Xcode Swift-无法解析的标识符错误

Question

Please help me to edit my code. I cant seem to fix this error.

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

You have to move the two lines regarding the avPlayer and avPlayerViewControler inside the if since the constant movieUrl is only available inside that scope - it only exists inside the scope it was defined in, it does not exist outside of the if -block!

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
    }
}