React-native开发流程及问题整理

运行react-native出现的问题：

1、找不到Android-23 ，确定你sdk里边的内容是最新的，包含5.0及以上。

2、插入多个usb设备会导致安装失败，拔掉只留一个就好。

可以查看设备状态：（确认adb已经配置到path里边）

<pre name="code" class="java"><span style="font-size:18px;">$ adb devices
     List of devices attached
     emulator-5554 offline   # Google emulator
     14ed2fcc device         # Physical device</span>

如果启动程序出现白屏，那么就可能是一下几种情况：

（1）、若出现下边情况：

dyld: Library not loaded: /usr/local/lib/libpcre.1.dylib
  Referenced from: /usr/local/bin/watchman
  Reason: image not found

dyld: Library not loaded: /usr/local/lib/libpcre.1.dylib
  Referenced from: /usr/local/bin/watchman
  Reason: image not found

Watchman:  watchman--no-pretty get-sockname returned with exit code null dyld: Library not loaded: /usr/local/lib/libpcre.1.dylib
  Referenced from: /usr/local/bin/watchman
  Reason: image not found

 ERROR  watchman--no-pretty get-sockname returned with exit code null dyld: Library not loaded: /usr/local/lib/libpcre.1.dylib
  Referenced from: /usr/local/bin/watchman
  Reason: image not found

Error: watchman--no-pretty get-sockname returned with exit code null dyld: Library not loaded: /usr/local/lib/libpcre.1.dylib
  Referenced from: /usr/local/bin/watchman
  Reason: image not found

    at ChildProcess.<anonymous> (/Users/Jing/Projects/ReactNative/AwesomeProject/node_modules/react-native/node_modules/sane/node_modules/fb-watchman/index.js:194:18)
    at emitTwo (events.js:87:13)
    at ChildProcess.emit (events.js:172:7)
    at maybeClose (internal/child_process.js:817:16)
    at Socket.<anonymous> (internal/child_process.js:319:11)
    at emitOne (events.js:77:13)
    at Socket.emit (events.js:169:7)
    at Pipe._onclose (net.js:469:12)

是pcre找不到，通过如下命令即可修复：

$ brew uninstall pcre && brew install pcre 

	（2）、如果带一次运行都没有显示   加载js的那个界面，一般是你的手机悬浮窗选项被禁用了，

开启就好

	（3）、如果实现加载js的界面，但是加载完以后还是白屏，没有显示welcome 。。。。。。的那个界面，那么说明还有问题

是 Server 访问错误。参考官方文档。对于 Android 5.0 及以上的设备，直接运行：
    
    

     
     
 
      
$ adb reverse tcp:8081 tcp:8081 
 
     
    
    
我找来一个 Android 5.0 的机器，果然可以了。对于 5.0 以下的机器，上面的命令会出错：
    
    
$ adb reverse tcp:8081 tcp:8081 error: closed error: closed 

4、错误Couldnotget BatchedBridge,make sure your bundleispackaged correctly 

该错误具体原因不知道，但是可以解决，在项目的根目录下输入下边命令：

	react-native bundle --platform android --dev false --entry-fileindex.android.js --bundle-output android/app/src/main/assets/.android.bundle --sourcemap-output android/app/src/main/assets/.android.map--assets-dest android/app/src/main/res/

然后等命令执行完以后重新安装。

关于其中代码编写也就是他的开发流程介绍：

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React,{ Component } from 'react';
import {
  AppRegistry,StyleSheet,Text,View
} from 'react-native';

class HelloWorld extends Component {
  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>
          Welcome to React Native!
        </Text>
        <Text style={styles.instructions}>
          To get started,edit index.android.js
        </Text>
        <Text style={styles.instructions}>
          Double tap R on your keyboard to reload,{'n'}
          Shake or press menu button for dev menu
        </Text>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,justifyContent: 'center',alignItems: 'center',backgroundColor: '#F5FCFF',},welcome: {
    fontSize: 20,textAlign: 'center',margin: 10,instructions: {
    textAlign: 'center',color: '#333333',marginBottom: 5,});

AppRegistry.registerComponent('HelloWorld',() => HelloWorld);