React Native控件之View视图讲解(7) | React Native学习指南

# # 转载请标明出处： [http://blog.csdn.net/developer_jiangqq/article/details/50540718](http://blog.csdn.net/developer_jiangqq/article/details/50540718) 本文出自:[【江清清的博客】](http://blog.csdn.net/developer_jiangqq) # (一)前言【好消息】个人网站已经上线运行,后面博客以及技术干货等精彩文章会同步更新，请大家关注收藏:[http://www.lcode.org](http://www.lcode.org/) 现在几讲我们对于React Native一些基础做了相关讲解(例如:环境搭建,开发IDE,调试以及升级降级等)，今天开始正式进入UI相关组件学习的阶段了。首先我们来讲一个非常基础的组件View。刚创建的React Native技术交流群(282693535),欢迎各位大牛,React Native技术爱好者加入交流!同时博客左侧欢迎微信扫描关注订阅号,移动技术干货,精彩文章技术推送! # (二)View组件介绍 View作为创建UI时候的最基础，最常用的组件。这边的View组件是支持FlexBox布局([对于FlexBox布局的详细使用讲解，请点击](http://www.w3cplus.com/css3/a-guide-to-flexbox.html))，CSS样式以及相关触摸处理的容器组件。该组件我们可以嵌套在其他视图View里边，并且可以包含很多种类型的子视图。在Web,Android，iOS三种平台上面该View视图可以对应平台中的三种原生视图，其中iOS对于UIView ，Web端对应<div>标签，Android对于android.view。下面我们来看一个比较简单的实例: ~~~ 'use strict'; var React = require('react-native'); var { AppRegistry, View, } = React; var TestText = React.createClass({ render: function() { return ( <View style={{flexDirection:'row',padding:20,height:100}}> <View style={{backgroundColor:'red',flex:1}}> </View> </View> ); } }); ~~~ 上述例子,我们这般首先创建了一个View，该View高度为100 ，但是该View的padding为20，所以整体效果如下: ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-02-29_56d3fbfe4d31c.jpg) 如果把padding修改成margin:20的话，那么是效果如下: ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-02-29_56d3fbfe5f4f7.jpg) 这个相信做过CSS ,原生布局开发的话，大家应该都能看得懂的。其实ReactNative开发，View设计的时候，也支持我们采用StyleSheet来进行书写控件的的布局，这样的话，我们的代码会更加的清晰以及便于维护了。其实React Native开发也更加推荐这种方式，下面我们采用StyleSheet来实现一下: ~~~ 'use strict'; var React = require('react-native'); var { AppRegistry, View, StyleSheet, } = React; var TestText = React.createClass({ render: function() { return ( <View style={styles.first_view}> <View style={styles.second_view}> </View> </View> ); } }); var styles = StyleSheet.create({ first_view:{ flexDirection:'row', height:100, padding:20 }, second_view: { backgroundColor:'red', flex:1 }, }); AppRegistry.registerComponent('TestText', () => TestText); ~~~ 以上的代码我们发现使用StyleSheet，进行创建相关styles，然后赋值给styles对象，在控件中直接styles对象进行使用即可。还是比较OK的。 # (三)View属性方法介绍 View属性方法介绍如下: <table border="1" cellpadding="0" cellspacing="0" valign="top" style="direction:ltr; border-collapse:collapse;border-style:solid;border-color:#A3A3A3;border-width: 1pt"><tbody><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6673in;padding:2.0pt 3.0pt 2.0pt 3.0pt">序号</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.4479in;padding:2.0pt 3.0pt 2.0pt 3.0pt">名称</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.8402in;padding:2.0pt 3.0pt 2.0pt 3.0pt">属性Or方法</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6805in;padding:2.0pt 3.0pt 2.0pt 3.0pt">类型</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:5.2451in;padding:2.0pt 3.0pt 2.0pt 3.0pt">说明</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6673in;padding:2.0pt 3.0pt 2.0pt 3.0pt">1</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.4479in;padding:2.0pt 3.0pt 2.0pt 3.0pt">accessibilityLabel</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.8215in;padding:2.0pt 3.0pt 2.0pt 3.0pt">属性</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6805in;padding:2.0pt 3.0pt 2.0pt 3.0pt">string</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:5.2645in;padding:2.0pt 3.0pt 2.0pt 3.0pt"> </td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6673in;padding:2.0pt 3.0pt 2.0pt 3.0pt">2</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.4479in;padding:2.0pt 3.0pt 2.0pt 3.0pt">accessible</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.8215in;padding:2.0pt 3.0pt 2.0pt 3.0pt">属性</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6805in;padding:2.0pt 3.0pt 2.0pt 