if let buttonBeep = self.setupAudioPlayerWithFile("ButtonTap", type: "wav") {
self.buttonBeep = buttonBeep
}
if let secondBeep = self.setupAudioPlayerWithFile("SecondBeep", type: "wav") {
self.secondBeep = secondBeep
}
if let backgroundMusic = self.setupAudioPlayerWithFile("HallOfTheMountainKing", type: "mp3") {
self.backgroundMusic = backgroundMusic
}
这样写就报错了initializer for conditional binding must have optional type not AVAudioPlayer。
最后将代码改为：
if let buttonBeep: AnyObject = self.setupAudioPlayerWithFile("ButtonTap", type: "wav") {
self.buttonBeep = buttonBeep as? AVAudioPlayer
}
if let secondBeep:AnyObject = self.setupAudioPlayerWithFile("SecondBeep", type: "wav") {
self.secondBeep = secondBeep as? AVAudioPlayer
}
if let backgroundMusic:AnyObject = self.setupAudioPlayerWithFile("HallOfTheMountainKing", type: "mp3") {
self.backgroundMusic = backgroundMusic as? AVAudioPlayer
}
就没有问题了。