Swift异常 try 使用方式

do{
        let backgroundMusicPlayer = try AVAudioPlayer(contentsOf: url)
        // .....
    }catch{
        print(error)
    }

try?方式

guard let backgroundMusicPlayer = try? AVAudioPlayer(contentsOf: url) else {

        return
    }

try!方式

let backgroundMusicPlayer = try! AVAudioPlayer(contentsOf: url)

try!方式 一旦有异常，程序直接奔溃