加载本地沙盒音效

点击按钮会有音效、进入某个vc会播放背景音乐等，都是加载本地沙盒的音效

0.本地沙盒中添加音效：

1.加载音效的方法

//加载本地沙盒音效
func loadSound(_ soundFileName: String) -> SystemSoundID {
    let path = Bundle.main.path(forResource: soundFileName, ofType: nil)
    let url = URL(fileURLWithPath: path!)
    var soundId: SystemSoundID = 0
    AudioServicesCreateSystemSoundID(url as CFURL, &soundId)
    return soundId
}

2.音效的使用：

//定义音效属性
var btnClickSoundId: SystemSoundID = 0

//给音效赋值
btnClickSoundId = loadSound("ding3.mp3")

//调起音效
AudioServicesPlaySystemSound(self.btnClickSoundId)