I've got a universal project here with storyboard. I've created a subclass of UIWindow called MyWindow, and I need to load it instead of the default UIWindow. Prior to storyboard, I would simply go to the .XIB file in XCode and change the class for the main window to MyWindow. However, I'm unable to find any section where I can change this in storyboard.
Does anyone know where I can do this? I need the main window to load MyWindow, not UIWindow.
When using storyboards the application delegate and main window are no longer represented in Interface Builder. Instead, when your app starts, your app delegate is queried for a property called 'window'. If this returns nil then a default window of type UIWindow is created for you. To change this behaviour you need to implement a 'window' getter method in your app delegate that returns your 'MyWindow' subclass. See the documentation.
来源：https://stackoverflow.com/questions/7883886/where-can-i-change-the-window-my-app-uses-from-uiwindow-to-my-own-subclass-mywi