How to catch a change in UITextField text?
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I have looked at all the similar questions and they are different than from what I am asking. I need to catch a change in the actual text in the UITextField, not just the state of editing. It will be a first responder when the view loads, and I need to know when text is entered so that I can enable "Next" in the navigation bar. Please help me if you can it's really holding me back in my project.

Addition: I am currently using - it doesn't work:
    
    [textField addTarget:self action:@selector(textFieldDidChange)    forControlEvents:UIControlEventValueChanged];