快速实例化struct
struct VideoModel {
let image: String
let title: String
let source: String
}
实例化:
VideoModel(image: "videoScreenshot01", title: "Introduce 3DS Mario", source: "Youtube - 06:32")
类型转换
类型转换：
as?:返回一个向下转型的类型的可选值
as!:强制转型，并且解包
is:检查能够向下转化成指定类型
as:向上转换成超类
当不确定是否可以转成功时，用as?，确定时，用as!
let cell = tableView.dequeueReusableCell(withIdentifier: reuseIdentifer, for: indexPath) as! VideoCell
其中:!强制解析值，解析前一定确保可选是有值的
函数访问关键字
Public:所有都可以访问
Internal:自己framework访问（默认）
Private:私有的
总的来说，默认就行，不公开就private，写框架的话，就需要public公开接口
重写init
重写类的时候经常提示要添加代码：
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
http://www.jianshu.com/p/66ecd88b4210
学习代码:
VideoCell.swift
import UIKit
struct VideoModel {
let image: String
let title: String
let source: String
}
class VideoCell: UITableViewCell {
let videoImage = UIImageView(frame: CGRect(x: 0, y: 0, width: YHScreenWidth, height: YHScreenHeight/3))
let videoTitle = UILabel(frame: CGRect(x: 0, y: YHScreenHeight/3-50, width: YHScreenWidth, height: 30))
let videoSource = UILabel(frame: CGRect(x: 0, y: YHScreenHeight/3-20, width: YHScreenWidth, height: 20))
/*
Public:所有都可以访问
Internal:自己framework访问（默认）
Private:私有的
总的来说，默认就行，不公开就private，写框架的话，就需要public公开接口
*/
private let videoPlay = UIImageView(frame: CGRect(x: 0, y: 0, width: YHScreenWidth, height: YHScreenHeight/3))
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
setupView()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func setupView() {
videoImage.contentMode = .scaleAspectFill
videoPlay.contentMode = .center
videoPlay.image = UIImage(named: "playBtn")
videoTitle.textColor = .white
videoTitle.font = UIFont(name: "Zapfino", size: 24)
videoTitle.textAlignment = .center
videoSource.textColor = .gray
videoSource.font = UIFont(name: "Avenir Next", size: 14)
videoSource.textAlignment = .center
contentView.addSubview(videoImage)
contentView.addSubview(videoPlay)
contentView.addSubview(videoTitle)
contentView.addSubview(videoSource)
}
func setModel(model: VideoModel) {
videoImage.image = UIImage(named: model.image)
videoTitle.text = model.title
videoSource.text = model.source
}
override func awakeFromNib() {
super.awakeFromNib()
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
ViewController.swift:
import UIKit
import AVKit
import AVFoundation
let YHScreenRect : CGRect = UIScreen.main.bounds
let YHScreenWidth : CGFloat = UIScreen.main.bounds.width
let YHScreenHeight : CGFloat = UIScreen.main.bounds.height
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
let tableView = UITableView(frame: YHScreenRect, style: .plain)
var playViewController: AVPlayerViewController?
var playView: AVPlayer?
let reuseIdentifer = "VideoCell"
let datas = [
VideoModel(image: "videoScreenshot01", title: "Introduce 3DS Mario", source: "Youtube - 06:32"),
VideoModel(image: "videoScreenshot02", title: "Emoji Among Us", source: "Vimeo - 3:34"),
VideoModel(image: "videoScreenshot03", title: "Seals Documentary", source: "Vine - 00:06"),
VideoModel(image: "videoScreenshot04", title: "Adventure Time", source: "Youtube - 02:39"),
VideoModel(image: "videoScreenshot05", title: "Facebook HQ", source: "Facebook - 10:20"),
VideoModel(image: "videoScreenshot06", title: "Lijiang Lugu Lake", source: "Allen - 20:30"),
]
override func viewDidLoad() {
super.viewDidLoad()
setupView()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
playView = nil
playViewController = nil
}
//隐藏状态栏
override var prefersStatusBarHidden: Bool {
return true
}
func setupView() {
tableView.delegate = self
tableView.dataSource = self
tableView.register(VideoCell.self, forCellReuseIdentifier: reuseIdentifer)
view.addSubview(tableView)
}
func playVideo() {
/*
错误处理：
1.throwing，把函数抛出的错误传递给调用此函数的代码
2.do-catch
3.将错误作为可选类型处理
4.断言此错误根本不会发生
*/
let path = Bundle.main.path(forResource: "emoji zone", ofType: "mp4")
/*
guard与if很相似，区别：
1.guard必须强制有else语句
2.只有在guard审查条件成立，guard之后代码才会运行
*/
if path == nil {
print("没有该文件！")
return
}
//由于返回了可选类型，并且通过上方判断，可以确定是有值的，然后强制解包
playView = AVPlayer(url: URL(fileURLWithPath: path!))
playViewController = AVPlayerViewController()
playViewController?.player = playView
self.present(playViewController!, animated: true) {
self.playView?.play()
}
}
//MARK: - delegate
func numberOfSections(in tableView: UITableView) -> Int {
return 2;
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return datas.count
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return YHScreenHeight/3
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
/*
!强制解析值，解析前一定确保可选是有值的
类型转换：
as?:返回一个向下转型的类型的可选值
as!:强制转型，并且解包
is:检查能够向下转化成指定类型
as:向上转换成超类
当不确定是否可以转成功时，用as?，确定时，用as!
*/
let cell = tableView.dequeueReusableCell(withIdentifier: reuseIdentifer, for: indexPath) as! VideoCell
cell.setModel(model: datas[indexPath.row])
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
playVideo()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}