[Part 3 - Comparing Java & C#] Event and SWING GUI

Today I study way to create GUI and Event in Java. I will use the swing library to create a frame and a label.

Description:

The frame has an event listener which will trigger when a user click the close button.
The label also has an event listener which will trigger when a user click on it.

How I create it:

I extend/inherit the Jframe base class to create a window.
In the main method, I set several options for the frame.
I add event listeners to the frame and the label which both will trigger a popup message .

Result:

Comparing C# against Java:

In c#, I use an event delegate to build event notifications. In Java,I register event listener with the event publisher object, and that object will call a specific predefined method in the event listener when the event occurs.

package myfirst;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
/**
*
* @author chien
*/
public class Myfirst {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here



                SimpleFrame frame = new SimpleFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new GridLayout(3, 1));
                 // Add a window listner for close button
        frame.addWindowListener(new WindowAdapter() {

            public void windowClosing(WindowEvent e) {
                            JOptionPane.showMessageDialog(null, "Close window", "alert", JOptionPane.ERROR_MESSAGE);
                System.exit(0);
            }
        });


        // This is an empty content area in the frame
        JLabel jlbempty = new JLabel("http://proexper.blogspot.com");
                jlbempty.addMouseListener
                (
                        new MouseAdapter()
                        {
                            public void mouseClicked(MouseEvent e)
                            {
                             JOptionPane.showMessageDialog(null, "Click the label", "alert", JOptionPane.ERROR_MESSAGE);
                            }
                        }
                );
                jlbempty.setSize(50, 20);
                jlbempty.setBorder(BorderFactory.createLineBorder(Color.yellow));
        frame.getContentPane().add(jlbempty, BorderLayout.CENTER);
                frame.setVisible(true);


    }

}

class SimpleFrame extends JFrame
{
    private static final int DEFAULT_WIDTH = 300;
    private static final int DEFAULT_HEIGHT = 200;

    public SimpleFrame()
    {
       setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

    }
}

About Chien

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