How can I insert a subview below the other subviews
If you Google UIView you'll end up at the documentation - UIView Class Reference
Then you need to look down the list of methods until you find something that sounds like it will roughly fit your needs like these two:
- (void)insertSubview:(UIView *)view atIndex:(NSInteger)indexand
- (void)insertSubview:(UIView *)view belowSubview:(UIView *)siblingSubviewAt this point you just have to read the descriptions of how the methods behave and pick whichever one is easiest to implement for your design. It's really good for your own learning if you try to find the answer yourself before you ask a question
You can call this method in Swift 3
view.insertSubview(yourSubView, at: 0)or
view.sendSubview(toBack: yourSubView)