JFrame背景色未正确更改

Question

I am creating an application that creates a ton of JFrames with different background colors. At first they are the correct colors (Black and Red) but then all the new ones stay white.

import java.awt.Color;
import java.util.Random;

import javax.swing.JFrame;

public class JFrameCrash{

    private Random r;
    private int screenHeight;
    private int screenWidth;

    private static final int FRAME_HEIGHT = 100;
    private static final int FRAME_WIDTH = 200;
    //private static final Color[] COLORS = {Color.RED, Color.BLUE, Color.GREEN, Color.YELLOW, Color.BLACK, Color.WHITE, Color.GRAY, Color.CYAN, Color.PINK, Color.MAGENTA, Color.ORANGE};
    private static final Color[] COLORS = {Color.RED, Color.BLACK};

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

    public JFrameCrash(){
        screenHeight = java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds().height;
        screenWidth = java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds().width;
        r = new Random();
        loop();
    }

    public JFrameCrash(int height, int width, Random rand){
        this.screenHeight = height;
        this.screenWidth = width;
        r = rand;
        run();
    }

    private void loop(){
        while (true){
            new JFrameCrash(screenHeight, screenWidth, r);
        }
    }

    private void constructFrame(){
        JFrame frame = new JFrame();
        frame.setTitle("");
        frame.setLocation(r.nextInt(screenWidth), r.nextInt(screenHeight));
        frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
        frame.getContentPane().setBackground(COLORS[r.nextInt(COLORS.length)]);
        frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
        frame.setResizable(false);  
        frame.setVisible(true);
    }
}

Answer 1

hmm.. interesting one.. try to give it some sleep, give some delay time..

it will depend on your computer spec. though.. in my case, I need to give around 100ms delay per frame creation.. and it can still works well up to 444 frames, then I just stopped it..

if I reduce it to 50ms delay, I got the same experience as you at around 200-ish creation..

have a fun programming~

import java.awt.Color;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class JFrameCrash {

    private Random r;
    private int screenHeight;
    private int screenWidth;

    private static final int FRAME_HEIGHT = 100;
    private static final int FRAME_WIDTH = 200;
    //private static final Color[] COLORS = {Color.RED, Color.BLUE, Color.GREEN, Color.YELLOW, Color.BLACK, Color.WHITE, Color.GRAY, Color.CYAN, Color.PINK, Color.MAGENTA, Color.ORANGE};
    private static final Color[] COLORS = {Color.RED, Color.BLACK};

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

    public JFrameCrash() {
        screenHeight = java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds().height;
        screenWidth = java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds().width;
        r = new Random();
        loop();
    }

    public JFrameCrash(int height, int width, Random rand) {
        this.screenHeight = height;
        this.screenWidth = width;
        r = rand;

        constructFrame();
        //run();
    }

    private void loop() {
        int i = 0;
        while (true) {
            new JFrameCrash(screenHeight, screenWidth, r);
            try {
                Thread.sleep(100);
            } catch (InterruptedException ex) {
                Logger.getLogger(JFrameCrash.class.getName()).log(Level.SEVERE, null, ex);
            }
            i++;
            System.out.println(i);
        }
    }

    private void constructFrame() {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.setTitle("");
                frame.setLocation(r.nextInt(screenWidth), r.nextInt(screenHeight));
                frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
                frame.getContentPane().setBackground(COLORS[r.nextInt(COLORS.length)]);
                frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
                frame.setResizable(false);
                frame.setVisible(true);
            }
        });

    }
}