Question

I have a class like this:

public class A {
    public static void main() {
        B f1 = new B();
        f1.setVisible(true);
    }

    class B extends JFrame {
        public B() {
            JButton btn = new JButton("click me");
            btn.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent evt) {
                    C f2 = new C();
                    f2.setVisible(true);
                }
            });
            add(btn);
        }
    }

    class C extends JFrame {
        public C() {
            //whatever here
        }
    }
}

When I first run this java code,
a window X contains a button “click me”. After I click it, another new window Y is popped out.
But the problem is that when I close the new window Y, the old window X is closed together with Y automatically. (i.e. they are closed at the same time)

What I wanna do is that after I close Y, X keeps there and not to be closed. How to do it?

Answer 1

You would change the argument of the setDefaultCloseOperation() method, which defines what happens when the close button is clicked. In this case, you would use DISPOSE_ON_CLOSE as the argument. The reason both frames are being disposed is presumably because you set the argument to EXIT_ON_CLOSE (if you didn’t set this explicitly, then it was done for you; it is the default close behavior for all frames) which terminates the entire process—this includes all open windows and frames. If you need further assistance, please ask. 🙂