网络规范开发简单练习－swift－NSURLConnection

虽然NSURLConnection已经很少使用，可是并不能说明它不重要，对于一个初学者来说，要想学好网络，必须从最基础的地方入手，基础牢了，在以后的学习中才能事半功倍。根基不稳，再怎么小心翼翼也抵达不到云层。

所用接口

//限免
"http://iappfree.candou.com:8080/free/applications/limited?currency=rmb&page=1”
//降价
"http://iappfree.candou.com:8080/free/applications/sales?currency=rmb&page=1”
//免费
"http://iappfree.candou.com:8080/free/applications/free?currency=rmb&page=1”

www.bejson.com 解析

效果

<img src="/Users/qianfeng/Desktop/屏幕快照 2016-08-25 下午6.37.00.png" width = "120" height = "200" />
<img src="/Users/qianfeng/Desktop/屏幕快照 2016-08-25 下午6.37.10.png" width = "120" height = "200" />
<img src="/Users/qianfeng/Desktop/屏幕快照 2016-08-25 下午6.37.20.png " width = "120" height = "200" />

删除Mainboard，ViewController，Info.plist中的Main函数入口,导入第三方库MJRefresh(下拉刷新),SDWebImage并设置桥接。

• 右键项目->NewFile->ios(Source)->Header File->Save As:(输入文件名字，例如：bridgingHeader)->Create
• 打开bridgingHeader.h导入第三方库
  (#import "UIImageView+WebCache.h"
  (#import "MJRefresh.h"
• 桥接 ->点一下项目名->点一下左边PROJECT下的文件名 ->Build Settings ->选择All ->输入bridge搜索->Objectives-C Bridging Header->双击右侧空白区域输入->文件夹的名字/bridgingHeader.h

桥接文件时，如果.h文件建在根项目下，直接输入文件名字即可，如果在文件夹内，则需要加入文件夹的名字，在这里我们把桥接文件建立在了文件夹内

1.新建一个MytabBarController继承自UITabBarController

2.打开AppDelegate.swift文件，修改里面的第一个函数application

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        window = UIWindow.init(frame: UIScreen.mainScreen().bounds)
        window?.rootViewController = MyTabBarController()
        window?.backgroundColor = UIColor.whiteColor()
        window?.makeKeyAndVisible()
        return true
    }

3.

• 新建一个BaseViewController作为所有控制器的基类，用来统一修改界面风格,现在只插入一行代码作为示范

self.view.backgroundColor = UIColor.grayColor()

* 新建ListViewController继承自BaseViewController
* 新建LimitViewController,FreeViewController,SaleViewController分别继承自ListViewController
###4.新建一个TabBar.plist文件，用来存放MyTabBarController里的控制器内容，在文章底部自行下载源代码进行查看tabBar.plist文件，此处不再上图
###5.打开MytabBarController文件进行编辑

override func viewDidLoad() {
super.viewDidLoad()

    //工程名
    let proName = NSBundle.mainBundle().infoDictionary!["CFBundleExecutable"] as! String
    
    //拿到plist文件路径
    let path = NSBundle.mainBundle().pathForResource("TabBar.plist", ofType: nil)!
    
    //将plist文件数据读到数组里
    let plistArr = NSArray.init(contentsOfFile: path) as! [[String : String]]
    for dic in plistArr {
        
        //拿到代表类名的字符串
        let name = proName + "." + dic["name"]!
        
        // self      Type     dynamicType
        //将字符串转成类
        let vcClass = NSClassFromString(name) as! UIViewController.Type
        
        //构造页面对象
        let vc = vcClass.init()
        
        //导航
        let nc = UINavigationController.init(rootViewController: vc)
        vc.navigationItem.title = dic["title"]
        
        //显示在tabBar上的专用按钮
        nc.tabBarItem = UITabBarItem.init(title: dic["title"], image: UIImage.init(named: dic["icon"]!), tag: 0)
        
        //将页面／导航添加到tabBarController里面
        self.addChildViewController(nc)
    }
}

    

##注意：以上只是用纯代码规范化搭建了一个tabController的界面，仅作参考，读者也可以自行拖控件搭建
###6.新建AppModel继承自NSObject用来存放数据模型

class AppModel: NSObject {

var applicationId: String?
var iconUrl: String?
var name: String?
var starCurrent: String?
var lastPrice: String?
var categoryName: String?
var favorites: String?
var shares: String?
var downloads: String?
var expireDatetime: String?
var currentPrice: String?


