CABasicAnimation动画完成后，界面闪烁

      CABasicAnimation执行动画完成后，创建的layer又回到的之前的位置，并且闪烁一下，需要创建的动画添加一下两行代码：

                    CABasicAnimation *animation =  [CABasicAnimation animationWithKeyPath:@"transform.translation.x"];

                    animation.removedOnCompletion = NO;

                    animation.fillMode = kCAFillModeForwards