我如何访问UITextField的文本值iOS Swift 4

Question

I am new to ios programming and this may be me being very stupid (quite likely).

I have two viewcontrollers in my app. To view the second viewcontroller i use a seque and then return to the first viewcontroller with the back button on the seconf viewcontroller navigation bar. This all works fine.

On the second viewcontroller i have a UITextField which is populated following a background notification event with text returned from an external class.

The first time i seque to the second viewcontroller and trigger the event to populate the UITextField it works correctly.

If i then go back to the first viewcontroller and then seque to the second viewcontroller a second time, the UITextField will not update.

I suspect that each time i seque to the second viewcontroller, i am creating a new instance of that controller and when i try and update the UITextField i am still updating the first instance of the viewcontroller which is not visible.

It fells as though i should address the UITextField in someway like UITextFied[current viewcontroller].text = "Hello World".

Any help or guidance would be much appreciated.

Thanks

Answer 1

I not sure if I understand your problem but its sound like you define your background notification event in viewDidLoad in first view controller try it in viewDidApper or viewWillApper

ViewDidLoad only call ones on its first load