如何在iPhoneX中为顶部设置背景颜色

I just realise that my app is not working for iphoneX's design. I have a UIVIew (containing textfield and button) tends to be like navigation bar so it does support for iPhone 8 and 8 plus. However, the iPhoneX has blank white for the top section. Vice versa, if I set the Uiview to act like navigation bar, then the iphone8 and 8plus will have higher gap between the textfield and top layout. May I know how can I set the constraint that fits for all version or other way to add for the top section and it also changed when landscape mode. Many thanks!I just realise that my app is not working for i