How to exit a method in ActionListener

问题

I have an ActionListener connected to a JTextField and want to type something so that it will exit the method the ActionListener is in.

Code:

main() {
    Security(x,x,x);
}
public void Security(JTextArea out, JTextField in) {
        in.setText("");
        in.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                if (in.getText().contains("exitsys")) {
                    out.append("Security:Security System Deactivated\n");
                    return;
                }
                in.setText("");
            }
        });
        out.append("Security:Security System Activated\n");
        fileWrite(":SYSTEM_INITIATED@" + time(), out);
    }

I want to type "exitsys" and return to the main class method "main()".

The fileWrite method uses a PrintWriter to output data.

QUESTION SUMMARY: I try calling return; but it does not return to the method main(), how do i fix this?

回答1:

Basically what you need is some kind of modal dialog, which will allow you to, effectively, halt the execution of your program at the point the dialog is made visible until the dialog is dismissed (closed), when the execution will continue...

import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JDialog dialog = new JDialog();
                dialog.setTitle("Testing");
                dialog.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                dialog.add(new TestPane());
                dialog.pack();
                dialog.setLocationRelativeTo(null);
                dialog.setVisible(true);

                System.out.println("Now back in the main...");
            }
        });
    }

    public class TestPane extends JPanel {

        private JTextField field;

        public TestPane() {

            setLayout(new GridBagLayout());

            field = new JTextField(10);
            field.addActionListener(new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent e) {
                    if ("exitsys".equals(field.getText())) {
                        SwingUtilities.getWindowAncestor(field).dispose();
                    }
                }
            });

            add(field);

        }

    }

}

See How to Make Dialogs for more details

来源：https://stackoverflow.com/questions/27560703/how-to-exit-a-method-in-actionlistener

标签

java

swing

methods

actionlistener

jtextfield