[Swift A]

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)
    }
    
    
}