[self.view bringSubviewToFront:pickview];
- (void)removeFromSuperview;
- (void)insertSubview:(UIView *)view atIndex:(NSInteger)index;
- (void)exchangeSubviewAtIndex:(NSInteger)index1 withSubviewAtIndex:(NSInteger)index2;
- (void)addSubview:(UIView *)view;
- (void)insertSubview:(UIView *)view belowSubview:(UIView *)siblingSubview;
- (void)insertSubview:(UIView *)view aboveSubview:(UIView *)siblingSubview;
- (void)bringSubviewToFront:(UIView *)view;
- (void)sendSubviewToBack:(UIView *)view;
- (void)didAddSubview:(UIView *)subview;
- (void)willRemoveSubview:(UIView *)subview;
- (void)willMoveToSuperview:(nullable UIView *)newSuperview;
- (void)didMoveToSuperview;
- (void)willMoveToWindow:(nullable UIWindow *)newWindow;
- (void)didMoveToWindow;
- (BOOL)isDescendantOfView:(UIView *)view; // returns YES for self.
- (nullable __kindof UIView *)viewWithTag:(NSInteger)tag; // recursive search. includes self
// Allows you to perform layout before the drawing cycle happens. -layoutIfNeeded forces layout early
- (void)setNeedsLayout;
- (void)layoutIfNeeded;
- (void)layoutSubviews