3.0pt">bool</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:5.2645in;padding:2.0pt 3.0pt 2.0pt 3.0pt">当为trues时，表示该元素是可以进行访问，默认情况下 所有可触摸的元素控件都是可以访问的</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6673in;padding:2.0pt 3.0pt 2.0pt 3.0pt">3</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.4479in;padding:2.0pt 3.0pt 2.0pt 3.0pt">onAccessibilityTap</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.8215in;padding:2.0pt 3.0pt 2.0pt 3.0pt">方法</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6805in;padding:2.0pt 3.0pt 2.0pt 3.0pt">function</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:5.4597in;padding:2.0pt 3.0pt 2.0pt 3.0pt">该党accessible有true的时候并且用户对控件View做了一个Tap(轻轻的触摸或者点击)的手势</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6673in;padding:2.0pt 3.0pt 2.0pt 3.0pt">4</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.4479in;padding:2.0pt 3.0pt 2.0pt 3.0pt">onLayout</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.8215in;padding:2.0pt 3.0pt 2.0pt 3.0pt">方法</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6805in;padding:2.0pt 3.0pt 2.0pt 3.0pt">function</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:5.5631in;padding:2.0pt 3.0pt 2.0pt 3.0pt">当组件的布局发生变动的时候，会自动调用下面的方法: {nativeEvent: { layout: {x, y, width, height}}}。该事件当重新计算布局的时候会立即进行触发，不过界面可能不会立即刷新，特别当布局动画正在加载中的时候。</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6673in;padding:2.0pt 3.0pt 2.0pt 3.0pt">5</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.4479in;padding:2.0pt 3.0pt 2.0pt 3.0pt">onMagicTap</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.8215in;padding:2.0pt 3.0pt 2.0pt 3.0pt">方法</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:.6805in;padding:2.0pt 3.0pt 2.0pt 3.0pt">function</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:5.3756in;padding:2.0pt 3.0pt 2.0pt 3.0pt">当accessible为true的时候，当用户双指点击(Magic Tap)的时候，进行触发</td> </tr></tbody></table> 其他的一些方法如下(下面很多是关于事件响应者链的，基本都是比较简单的，就不着重讲解的，有兴趣大家都可以去测试一下): onMoveShouldSetResponder，onMoveShouldSetResponderCapture,onPresponderGrant,onResponderMove,onResponderReject,onResponderRelease,onResponderTerminate,onResponderTerminationRequest,onStartShouldSetResponder,onStartShouldSetResponderCapture,pointerEvents enum('box-none', 'none', 'box-only', 'auto')(触摸事件是否可以进行穿透控件View); removeClippedSubviews:该控件由于进行优化性能，尤其在一些滑动控件上面。该属性生效的要求如下:首先子视图的内容非常多，已经超过父容器，并且子视图和付容器视图都有overflow:hidden风格样式。【注】关于上面一些方法的具体使用，后面在讲到事件响应者的时候会进行着重讲解。 # (四)View风格Style介绍在React Native中的Style风格布局，其实和CSS样式有很多相似的地方，这边介绍一下: <table border="1" cellpadding="0" cellspacing="0" valign="top" style="direction:ltr; border-collapse:collapse;border-style:solid;border-color:#A3A3A3;border-width: 1pt"><tbody><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.3125in;padding:2.0pt 3.0pt 2.0pt 3.0pt">Style标签</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:3.6006in;padding:2.0pt 3.0pt 2.0pt 3.0pt">说明</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.2604in;padding:2.0pt 3.0pt 2.0pt 3.0pt"> Style标签</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:2.7076in;padding:2.0pt 3.0pt 2.0pt 3.0pt">说明</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.3125in;padding:2.0pt 3.0pt 2.0pt 3.0pt">FlexBox</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:3.6006in;padding:2.0pt 3.0pt 2.0pt 3.0pt">弹性布局(<a target="_blank" href="http://www.ruanyifeng.com/blog/2015/07/flex-grammar.html">详细点击了解</a>)</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.2604in;padding:2.0pt 3.0pt 2.0pt 3.0pt">transforms</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:2.7076in;padding:2.0pt 3.0pt 2.0pt 3.0pt">动画属性(<a target="_blank" href="http://facebook.github.io/react-native/docs/transforms.html#proptypes">详细点击了解</a>)</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.3125in;padding:2.0pt 