Objective-C故事板Segue - 将数据从目标传递回sourceViewController

I currently have two view controllers and I linked them up via storyboard segue(navigation controller). When the user presses a button on the first view, the screen goes to the second view. In the second view, there are text fields so that the user can edit the detailed information. When I press the back navigation button, how can I pass that detailed information from the second view controller back to the first view controller?I currently have two view controllers and I lin