stylesForXC.center,stylesForXC.flex,stylesForXC.lineCenter]}>
<Text style= {stylesForXC.font}>服装城</Text>
</View>
<View style = {[stylesForXC.center,stylesForXC.flex]}>
<Text style= {stylesForXC.font}>美食街</Text>
</View>
</View>
<View style = {[stylesForXC.item,stylesForXC.lineLeft]}>
<View style = {[stylesForXC.center,stylesForXC.flex,stylesForXC.lineCenter]}>
<Text style= {stylesForXC.font}>电脑城</Text>
</View>
<View style = {[stylesForXC.center,stylesForXC.flex]}>
<Text style= {stylesForXC.font}>全球购</Text>
</View>
</View>
</View>
</View>
);
}
})
AppRegistry.registerComponent(‘betree2‘, () => betree2);
我们发现在主函数上界面布局很多，这样不利于模块化的思想，我们其实可以把里面的界面的布局封装成一个名为Box的组件，然后在主函数中对组件进行引用，这样看起来就好多了。
二、封装组件后的代码如下:
render:function(){
return(
<View style = {stylesForXC.flex}>
<View style = {[stylesForXC.container]}>
<View style = {[stylesForXC.item,stylesForXC.center]}>
<Text style= {stylesForXC.font}>饭馆</Text>
</View>
<View style = {[stylesForXC.item,stylesForXC.lineLeft]}>
<View style = {[stylesForXC.center,stylesForXC.flex,stylesForXC.lineCenter]}>
<Text style= {stylesForXC.font}>服装城</Text>
</View>
<View style = {[stylesForXC.center,stylesForXC.flex]}>
<Text style= {stylesForXC.font}>美食街</Text>
</View>
</View>
<View style = {[stylesForXC.item,stylesForXC.lineLeft]}>
<View style = {[stylesForXC.center,stylesForXC.flex,stylesForXC.lineCenter]}>
<Text style= {stylesForXC.font}>电脑城</Text>
</View>
<View style = {[stylesForXC.center,stylesForXC.flex]}>
<Text style= {stylesForXC.font}>全球购</Text>
</View>
</View>
</View>
</View>
);
}
})
var betree2 = React.createClass({
render: function() {
return (
<Box></Box>
);
}
})
这样看起来把布局放进去，在主函数中调用就可以了，这样是不是就清晰很多了。有一点我们是需要注意的就是:这种定义的组件首字母一定要大写，不然会报错(如下图所示，意思就是说每个首字母的名字要大写，刚开始我也没注意这个细节)。
三、那么问题又来了，如果我想修改<Text>组件里面的内容(比如:‘全球购‘改为‘电脑馆‘),有人会说那好办自己找下里面的代码把‘‘全球购‘改为‘电脑馆‘不就可以了，那如果我成百个Text呢? 我们其实可以定义一个组件参数，这样就方便多了。代码如下:
var Box = React.createClass({
render:function(){
return(
<View style = {stylesForXC.flex}>
<View style = {[stylesForXC.container]}>
<View style = {[stylesForXC.item,stylesForXC.center]}>
<Text style= {stylesForXC.font}>{this.props.one}</Text>
</View>
<View style = {[stylesForXC.item,stylesForXC.lineLeft]}>
<View style = {[stylesForXC.center,stylesForXC.flex,stylesForXC.lineCenter]}>
<Text style= {stylesForXC.font}>{this.props.second1}</Text>
</View>
<View style = {[stylesForXC.center,stylesForXC.flex]}>
<Text style= {stylesForXC.font}>{this.props.second2}</Text>
</View>
</View>
<View style = {[stylesForXC.item,stylesForXC.lineLeft]}>
<View style = {[stylesForXC.center,stylesForXC.flex,stylesForXC.lineCenter]}>
<Text style= {stylesForXC.font}>{this.props.third1}</Text>
</View>
<View style = {[stylesForXC.center,stylesForXC.flex]}>
<Text style= {stylesForXC.font}>{this.props.third2}</Text>
</View>
</View>
</View>
</View>
);
}
})
var betree2 = React.createClass({
render: function() {
return (
<Box one = "饭馆" second1 = "服装城" second2 = "美食街" third1 = "电脑城" third2 = "全球购"></Box>
);
}
})
效果图如下所示:
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原文地址：http://www.cnblogs.com/635-99993/p/5200442.html
