UITabBarController的活用(根據場景隱藏顯示TabBar)

UITabBarController的活用，UITabBarController+UINavigationController的架構中會用到。

1.隱藏TabBar：

- (void)hideTabBar {
    if (self.tabBarController.tabBar.hidden == YES) {
        return;
    }
    UIView *contentView;
    if ( [[self.tabBarController.view.subviews objectAtIndex:0] isKindOfClass:[UITabBar class]] )
        contentView = [self.tabBarController.view.subviews objectAtIndex:1];
    else
        contentView = [self.tabBarController.view.subviews objectAtIndex:0];
    contentView.frame = CGRectMake(contentView.bounds.origin.x,  contentView.bounds.origin.y,  contentView.bounds.size.width, contentView.bounds.size.height + self.tabBarController.tabBar.frame.size.height);
    self.tabBarController.tabBar.hidden = YES;

}

2.顯示TabBar：

- (void)showTabBar

{
    if (self.tabBarController.tabBar.hidden == NO)
    {
        return;
    }
    UIView *contentView;
    if ([[self.tabBarController.view.subviews objectAtIndex:0] isKindOfClass:[UITabBar class]])

        contentView = [self.tabBarController.view.subviews objectAtIndex:1];

    else

        contentView = [self.tabBarController.view.subviews objectAtIndex:0];
    contentView.frame = CGRectMake(contentView.bounds.origin.x, contentView.bounds.origin.y,  contentView.bounds.size.width, contentView.bounds.size.height - self.tabBarController.tabBar.frame.size.height);
    self.tabBarController.tabBar.hidden = NO;

}