ios两个子视图同一时间进入和离开动画(2)

        [UIView animateWithDuration:2 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{

            targetSubview.frame = CGRectMake(0, -50, targetSubview.frame.size.width, targetSubview.frame.size.height);

            targetSubview.alpha=1.0;

            targetSubview.frame = CGRectMake(0, 0, targetSubview.frame.size.width, targetSubview.frame.size.height);

            sourceSubview.frame = CGRectMake(0, sourceSubview.frame.size.height, sourceSubview.frame.size.width, sourceSubview.frame.size.height);

            sourceSubview.alpha=0.0;

        } completion:^(BOOL finished) {

            [self printSubviews];

             sourceSubview.hidden = YES;

             sourceSubview.alpha=1.0;

        }];

最后，使用这个简单点的方法实现了需求。

在动画结束后，将sourceSubview设置为隐藏。

UIView中可以设置动画效果的属性：
frame
bounds
center
transform
alpha
backgroundColor
contentStretch