3.0pt 2.0pt 3.0pt">backfaceVisibility</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:3.6006in;padding:2.0pt 3.0pt 2.0pt 3.0pt">enum('visible', 'hidden')定义界面翻转的时候是否可见</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.2798in;padding:2.0pt 3.0pt 2.0pt 3.0pt">backgroundColor</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:2.6881in;padding:2.0pt 3.0pt 2.0pt 3.0pt">背景颜色</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.3125in;padding:2.0pt 3.0pt 2.0pt 3.0pt">borderColor</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:3.6201in;padding:2.0pt 3.0pt 2.0pt 3.0pt">边跨颜色,这边几个就是代表上下左右变宽的颜色 borderTopColor,borderRightColor,borderBottomColor,borderLeftColor</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.2604in;padding:2.0pt 3.0pt 2.0pt 3.0pt">borderRadius</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:2.9236in;padding:2.0pt 3.0pt 2.0pt 3.0pt">边框圆角大小，其他几个是上下左右边框的圆角.borderTopLeftRadius,borderTopRightRadius,borderBottomLeftRadius, borderBottomRightRadius</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.3125in;padding:2.0pt 3.0pt 2.0pt 3.0pt">borderStyle</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:3.6006in;padding:2.0pt 3.0pt 2.0pt 3.0pt">边框线的风格,这个和CSS样式一样的,enum('solid', 'dotted', 'dashed')</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.2604in;padding:2.0pt 3.0pt 2.0pt 3.0pt">borderWidth</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:2.9055in;padding:2.0pt 3.0pt 2.0pt 3.0pt">边框宽度，另外四个是上下左右的边框宽度:borderTopWidth，borderRightWidth，borderBottomWidth，borderLeftWidth</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.3125in;padding:2.0pt 3.0pt 2.0pt 3.0pt">opacity</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:3.6006in;padding:2.0pt 3.0pt 2.0pt 3.0pt">设置透明度</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.2604in;padding:2.0pt 3.0pt 2.0pt 3.0pt">overflow</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:2.7076in;padding:2.0pt 3.0pt 2.0pt 3.0pt">设置内容超过容器显示还是隐藏</td> </tr><tr><td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.3125in;padding:2.0pt 3.0pt 2.0pt 3.0pt">elevation</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:3.6006in;padding:2.0pt 3.0pt 2.0pt 3.0pt">高度，设置Z轴，可以产生立体效果</td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:1.2604in;padding:2.0pt 3.0pt 2.0pt 3.0pt"> </td> <td style="border-style:solid;border-color:#A3A3A3;border-width:1pt; vertical-align:top;width:2.7076in;padding:2.0pt 3.0pt 2.0pt 3.0pt"> </td> </tr></tbody></table> 下面是几个特殊的属性，这边直接介绍所有平台通用以及只在Android平台有效果的属性 ①.testID (全平台) 可以根据该testID在测试的时候定位该View ②:accessibilityComponentType(android平台) 定义是否该UI组件和原生组件一致化处理 ③.accessibilityLiveRegion enum('none','polite','assertive') (android平台) 该当View发生更新时候的，是否需要通过用户，不过该只对Android4.4以及以上的平台设备有效果 ④.collapsable (android平台) 布局合并优化使用 ⑤.importantForAccessibility enum('auto','yes', 'no', 'no-hide-descendants') (android平台) 设置视图响应事件等级 ⑥.needsOffscreenAlphaCompositing (android平台) 设置View是否需要渲染和半透明度效果处理的先后次序。 ⑦.renderToHardwareTextureAndroid (android) 设置是否需要GPU进行渲染最后实例的官方实例为:[https://github.com/facebook/react-native/blob/master/Examples/UIExplorer/ViewExample.js](https://github.com/facebook/react-native/blob/master/Examples/UIExplorer/ViewExample.js) # (五)最后总结今天我们主要介绍了基础控件View的使用方法以及相关属性风格，大家有问题可以加一下群React Native技术交流群(282693535)或者底下进行回复一下。尊重原创，转载请注明：From Sky丶清（[http://blog.csdn.net/developer_jiangqq](http://blog.csdn.net/developer_jiangqq)）侵权必究！关注我的订阅号(codedev123),每天分享移动开发技术(Android/IOS),项目管理以及博客文章!(欢迎关注，第一时间推送精彩文章) ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-02-29_56d3fbf75e010.jpg) 关注我的微博，可以获得更多精彩内容 [![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-02-29_56d3fbf76bdef.png)](http://weibo.com/u/1855428195?s=6uyXnP)