Question

java编程窗体上有黑色和白色两个按钮一个标签单击黑色按钮窗体颜色变成黑色单

Answer 1

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;import javax.swing.JFrame;
import javax.swing.JOptionPane;public class SimpleFrame {public static void main(String[] args) {

MyFrame frame = new MyFrame();
frame.setDefaultCloseOperation( JFrame.DO_NOTHING_ON_CLOSE);
frame.setVisible(true);
}
}
class MyFrame extends JFrame
{
public MyFrame()
{
this.setSize( 300, 200);
this.setResizable( false);
this.addWindowListener(new MyListener(this));
}

private class MyListener extends WindowAdapter
{
JFrame myFrame;
public MyListener( JFrame f)
{
myFrame = f;
}
@Override
public void windowClosing(WindowEvent arg0) {
int test = JOptionPane.showConfirmDialog( myFrame, "确定要退出吗?","退出确认",
JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);
if( test == JOptionPane.YES_OPTION)
System.exit(0);
else
return;
}
}
}