react-native加入mobx 步骤，及出现的问题

1 初始化项目

react-native init mobxDemo

2 安装mobx

npm install mobx --save

3 安装mobx-react

npm install mobx-react --save

4.安装bable转码

npm install @babel/plugin-proposal-decorators

添加js文件

(1)appStre.js

import {observable,action} from 'mobx';
var appStore = observable({
    counter: 0
});
appStore.addCount = action(()=>{
    appStore.counter+=1;
});
appStore.subCount = action(()=>{
    if(appStore.counter<=0){
        return;
    }
    appStore.counter-=1;
});
appStore.changeCount = action((key)=>{
    if(key<=0){
        appStore.counter=0;
    }
    appStore.counter=parseInt(key);
});
export default appStore

(2)home.js

import React, {Component} from 'react';
import {Platform, StyleSheet, Text, View,TouchableOpacity,TextInput} from 'react-native';
import {observer, inject} from 'mobx-react';

@inject('store')
@observer
export default class Home extends Component{
    constructor(props){
        super(props);
        this.state={
            value:0
        }
    }
    componentWillMount(){
        console.log(this.props.store.counter)
    }
    sub=()=>{
        let {store}=this.props;
        store.subCount()
    }
    add=()=>{
        let {store}=this.props;
        store.addCount()
    }
    render() {
        let {store}=this.props
        return (
        
            
                -  
            
            
            
                +  
               
        
        );
    }
}

const styles = StyleSheet.create({
    container:{
        flex:1,
        flexDirection:'row',
        alignItems:'center',
        justifyContent:'center'
    }
});

(3) app.js

import React, {Component} from 'react';
import {Platform, StyleSheet, Text, View} from 'react-native';
import {Provider} from 'mobx-react'
import AppStore from './js/Mobx/appStore'
import Home from './js/pages/home'
const instructions = Platform.select({
  ios: 'Press Cmd+R to reload,\n' + 'Cmd+D or shake for dev menu',
  android:
    'Double tap R on your keyboard to reload,\n' +
    'Shake or press menu button for dev menu',
});

export default class App extends Component{
  render() {
    return (
      
        
      
    );
  }
}

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,
  },
});

(4).babelrc（注意：react-native 0.57版本之后将全面升级babel 7，babel 6 将无法运行）

{
"presets": ["module:metro-react-native-babel-preset"],
"plugins": [
    ["@babel/plugin-proposal-decorators", { "legacy": true }],
    ["@babel/transform-runtime", {
    "helpers": true,
    "regenerator": false
    }]
]
}

5 重新安装四个库（如果不重新安装这四个库会程序会报错）

yarn add @babel/core
yarn add @babel/plugin-proposal-decorators
yarn add @babel/plugin-transform-runtime
yarn add @babel/runtime

6 运行项目

react-native run-ios