Why doesn't my JFrame show up?

Question

I'm trying to make a solved sudoku puzzle show up in a window with 81 boxes. I did this:

import java.awt.GridLayout;
import java.awt.*;

import javax.swing.JFrame;
import javax.swing.JLabel;


public class GraphicSolver extends JFrame {

GraphicSolver(int[][] spelplan) {

    Panel panel = new Panel(new GridLayout(9,9));

    for(int i=9;i<9;i++){
        for(int x=0;x<9;x++){
            panel.add(new JLabel(""+spelplan[i][x]));
        }
    }

    Frame frame = new Frame();
    frame.add(panel);


    frame.setVisible(true);

}
}

However, it only gives me an empty window without any numbers. I'd be pleased if someone could point me in the right direction.

Can you also post the code that initiates and display the JFrame (your main method or something like that) — Ashkan Aryan, Sep 22 '11 at 09:18

score 7 · Accepted Answer · answered Sep 22 '11 at 09:18

7

The outer loop should start at zero:

for(int i=0;i<9;i++){

answered Sep 22 '11 at 09:18

trashgod

203,806
29
246
1,045

Oh, simple stupid mistake, thanks for pointing it out! I accept this as the answer, as it was the main thing that broke the program. – Filip Hedman Sep 22 '11 at 10:31
Glad to help; also consider up-voting related answers you found helpful. – trashgod Sep 22 '11 at 10:54
See also [`CellTest`](http://stackoverflow.com/questions/4148336/jformattedtextfield-is-not-properly-cleared/4151403#4151403). – trashgod Sep 22 '11 at 17:00

Barak Itkin · Answer 2 · 2011-09-22T09:32:51.810

Try calling frame.pack (), this will pack all the components into the frame to be displayed after computing the correct size with the panels. Also, follow the fix suggested by @trashgod above will solve the fact that no panels were added, and the fix by @Ashkan Aryan will make your code a bit more reasonable (although it should work without it, but then there is no point in inheriting from JFrame).

The code below works for me:

GraphicSolver(int[][] spelplan) {
    Panel panel = new Panel(new GridLayout(9,9));

    for(int i=0;i<9;i++){
        for(int x=0;x<9;x++){
            panel.add(new JLabel(""+spelplan[i][x]));
        }
    }

    this.add(panel);
    this.pack ();
    this.setVisible(true);
}

score 4 · Answer 3 · answered Sep 22 '11 at 09:20

4

You seem to have two Frames. 1 is the JFrame (the class GrpahicSolver itself) and the other a frame that you are creating within it.

I suggest you replace frame.addPanel() with this.addPanel() and it should work.

answered Sep 22 '11 at 09:20

Ashkan Aryan

3,504
4
30
44

score 4 · Answer 4 · answered Sep 22 '11 at 10:41

Graphic Solver

import java.awt.GridLayout;
import javax.swing.*;

public class GraphicSolver {

    GraphicSolver(int[][] spelplan) {
        // presumes each array 'row' is the same length
        JPanel panel = new JPanel(new GridLayout(
            spelplan.length,
            spelplan[0].length,
            8,
            4));

        for(int i=0;i<spelplan.length;i++){
            for(int x=0;x<spelplan[i].length;x++){
                panel.add(new JLabel(""+spelplan[i][x]));
            }
        }

        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(panel);
        frame.pack();

        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                int[][] plan = new int[4][7];
                for (int x=0; x<plan.length; x++) {
                    for (int y=0; y<plan[x].length; y++) {
                        plan[x][y] = (x*10)+y;
                    }
                }
                new GraphicSolver(plan);
            }
        });
    }
}

+1 for spacing; a matching empty border on the panel complements the effect. — trashgod, Sep 22 '11 at 10:55
@trashgod I was going to add a border, but that was 2 whole more lines of code, & I decided to stop there. — Andrew Thompson, Sep 22 '11 at 12:20

Why doesn't my JFrame show up?

4 Answers4