Swift 3.0初见

Swift 3.0

iOS10 访问权限

//在info.plist文件中添加键值对，输入Privacy 就可以找到各种权限的键 值为描述字符
Privacy - Photo Library Usage Description : 亲，可以打开你的相册吗？
//用到自带地图、钥匙链、后台、HomeKit、VPN等网络配置权限的应用，需要到工程配置的Capabilities中打开对应开关

使用Carthage管理第三方库

touch Cartfile
#list github source
carthage update

Cartfile content

github "Alamofire/Alamofire" ~> 4.0.1
github "SnapKit/SnapKit"  == 3.0.2
github "SwiftyJSON/SwiftyJSON" >= 2.1.2
github "rs/SDWebImage" ~> 3
github "mxcl/PromiseKit" ~> 4.0
github "uacaps/PageMenu"

>= 1.0 for “at least version 1.0”
~> 1.0 for “compatible with version 1.0”
== 1.0 for “exactly version 1.0”

常用第三方库

• Alamofire （类AFN）
• SwiftyJSON （类MJExtension）
• SDWebImage （同）
• SnapKit （类Masorny）
• SwiftLint (代码风格检查器)
• PromiseKit (异步编程框架)
• SVProgressHUD (HUD)

第三方库的基本使用

SVProgressHUD的使用

SVProgressHUD的静态方法

Code	效果
show()	显示无限循环进度条
dismiss()	关闭HUD
showProgress(0.1, status: "正在下载")	显示有进度的HUD
showInfo(withStatus: "请输入密码")	显示信息
showSuccess(withStatus: "下载完成")	显示成功信息
showError(withStatus: "密码错误")	显示错误信息
show(UIImage(named:"icon"), status: "展示图片")	显示自定义图片

Alamofire

• 常用的GET请求

Alamofire.request("https://jsonapi.com").responseJSON { (rs) in
            switch rs.result {
            case .success(let v):
                print(v)
            case .failure(let e):
                print(e)
            }
        }

• 常用的POST请求

let parameters: Parameters = [
            "name": "xiaos",
            "age": 22,]   
Alamofire.request("https://jsonapi.com",method:.post,parameters:parameters).responseJSON { (rs) in
//rs.request?.url == "https://jsonapi.com"
//rs.request?.httpBody == name=xiaos age=22
        }
            
Alamofire.request("https://jsonapi.com",method:.post,parameters:parameters,encoding:URLEncoding.queryString).responseJSON { (rs) in
//rs.request?.url == "https://jsonapi.com?name=xiaos&age=22"
        }

• 完整的GET请求

Alamofire.request("https://jsonapi.com", method: .get, parameters: ["name":"xiaos"], encoding: URLEncoding.methodDependent, headers: ["key1":"value1"]).responseJSON { (rs) in
            print("the request is (rs.request)")//the request is https://jsonapi.com?name=xiaos
            print("the request header is (rs.request?.allHTTPHeaderFields)")//the request header is ["key1": "value1"]
            
            switch rs.result {
            case .success(let v):
                print("this is com req (v)")
            case .failure(let e):
                print("error is (e)")
            }
        }

参数编码的使用

URLEncoding.methodDependent

• 在GET HEAD DELETE中，将参数添加到url后面，拼接成query键值对
• 在POST中，将参数添加到请求体中

URLEncoding.queryString

• 在GET POST HEAD DELETE中，都是将参数添加到url后面，拼接成query键值对

URLEncoding.httpBody

• 在GET HEAD DELETE中无效
• 在POST中，将参数添加到请求体中

默认使用的.methodDependent适合大部分场景

SwiftyJSON的使用

datas.json

{
    "list":[{
            "id":"495450",
            "type_id":"4",
            "title":"你养我长大，我陪你变老……",
            "link":"http://zhangjunliang.baijia.baidu.com/article/649503",
            "summary":"时间都去哪儿了王铮亮 - 听得到的时间当我们还在感叹着时间都去哪儿了时间已经悄悄染白了父母...",
            "addtime":"1476013530",
            "arr":[1,2,3],
            "dict":{"name":"xiao"}
            },
            {
            "id":"495451",
            "type_id":"4",
            "title":"你养我长大，我陪你变老……",
            "link":"http://zhangjunliang.baijia.baidu.com/article/649503",
            "summary":"时间都去哪儿了王铮亮 - 听得到的时间当我们还在感叹着时间都去哪儿了时间已经悄悄染白了父母...",
            "addtime":"1476013530",
            "arr":[4,5,6],
            "dict":{"name":"xiao1"}
            },
            {
            "id":"495452",
            "type_id":"4",
            "title":"你养我长大，我陪你变老……",
            "link":"http://zhangjunliang.baijia.baidu.com/article/649503",
            "summary":"时间都去哪儿了王铮亮 - 听得到的时间当我们还在感叹着时间都去哪儿了时间已经悄悄染白了父母...",
            "addtime":"1476013530",
            "arr":[7,8,9],
            "dict":{"name":"xiao2"}
            }
            ]
}

model

import Foundation
import SwiftyJSON

class NewsModel {
    var id:String?
    var type_id:String?
    var title:String?
    var link:String?
    var summary:String?
    var addtime:String?
    var arr:[Any]?
    var dict:[String:Any]?
    
    init(_ json:JSON) {
        self.id = json["id"].string
        self.type_id = json["type_id"].string
        self.link = json["title"].string
        self.summary = json["link"].string
        self.addtime = json["addtime"].string
        self.arr = json["arr"].array
        self.dict = json["dict"].dictionary
    }
}

