[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)
}

}