[Swift A] - 实战-豆瓣电台总结

最近在学Swift，也是刚刚开始。这里对自己最近所学做个简单的总结：视频和代码都在下面

http://pan.baidu.com/s/1sjHd5qX

1.String和NSString的不同

 Swift的String类型是值类型。如果你创建了一个新的字符串值，那么当其进行常量、变量赋值操作或在函数/方法中传递时，会进行值拷贝。

 在不同的情况下，都会对已有字符串值创建新的副本，并对该新副本进行传递或赋值。

 这和OC中的NSString不同，当您在OC创建了一个NSString实例，并将其传递给一个函数/方法,或者赋给一个变量，您永远都是传递或赋值同一个NSString实例的一个引用。

 除非您特别要求其进行值拷贝，否则字符串不会进行赋值新副本操作。

2.异步获取数据

  NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler:{(response:NSURLResponse!, data:NSData!, error:NSError!)->Void in
             var jsonResult:NSDictionary = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
             //why just miss an excalmatory mark, the code isn't compile
             //self.delegate?.didRecieveResults(jsonResult)
         })

3.UI焦点的易操作

在UI的界面种可以直接在View上点击鼠标右键，并拖入相应的Controller的代码中，且生成@IBOutlet和@IBAction。代码都不用手写了，很方便。

4.视图之间的跳转，传参，回跳

 //页面跳转时，将数据传过去
     override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
         var channelC:ChannelController = segue.destinationViewController as ChannelController
         channelC.delegate = self// What TODO
         channelC.channelData = self.channelData
     }

 //点击事件
     func tableView(tableView:UITableView!, didSelectRowAtIndexPath indexPath:NSIndexPath!) {
         //what is do this
         var rowData:NSDictionary = self.channelData[indexPath.row] as NSDictionary
         let channelId:AnyObject = rowData["channel_id"] as AnyObject
         let channel:String = "channel=\(channelId)"
         delegate?.onChangeChannel(channel)
         self.dismissViewControllerAnimated(true, completion: nil)
     }

5.MP3在线播放

 //定义一个播放器
     var audioPlayer:MPMoviePlayerController = MPMoviePlayerController()

 //设置音乐
     func onSetAudio(url:String) {
         timer?.invalidate()
         timeLabel.text = "00:00"

         self.audioPlayer.stop()
         self.audioPlayer.contentURL = NSURL(string:url)
         self.audioPlayer.play()
         timer = NSTimer.scheduledTimerWithTimeInterval(0.4 , target : self, selector : "onUpdate", userInfo: nil, repeats :true)

         playBtn.removeGestureRecognizer(tap)
         logo.addGestureRecognizer(tap)
         playBtn.hidden = true
     }

6.TableView列表Item的出现动画

 func tableView(tableView: UITableView!, willDisplayCell cell: UITableViewCell!, forRowAtIndexPath indexPath: NSIndexPath!) {
         cell.layer.transform = CATransform3DMakeScale(0.1, 0.1, 1)
         UIView.animateWithDuration(0.25, animations:{cell.layer.transform=CATransform3DMakeScale(1, 1, 1)})
     }

7.UI控件汇总

 UIViewController
 UITableViewDataSource
 UITableViewDelegate
 UIImageView
 UILabel
 UIButton
 UIProgressView
 UITableView
 UITapGestureRecognizer
 UIImage
 MediaPlayer

8.最后把代码贴出来以供学习

 import UIKit
 import MediaPlayer
 import QuartzCore

 class ViewController: UIViewController ,UITableViewDataSource, UITableViewDelegate, HttpProtocol, ChannelProtocol{

     @IBOutlet var logo: UIImageView
     @IBOutlet var timeLabel: UILabel
     @IBOutlet var buttonNext: UIButton
     @IBOutlet var progressBar: UIProgressView
     @IBOutlet var itemLayout: UITableView
     //开始点击事件
     @IBOutlet var tap: UITapGestureRecognizer = nil //这里必须为空，否则报错

     @IBOutlet var playBtn: UIImageView

     //to cache the picture of songs
     var imageCache = Dictionary<String, UIImage>()

     var eHttp:HttpController = HttpController()
     //主界面
     var tableData:NSArray =  NSArray()
     //频道列表
     var channelData:NSArray = NSArray()
     //定义一个播放器
     var audioPlayer:MPMoviePlayerController = MPMoviePlayerController()

     var timer:NSTimer?

