使用prepareForSegue在视图控制器之间传递数据

Question

I'm trying to create a simple project to pass some data between two view controllers which I have set up using storyboarding.

The project is very simple - on the first page I have a text field, and then a button takes the user to a second view controller where the text should hopefully be displayed, but as of yet no luck.

I am using the 'Modal' style for the Segue, here is the code:

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{

ViewController2 *vc2;

vc2 = [segue destinationViewController];

vc2.label.text = textField.text;    

}

I would be grateful if someone could help me out with the correct code and explain to me why what I currently have doesn't work. I've searched around, and while there seem to be several variations as to how this can be done, this seems pretty much correct to me.

I only moved to iOS from the console about two weeks ago, so please keep it simple!

Thanks in advance!

Answer 1

Your problem (probably!) is that the destinationViewController has not yet loaded its view hierarchy at the point where you're trying to update it. You can verify this with:

NSLog(@"Label: %@", vc2.label);

The way around this is to create a property in ViewController2 that is just a string and set that instead. Then, when viewDidLoad: executes in ViewController2 , copy the string property into the label's text.

Answer 2

I know its ugly but try casting the destinationviewcontroller. I've tried it and it seems to help out with situations such as this.

ViewController2 *vc2 = (ViewController * ) [segue destinationviewcontroller];

Also, if you are using storyboards, are you in a uinavigationcontroller or no?