static func modelWith(dic: [String: AnyObject]) -> AppModel {
    let model = AppModel()
    model.setValuesForKeysWithDictionary(dic)
    return model
}
//如果输入了未定义的属性，则调用该方法
override func setValue(value: AnyObject?, forUndefinedKey key: String) {
    print("您输入了未定义属性的Key：\(key)")
}

}

###7.新建AppCell继承自UITableViewCell并勾选xib文件,界面自行搭建，此处不再演示,cell重用标识符"qqq"，需要注意的是降价页面又一个黑色的线，可以用view，背景设置为黑色（但在cell点击时，cell内的所有控件的背景色都将失去效果）

![](/Users/qianfeng/Desktop/屏幕快照 2016-08-24 下午7.50.16.png)

###8.编辑ListViewContoller文件，ListViewController放了所有控制器界面的相同部分（请先编写第9步）

class ListViewController: BaseViewController {

let limit_url = "http://iappfree.candou.com:8080/free/applications/limited?currency=rmb&page=%d"
let sale_url = "http://iappfree.candou.com:8080/free/applications/sales?currency=rmb&page=%d"
let free_url = "http://iappfree.candou.com:8080/free/applications/free?currency=rmb&page=%d"

let tableView = UITableView()
var dataArr = [AppModel]()

var urlStr: String?
//记录触底加载的页数
var page = 2
    
override func viewDidLoad() {
    super.viewDidLoad()
    tableView.frame = self.view.frame
    tableView.delegate = self
    tableView.dataSource = self
    self.view.addSubview(tableView)
    tableView.separatorColor = UIColor.redColor()
    tableView.rowHeight = 100
    tableView.registerNib(UINib.init(nibName: "AppCell", bundle: nil), forCellReuseIdentifier: "qqq")
    //闭包会捕获内部使用的实例（强引用）
    //为了防止循环引用，闭包内部通常都用弱引用
    weak var weakSelf = self
    //下拉刷新的控件
    tableView.mj_header = MJRefreshNormalHeader.init(refreshingBlock: { 
        let url = String.init(format: weakSelf!.urlStr!, 1)
        let mc = MyConnection.init(urlStr: url, target: weakSelf!, action: #selector(weakSelf!.connectionFinish(_:)),tag: 1)
        mc.start()
    })
    
    //上拉刷新控件
    tableView.mj_footer = MJRefreshAutoNormalFooter.init(refreshingBlock: { 
        let url = String.init(format: weakSelf!.urlStr!, weakSelf!.page)
        let mc = MyConnection.init(urlStr: url, target: weakSelf!, action: #selector(weakSelf!.connectionFinish(_:)),tag: 2)
        mc.start()
    })
    
    //直接进入下拉刷新状态
    tableView.mj_header.beginRefreshing()
    if let data = self.readLocal() {
        self.parseData(data)
    }
}

func connectionFinish(mc:MyConnection) -> Void {
    if mc.isFinish {
    //触底加载之后会有许多内容，然后上拉刷新恢复
        if mc.tag == 1 {
            dataArr.removeAll()
            page = 2
            self.writeTolocalWith(mc.downloadData)
        } else {
            page += 1
        }
        self.parseData(mc.downloadData)
        tableView.reloadData()
    } else {
        print("\(self)网络请求失败")
    }
    //关闭加载状态
    tableView.mj_header.endRefreshing()
    tableView.mj_footer.endRefreshing()
}

func parseData(data:NSData) -> Void {
    //json
    let dataDic = try! NSJSONSerialization.JSONObjectWithData(data, options: .AllowFragments) as! NSDictionary
    let appArr = dataDic["applications"] as! [[String: AnyObject]]
    
    //字典转模型
    for appDic in appArr {
        dataArr.append(AppModel.modelWith(appDic))
    }
    
}

}

//MARJK: 缓存
extension ListViewController {
//往本地存数据
func writeTolocalWith(data: NSData) {
//类名转成字符串
let name = NSStringFromClass(self.dynamicType)
//拼接完整的沙盒路径
let path = String.init(format: "%@/Documents/%@.txt", NSHomeDirectory(),name)
//将数据写入文件
data.writeToFile(path, atomically: true)