转换json数据为对象

let filePath = Bundle.main.path(forResource: "datas", ofType: "json")
if let jsonPath = filePath {
  do {
      let data = try Data(contentsOf: URL(fileURLWithPath: jsonPath))
      let dict = try JSONSerialization.jsonObject(with: data as Data, options: JSONSerialization.ReadingOptions.mutableLeaves)
      if let list = JSON(dict)["list"].array {
          //let newsModels:[NewsModel] = list.map(v in return NewsModel(v))
          let newsModels:[NewsModel] = list.map({NewsModel($0)})
          print(newsModels)//此处已经将json中的list数组转换为newsModel对象数组
      }
  }
  catch{
      print(error)
  }
}

转换json的data

let jsonStr = "{"name":"xiao"}"
if let jsonData = jsonStr.data(using: .utf8, allowLossyConversion: false) {
  let json = JSON(data: jsonData)
  print(json["name"].string)//xiao?
}

PromiseKit与Alamofire的配合使用

//model
class Person {
    var name:String?    
    init(_ json:JSON) {
        self.name = json["name"].string
    }
}

//handle data
//json1.json {"name":"xiaos1"}
firstly {
  Alamofire.request("https://www.xsdota.com/json1.json").responseJSON()
}.then(on:DispatchQueue.global()) { (json) -> Promise<Person> in
  let json = JSON(json)
  return Promise(value:Person(json))
}.then { (person) -> Void in
  print("person name is (person.name)")
}.catch { (e) in
  print(e)
}

func login(username:String,pwd:String) -> Promise<Person> {
    let q = DispatchQueue.global()
    UIApplication.shared.isNetworkActivityIndicatorVisible = true
       
    let params = ["username":username,"pwd":pwd]
       
    return
      firstly {
          Alamofire.request("https://www.xsdota.com/login.json",parameters:params).responseJSON()
      }
      .then(on: q) { json in
          Person(JSON(json))
      }
      .always {
          UIApplication.shared.isNetworkActivityIndicatorVisible = false
      }
}

firstly {
  login(username: "xiaos", pwd: "123456")
}
.then { (person) -> Void in
  print(person.name)
}
.catch { (e) in
  switch e {
      case Alamofire.AFError.responseSerializationFailed:
          self.bn_showInfo(msg: "json解析失败")
      default:break
  }
}

//when 多个异步任务全部处理完成后
let oneTask = Alamofire.request("https://www.xsdota.com/json3.json").responseJSON()
let twoTask = Alamofire.request("https://www.xsdota.com/json2.json").responseJSON()
   
when(fulfilled: [oneTask,twoTask])
.then { (rs) -> Void in
  for result in rs {
      print(result)
  }
}.catch { (e) in
  print(e)
}

//race 龟兔赛跑 谁先完成获得谁的结果
race(oneTask,twoTask).then { (rs) -> Void in
  print("龟兔赛跑 冠军是 (JSON(rs)["name"])")
}.catch { (e) in
  print(e)
}

Promise与UIKit的配合

UIAlertController

let alert = PMKAlertController.init(title: "this is title", message: "this is msg", preferredStyle: .alert)
let one = alert.addActionWithTitle(title: "one")
let two = alert.addActionWithTitle(title: "two")
promise(alert)
  .then { (action) -> Promise<Int> in
      switch action {
          case one:
              return Promise(value:10)
          case two:
              return Promise(value:20)
          default: throw BNError.msg
      }
  }
  .then {num ->Void in
      print("num is (num)")
  }.catch { (e) in
      print(e)
}

现代的Swift

代码风格指南

• 可读性第一
• 文档注释第二
• 枚举类型以大写开头的驼峰形式，函数和变量以小写开头的驼峰形式
• 使用类型接口

集合

集合

for-if简写

let datas = [1,2,3,4,5]
for i in datas {
    if i == 2{
        print(i) //2
    }
}

for i in datas where i == 2 {
    print(i) //2
}

Map方法

//获得斐波那契数列的平方
//常规写法
let fibs = [1,1,2,3,5,8]
var squared:[Int] = []
for fib in fibs {
    squared.append(fib*fib)
}
//map写法
let squared = fibs.map{fib in fib*fib}
//可以用map方法来完成的操作，一般就是新建一个数组容器，然后遍历数据源，操作后把结果塞进容器中。诸如此类所有操作都可以用map代替

//map方法的实现
extension Array {
    func map<U>(transform:Element->U) -> [U]{
        var result:[U] = []
        result.reserveCapacity(self.count)
        for x in self {
            result.append(transform(x))
        }
        return result
    }
}
//Element是数组元素的占位符

Filter方法

fibs.filter{num in num%2 == 0}//获得fibs数组中能被2整除的元素

//filter方法发实现
extension Array{
    func filter (f:Element->Boll) -> [Element] {
        var result:[Element] = []
        for item in self where f(item) {
            result.append(item)
        }
        return result
    }    
}

Reduce方法

var sum = 0
for num in fibs {
    sum = sum + num
}

fibs.reduce(0){sum,num in sum+num}
//实现
extension Array {
    func reduce<U>(var initial:U,f:(U,Element)->U) ->U {
        for item in self {
            initial = f(initial,item)
        }
        return initial
    }
}

//可以理解函数式。不推荐使用，时间复杂度高
//使用reduce模拟map方法
extension Array {
    func map2<U>(transform:Element->U) -> [U]{
        return reduce([],f:{item1,item2 in item1 + [transform(item2)]})
    }
}
//模拟filter方法
extension Array {
    func filter2(f:Element->Bool) -> [Element] {
        return reduce([],{item1,item2 in f(item2)?item+[item2]:item1})
    }
}

flatMap方法

//flatMap铺平的map方法


let suits = ["1", "2", "3", "4"]
let ranks = ["J", "Q", "K", "A"]

let allCombinations = suits.flatMap { suit in
    ranks.map{ rank in
        (suit, rank)
    }
}