import java.awt.Color;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;
public class Main {
public static JComponent makeUI() {
JPanel p = new JPanel();
p.setBackground(new Color(.5f, .5f, .5f, .5f));
p.add(new JComboBox<String>(new String[] { "aaa", "bb", "c" }));
JComboBox c = new JComboBox<String>(new String[] { "aaa", "bb", "c" });
p.add(c);
return p;
}
public static void main(String[] args) {
JFrame.setDefaultLookAndFeelDecorated(true);
JFrame f = new JFrame();
f.setBackground(new Color(0, true)); // 1.7.0
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.getContentPane().add(makeUI());
f.setSize(320, 240);
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}