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I'm working on an app that's currently localized to two languages. When I build and run the app on a phone or simulator with the system language set to either of the two, everything is displayed in the proper language. However, if I change the system language and re-run the app, all of the strings are displayed in the new language except in UIPickerViews. If I delete and reinstall the app with the new system language, the UIPickerViews are then displayed in the system language - so they're definitely localized strings, but for some reason they don't get updated when I switch languages. How can I force them to be updated when the language is changed?