Changing background color

[nikkka]

That is the code of the simple program that generates frame with some basic parameters. It's all okay except one thing: it doesn't change the background color to RED. Why is that?

import java.awt.*;
import javax.swing.*;
public class FirstSwing {
	public static void main(String[] args) {
		SimpleFrame f = new SimpleFrame();
		f.setBackground(Color.RED);
		f.showIt("my first window", 400, 300);
	}
}
class SimpleFrame extends JFrame {
	public SimpleFrame() {
		this.setSize(200,200);
		this.setLocation(200,200);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	public void showIt(String s) {
		this.setTitle(s);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setVisible(true);
	}
	public void showIt(String s, int x, int y) {
		this.setTitle(s);
		this.setSize(x, y);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setVisible(true);
	}
	public void hideIt() {
		this.setVisible(false);
	}
	public void showIt() {
		this.setVisible(true);
	}
	
}

[sunde887]

What have you tried to solve it?

[nikkka]

Well, the thing is that every time when I run the program, the frame IS red for a fraction of second, and then it's changed to default-grey again.

[sunde887]

What happens if in the showIt method you overload it to take a color and set the color in the method? Also, try and use print lines to print the current value of the background with getBackground()

[pbrockway2]

Typically you add/remove/alter and view not so much the frame as the content pane which holds all the nonmenu items.

So,

public static void main(String[] args) {
	SimpleFrame f = new SimpleFrame();
	f.getContentPane().setBackground(Color.RED);
	f.showIt("my first window", 400, 300);
}

I would recommend working through a decent Tutorial rather than trying to figure out what might not be completely intuitive. The Creating a GUI With JFC/Swing section of Oracle's Tutorial is good. Others may be able to suggest something that aims more at introducing and less at being comprehensive.