create a mac app,click button to change label text? create project,click left window button on Main.storyboard,click ViewController on the left,drag push button and label to view controller,use duo code and ui framework with suit icon,ctrl-drag label and button named myLabel and myButton to create IBOutlet in ViewController.h,ctrl-drag button named myButton to create IBAction in ViewController.m,inner sender enter _myLabel.stringValue=@"love"; to change label text remove git from xcode to avoid xcode read history code.