在UITabBarController中的屏幕之间共享信息

Question

I have UITabBarController, containing 2 screens - A,B. I also have a strings array - strArr in my application delegate (this array is a global variable).

Screen A changes strArr. Screen B contains UIPickerView that displays the values from strArr.

The problem: When I see screen B, I can see the updated values from the strArr array in the picker. BUT, after I'm changing the values of strArr in Screen A, switching to screen B and watching the spinner, I still see the old values, and the app crashes when I'm selecting non-existing anymore item from the picker...

The question (You've probably already know what I'm about to ask..): How can I display the updated values in the picker that located on screen B?

Thanks all.

Answer 1

如果您的数据模型的一部分发生了变化，而应用程序的其余部分需要了解它，则可以使用键值观察或通知 。