     @IBAction func onTap(sender: UITapGestureRecognizer) {
         if sender.view == playBtn {
             playBtn.hidden = true
             audioPlayer.play()
             playBtn.removeGestureRecognizer(tap)
             logo.addGestureRecognizer(tap)
         } else if sender.view == logo{
             playBtn.hidden = false
             audioPlayer.pause()
             playBtn.addGestureRecognizer(tap)
             logo.removeGestureRecognizer(tap)
         }
     }

     override func viewDidLoad() {
         super.viewDidLoad()
         //视图加载完之后，获取数据
         eHttp.delegate = self
         eHttp.onSearch("http://www.douban.com/j/app/radio/channels")
         eHttp.onSearch("http://douban.fm/j/mine/playlist?channel=0")
         progressBar.progress = 0.0
         logo.addGestureRecognizer(tap)

     }

     override func didReceiveMemoryWarning() {
         super.didReceiveMemoryWarning()
         // Dispose of any resources that can be recreated.
     }

     func tableView(tableView: UITableView!, willDisplayCell cell: UITableViewCell!, forRowAtIndexPath indexPath: NSIndexPath!) {
         cell.layer.transform = CATransform3DMakeScale(0.1, 0.1, 1)
         UIView.animateWithDuration(0.25, animations:{cell.layer.transform=CATransform3DMakeScale(1, 1, 1)})
     }

     //TODO
     override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
         var channelC:ChannelController = segue.destinationViewController as ChannelController
         channelC.delegate = self// What TODO
         channelC.channelData = self.channelData
     }

     func onChangeChannel(channelId:String) {
         let url:String = "http://douban.fm/j/mine/playlist?\(channelId)"
         eHttp.onSearch(url)
     }

     func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
         return tableData.count
     }
     //列表展示
     func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
         let cell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "songs")
         let rowData:NSDictionary = self.tableData[indexPath.row] as NSDictionary
         cell.text = rowData["title"] as String
         cell.detailTextLabel.text = rowData["artist"] as String
         //默认图片
         cell.image = UIImage(named:"detail.jpg")
         //缩略图
         let url = rowData["picture"] as String
         let image = self.imageCache[url] as? UIImage
         if !image?{// why do this
             let imgURL:NSURL = NSURL(string:url)
             let request:NSURLRequest = NSURLRequest(URL:imgURL)
             NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler: {(response:NSURLResponse!, data:NSData!, error:NSError!) -> Void in
                 let img = UIImage(data:data)
                 cell.image = img
                 //缓存图片
                 self.imageCache[url] = img
                 })
         } else {// if no this else, the item will be default image
             cell.image = image
         }

         return cell
     }

     func didRecieveResults(results:NSDictionary) {
         //println(results);
         if(results["channels"]) {
             self.channelData = results["channels"] as NSArray
             //self.itemLayout.reloadData()
         } else if(results["song"]) {
             self.tableData = results["song"] as NSArray
             self.itemLayout.reloadData()

             let firDict:NSDictionary = self.tableData[0] as NSDictionary
             let audioUrl:String = firDict["url"] as String
             onSetAudio(audioUrl)
             let imgUrl:String = firDict["picture"] as String
             onSetImage(imgUrl)
         }

     }

     func tableView(tableView:UITableView!, didSelectRowAtIndexPath indexPath:NSIndexPath!) {
         let rowData:NSDictionary = self.tableData[indexPath.row] as NSDictionary
         let audioUrl:String = rowData["url"] as String
         onSetAudio(audioUrl)
         let imgUrl:String = rowData["picture"] as String
         onSetImage(imgUrl)
     }

