Xcode swift - 未解决的标识符错误

Question

请帮我编辑我的代码。我似乎无法解决这个错误。

import UIKit 
import AVKit 
import AVFoundation 
import MediaPlayer 

class ViewController: UIViewController { 

    let avPlayerViewControler = AVPlayerViewController() 
    var avPlayer:AVPlayer? 
    var videoNumber:Int! 
    var url:String! 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     let urlpathString:String? = NSBundle.mainBundle().pathForResource("url", ofType: "mp4") 

     if let urlPath = urlpathString { 

      switch videoNumber { 
      case 1 : url="20" 
      case 2 : url="10" 
      default : break 
      } 
      let movieUrl = NSURL(fileURLWithPath: urlPath) 

     } 
     self.avPlayer = AVPlayer(URL: movieUrl) 
     self.avPlayerViewControler.player = self.avPlayer 

    } 

    @IBAction func Cool(sender: UIButton) { 
     videoNumber=1 
    } 
} 

Answer 1

你有关于avPlayer和avPlayerViewControler的if内的两个线移动，因为不断movieUrl仅仅是范围内可用的 - 它只存在它是在限定的范围内，它不存在在if之外 - 块！

override func viewDidLoad() { 
    super.viewDidLoad() 

    let urlpathString:String? = NSBundle.mainBundle().pathForResource("url", ofType: "mp4") 

    if let urlPath = urlpathString { 

     switch videoNumber { 
      case 1 : url="20" 
      case 2 : url="10" 
      default : break 
     } 
     let movieUrl = NSURL(fileURLWithPath: urlPath) 
     self.avPlayer = AVPlayer(URL: movieUrl) 
     self.avPlayerViewControler.player = self.avPlayer 
    } 
}