IOS/Swift 暂停跟恢复图层动画

   //mySuperLayer父图层
    CFTimeInterval pausedTime = [self.mySuperLayer timeOffset];
    if (pausedTime > 0)//在暂停后才能使用
    {
        self.mySuperLayer.speed = 1.0;
        self.mySuperLayer.timeOffset = 0.0;
        self.mySuperLayer.beginTime = 0.0;
        CFTimeInterval timeSincePause = [self.mySuperLayer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
        self.mySuperLayer.beginTime = timeSincePause;
    }

    CFTimeInterval pausedTime = [self.mySuperLayer convertTime:CACurrentMediaTime() fromLayer:nil];
    self.mySuperLayer.speed = 0.0;
    self.mySuperLayer.timeOffset = pausedTime;