问题:

My app is suddenly unable to correctly display UIDatePickers. I'm using storyboards. The Datepickers are set to just display the date. They are cutting off the month, and also not even showing the days. There's a big space in the middle. I have tried cleaning the project, resetting the simulator, checking localization settings, and checking to see if dynamic type size was set. I'm using Xcode 5.1.1 but the same thing happens in the beta of Xcode 6. Any suggestions would be appreciated.

回答1:

Ok, I figured it out. This happened as a result of trying to use UIAppearance on a tableView background color. This has nothing to do with tableViews on the face of it, but Apple must be using a tableView privately for the PickerViews. So, my attempt to set a UIAppearance via a category on a tableView background color seems to be doing something unexpected. Lesson learned. Don't try to use UIAppearance where they are not officially supported.

回答2:

I had this exact same issue, and it was related to duplicate constraints in my storyboard. I'd been implementing iPhone 6 widths and inadvertently ended up with both width = 320 and width >= 320. Removing that width = 320 fixed it instantly.