问题
I have 1 main Master screen (MVC) and 4 other screens that share ~80% of graphic objects. They differ in some label texts, a button with action and some other 20% graphics. Thinking in terms of clean object oriented code architecture, I have started to implement those screens as separate UIViewControllers. But I didn't like having pointers to those 4 MVCs and a duplication of some methods, so I rewrited the code into one UIViewController. Most of graphic objects are UIImageViews that I put on with Interface Builder. So, now the xib file of that "unified" UIViewController is a little bit bloated with overlapping objects from those 4 screens. I also need to have those methods like showScreen1, hideScreen2, showScreen2, hideScreen2, and other methods, so I'm not very happy with this architecture too. I understand that I should not mix those 4 MVCs (screens) and both the code, and xib files would be cleaner but I'm also thing about performance, saving memory loads and etc. What would be your opinions on that? How much memory resources takes the loading of separate UIViewController? Maybe the amount of saved memory is not worth when compared to code cleanness? Again, having 4 separate MVC's would force me to have 4 pointers both to my Master MVCs and 4 pointers to those separate MVCs from my Master MVC, because I need to communicate and navigate between those screens. Another option would to use notifications instead of pointers but it doesn't change the amount of required relations. So please share your thoughts and insights :)
回答1:
For user interface controls that share the same design perhaps you could use categories, this is what I'm doing in a project. I've added a category to UINavigationBar to show a texture on the bar, added a category to UIBarButtonItem / UIButton for a back & cancel button and since my ViewControllers all share the same background image I've created a UIViewController subclass that contains the default background image - every view controller used in my app inherits from this default view controller.
I would stick with 1 view controller per screen.
Apple doesn't recommend creating giant nibs, this is especially visible in the WWDC 2011 video on storyboarding (check this video out if you're a registered Apple developer). Giant nibs are bad in terms of performance, it takes a lot of time to load all objects and all the objects from the nib stay in memory all the time, even if the objects are on a screen that's currently not being displayed. It's a better approach to have a separate nib per screen.
来源：https://stackoverflow.com/questions/6974301/how-to-design-code-architecture-when-overlapping-objects-exist