To do this, control-drag from the Text Field right before the @end and also set it to Action. By default it sets the event to Editing Did End – change this to Editing Changed. Name the method titleFieldTextChanged, and click Connect.
The last thing you have to do is set your class as the delegate of the text field. Sometimes receiving callbacks on actions of a view isn’t enough – they might have other information to tell you about, and the text field is an example of this.
To do this, control-click on the Text Field, and drag a line from the little circle to the right of the delegate entry up to the Detail View Controller, and release.