     //设置音乐
     func onSetAudio(url:String) {
         timer?.invalidate()
         timeLabel.text = "00:00"

         self.audioPlayer.stop()
         self.audioPlayer.contentURL = NSURL(string:url)
         self.audioPlayer.play()
         timer = NSTimer.scheduledTimerWithTimeInterval(0.4 , target : self, selector : "onUpdate", userInfo: nil, repeats :true)

         playBtn.removeGestureRecognizer(tap)
         logo.addGestureRecognizer(tap)
         playBtn.hidden = true
     }

     func onUpdate() {
         let c = audioPlayer.currentPlaybackTime
         if c > 0.0 {
             let t = audioPlayer.duration
             let p:CFloat=CFloat(c/t)

             progressBar.setProgress(p, animated: true)

             let allSecond:Int = Int(c)
             let s:Int = allSecond%60
             let m:Int = Int(allSecond/60)
             var time:String = ""
             if(m < 10) {
                 time = "0\(m)"
             } else {
                 time = "\(m)"
             }
             if(s < 10) {
                 time += ":0\(s)"
             } else {
                 time += ":\(s)"
             }
             timeLabel.text = time

         }
     }

     //设置图片
     func onSetImage(url:String) {
         let image = self.imageCache[url] as? UIImage
         if !image?{// why do this
             let imgURL:NSURL = NSURL(string:url)
             let request:NSURLRequest = NSURLRequest(URL:imgURL)
             NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler: {(response:NSURLResponse!, data:NSData!, error:NSError!) -> Void in
                 let img = UIImage(data:data)
                 self.logo.image = img
                 //缓存图片
                 self.imageCache[url] = img
                 })
         } else {// if no this else, the item will be default image
             self.logo.image = image
         }

     }

 }

 import UIKit

 protocol HttpProtocol {
     func didRecieveResults(results:NSDictionary)
 }

 class HttpController : NSObject {

     var delegate:HttpProtocol?

     func onSearch(url:String) {
         var nsUrl:NSURL = NSURL(string:url)
         var request:NSURLRequest = NSURLRequest(URL:nsUrl)
         //1.Closure Expression Syntax
         //2.异步获取数据

         NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler:{(response:NSURLResponse!, data:NSData!, error:NSError!)->Void in
             var jsonResult:NSDictionary = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
             //why just miss an excalmatory mark, the code isn't compile
             //self.delegate?.didRecieveResults(jsonResult)
         })
     }
 }

 import UIKit
 import QuartzCore

 protocol ChannelProtocol {
     func onChangeChannel(channelId:String)// why is String, is not NSString
 }

 class ChannelController: UIViewController, UITableViewDataSource, UITableViewDelegate {

     @IBOutlet var listLayout: UITableView

     var channelData:NSArray = NSArray()
     var delegate:ChannelProtocol?

     override func viewDidLoad() {
         super.viewDidLoad()
         // Do any additional setup after loading the view, typically from a nib.
     }

     override func didReceiveMemoryWarning() {
         super.didReceiveMemoryWarning()
         // Dispose of any resources that can be recreated.
     }

    func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
         return 10
     }

     func tableView(tableView: UITableView!, willDisplayCell cell: UITableViewCell!, forRowAtIndexPath indexPath: NSIndexPath!) {
         cell.layer.transform = CATransform3DMakeScale(0.1, 0.1, 1)
         UIView.animateWithDuration(0.25, animations:{cell.layer.transform=CATransform3DMakeScale(1, 1, 1)})
     }

     func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
         let cell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "channel")
         let rowData:NSDictionary = self.channelData[indexPath.row] as NSDictionary
         cell.text = rowData["name"] as String
         return cell
     }

     func tableView(tableView:UITableView!, didSelectRowAtIndexPath indexPath:NSIndexPath!) {
         //what is do this
         var rowData:NSDictionary = self.channelData[indexPath.row] as NSDictionary
         let channelId:AnyObject = rowData["channel_id"] as AnyObject
         let channel:String = "channel=\(channelId)"
         delegate?.onChangeChannel(channel)
         self.dismissViewControllerAnimated(true, completion: nil)
     }

 }