}

//从本地读区数据
func readLocal() -> NSData? {
    let name = NSStringFromClass(self.dynamicType)
    let path = String.init(format: "%@/Documents/%@.txt", NSHomeDirectory(),name)
    return NSData.init(contentsOfFile: path)
}

}

extension ListViewController: UITableViewDelegate, UITableViewDataSource {
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return dataArr.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("qqq", forIndexPath: indexPath) as! AppCell
cell.customWithModel(dataArr[indexPath.row])
return cell
}
}

###9.新建MyConnection继承自NSObject

class MyConnection: NSObject {
//MARK:属性
//记录网址
var urlStr: String?
//记录下载的数据
let downloadData = NSMutableData()

//记录一个对象
var target: AnyObject?
//记录一个方法
var action: Selector?

//记录下载的状态
var isFinish: Bool = false

//标记
var tag: Int?

//记录执行网络连接的对象
var connection: NSURLConnection?

//MARK:方法
init(urlStr: String, target: AnyObject, action: Selector, tag: Int = 0) {
self.urlStr = urlStr
self.target = target
self.action = action
self.tag = tag
}

//启动
func start() -> Void {
    let url = NSURL.init(string: urlStr!)!
    let request = NSURLRequest.init(URL: url)
    UIApplication.sharedApplication().networkActivityIndicatorVisible = true
    connection = NSURLConnection.init(request: request, delegate: self)
}

func stop() -> Void {
    connection?.cancel()
}

deinit {
    UIApplication.sharedApplication().networkActivityIndicatorVisible = false
}

}

extension MyConnection: NSURLConnectionDataDelegate {
func connection(connection: NSURLConnection, didReceiveResponse response: NSURLResponse) {
self.downloadData.length = 0
}
func connection(connection: NSURLConnection, didReceiveData data: NSData) {
self.downloadData.appendData(data)
}
func connectionDidFinishLoading(connection: NSURLConnection) {
self.isFinish = true
self.target!.performSelector(action!, withObject: self)
}
func connection(connection: NSURLConnection, didFailWithError error: NSError) {
self.isFinish = false
self.target!.performSelector(action!, withObject: self)
}
}

###10.编辑LimitViewController

class LimitViewController: ListViewController {

override func viewDidLoad() {
    super.viewDidLoad()

    self.urlStr = self.limit_url
    
    
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = super.tableView(tableView, cellForRowAtIndexPath: indexPath) as! AppCell
    let model = dataArr[indexPath.row]
    
    
    cell.subLabel.text = self.stringFrom(model.expireDatetime!)
    
    return cell
}

func stringFrom(dataStr:String) -> String {
    //时间戳(将时间和字符串进行转化)
    let dateFormat = NSDateFormatter()
    //设置转化格式（大MM，小dd，ss后面的 .0可要可不要）
    dateFormat.dateFormat = "yyyy-MM-dd HH:mm:ss.0"
    let date = dateFormat.dateFromString(dataStr)!
    //计算时间差
    let time = Int(date.timeIntervalSinceNow)
    
    return String.init(format: "剩余：%02d:%02d:%02d", time / 3600, time % 3600 / 60, time % 60)
}

}

###11.编辑FreeViewController

class FreeViewController: ListViewController {

override func viewDidLoad() {
    super.viewDidLoad()

    self.urlStr = self.free_url
    
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = super.tableView(tableView, cellForRowAtIndexPath: indexPath) as! AppCell
    cell.subLabel.text = "我爱中国"
    return cell
}

}

###12.编辑SaleViewController

class SaleViewController: ListViewController {

override func viewDidLoad() {
    super.viewDidLoad()

    self.urlStr = self.sale_url
}

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = super.tableView(tableView, cellForRowAtIndexPath: indexPath) as! AppCell
    let model = dataArr[indexPath.row]
    cell.subLabel.text = String.init(format: "现价：¥%0.1f", Float(model.currentPrice!)!)
    return cell
}

}

###补充：在Info.plist文件中加入http链接的请求，读者自己比较.plist文件有什么不同，缺少的地方自己点击加入
[点这里下载源代码](/Users/qianfeng/Desktop/LoveFree副本.zip)