[bug]:CYLTabBar frame可能在某些系统版本下设置错误

[dbcrystal]

Base Info for this issue

1. Version：Latest Version as here
2. Language of App ：Objective-C
3. iOS System Version：iOS12
4. Prototype（是否是真机）：YES
5. Issue Type：Bug、Q-A

1. How to reproduce the problem.

设备：iOS 12，CYL_IS_IPHONE_X为true（刘海屏） 逻辑：自定义页面transition动画，设置from页面需要在to页面推出时进行缩放 现象：CYLTabBar的originY被拉高

原因：在新页面Push出来时，-[CYLTabBarController viewWillLayoutSubviews]被调用，若CYL_IS_IPHONE_X为true则重设self.tabbar的frame。此时获取的self.view.frame.size.height为缩放后的高度尺寸。

这个frame在iOS 12及以上设备都会被错误设置，但在高版本系统中，在-[CYLTabBarController viewWillLayoutSubviews]调用后，系统会再次调用-[UITabBarController _layoutContainerView]，这个函数中会重新设置一次tabBar的frame，导致问题在高版本会被修复。-[UITabBarController _layoutContainerView]的这段修复逻辑在iOS 12设备上没有被执行。

2. Please help me in this way.

-[CYLTabBarController viewWillLayoutSubviews]中设置tabBarFrame的逻辑是否能被移除？是否能使用autoLayout方法进行布局？ 我翻阅了这段函数前后的日志，发现： frame.origin.y = self.view.frame.size.height - tabBarHeight; 这行代码在前几年曾被短暂改为： frame.origin.y = [UIScreen mainScreen].bounds.size.height - tabBarHeight; 后又被改回。这里当初的背景是？

3. Here is a Demo.

- (void)openAnimation:(id <UIViewControllerContextTransitioning>)transitionContext{
    UIModalPresentationStyle style =  [transitionContext presentationStyle];

    UIView *container = [transitionContext containerView];

    UIView *fromView = [transitionContext viewForKey:UITransitionContextFromViewKey];
    UIView *toView = [transitionContext viewForKey:UITransitionContextToViewKey];

    [container addSubview:fromView];

    self.bgView.frame = container.bounds;
    self.bgView.alpha = 0;
    [container addSubview:self.bgView];

    [container addSubview:toView];

    NSTimeInterval duration = 0.5f;
    fromView.userInteractionEnabled = NO;
    toView.userInteractionEnabled = NO;
    container.backgroundColor = UIColor.clearColor;

    void(^finishBlock)(void) = ^{

        [transitionContext completeTransition:!transitionContext.transitionWasCancelled];
        fromView.transform = CGAffineTransformIdentity;
        toView.transform = CGAffineTransformIdentity;
        toView.userInteractionEnabled = YES;
        fromView.userInteractionEnabled = YES;
        fromView.alpha = 1;
        toView.alpha = 1;
        container.backgroundColor = UIColor.clearColor;
    };

    container.backgroundColor = UIColor.blackColor;
    toView.transform = CGAffineTransformMakeTranslation(toView.frame.size.width, 0);

    [UIView animateWithDuration:duration delay:0 usingSpringWithDamping:1 initialSpringVelocity:0 options:UIViewAnimationOptionCurveLinear animations:^{

        fromView.transform = CGAffineTransformMakeScale(self.scale, self.scale);
        toView.transform = CGAffineTransformIdentity;
        self.bgView.alpha = 1;
    } completion:^(BOOL finished) {
        finishBlock();
    }];
}

4. Here is my Debug log

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