导出
pip freeze >requirements.txt

安装
pip install -r requirements.txt

//使用bash的改.bash_profile ，使用zsh的用.zshrc
vim .bash_profile 

export PUB_HOSTED_URL=https://pub.flutter-io.cn
export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn

source .bash_profile 

git clone -b beta https://github.com/flutter/flutter.git

It looks like accounts.google.com is having some trouble.
Pub will wait for a while before trying to connect again.
OS Error: Operation timed out, errno = 60, address = accounts.google.com, port = 53165

Jenkins

$ gem sources --add https://gems.ruby-china.com/ --remove https://rubygems.org/
$ gem sources -l
https://gems.ruby-china.com
# 确保只有 gems.ruby-china.com

sudo gem install fastlane -NV

brew tap caskroom/versions
brew cask install java8

1.Yarn是由Facebook、Google、Exponent 和 Tilde 联合推出了一个新的 JS 包管理工具 ,我们写的RN是Facebook开源的,我们当然要用匹配的东西
2.npm很慢,因为是安装完一个package再安装下一个;yarn是并行安装,并且会生成离线库,安装过的库第二次安装都是从缓存的离线库读取,速度很快
3.yarn安装版本统一.存在yarn.lock文件去管理每个库的版本统一
4.yarn能对多注册来源进行处理：所有的依赖包，不管他被不同的库间接关联引用多少次，安装这个包时，只会从一个注册来源去装，要么是 npm 要么是 bower, 防止出现混乱不一致。
5.…………

#xxxx代表库名
#1.安装package.json中已经存在的库
yarn
#2.新增一个库
yarn add xxxx
#3.新增一个库到开发依赖
yarn add xxxx --dev
#4.移除一个库
yarn remove xxxx

yarn add react-navigation

#这是一个手势库
yarn add react-native-gesture-handler
#我也不知道用来干嘛的库,大概是一些屏幕设计吧,这是它的github:https://github.com/browniefed/react-native-screens
yarn add react-native-screens

#react-native-gesture-handler又依赖如下库
yarn add react-art
yarn add react-dom
yarn add react-native-web

react-native link

import UIKit
import ObjectMapper

class BaseModel: Mappable {
    //定义属性
    var name : String? = "wuxing"    
    init() {
//为什么要写这个init,原因很简单,总有些时候你仅仅想初始化一个model,而非通过外部传入数据初始化
    }
    
    required init?(map: Map) {
        //重写ObjectMapper的init
    }
    
    func mapping(map: Map) {
        //转换规则
        name <- map["name"]
    }
 }

import UIKit
import ObjectMapper

class BaseModel: Mappable {
    var man : Bool? = true

    var age : Int? = 21
    init() {
    }
    
    required init?(map: Map) {
        print("BaseModel初始化")
    }
    
    func mapping(map: Map) {
        man <- (map["man"],transformBool)

        age <- (map["age"],transformInt)
    }
    
    
//    转换规则
    
    
    let transformInt = TransformOf<Int, String>(fromJSON: { (value: String?) -> Int? in
        if let value = value {
            return Int(value)!
        }
        return nil
    }, toJSON: { (value: Int?) -> String? in
        // transform value from Int? to String?
        if let value = value {
            return String(value)
        }
        return nil
    })
    
    let transformBool = TransformOf<Bool, String>(fromJSON: { (value: String?) -> Bool? in
        if let value = value {
            return (value as NSString).boolValue
        }
        return false
    }, toJSON: { (value: Bool?) -> String? in
        if let value = value {
            return String(value)
        }
        return "false"
    })
    

}