how to draw on Jwindow?

[T.H. Ng]

I'm starting to learn how to use GUI and this is my first Problem: The line that i want to draw never show up. What am I doing wrong?

    
import java.awt.*;
import java.awt.geom.*;
import java.awt.image.*;
import javax.swing.*;
import java.awt.event.*;
	 
	public class exp extends JPanel {
	   private JWindow window;
           
	   public exp() {
            window = new JWindow();
            window.setSize(600,350);
                       
            //Create Mouse Listener that listen when someone click on that JWindow  
            MouseListener ml=new MouseAdapter(){  
            public void mousePressed(MouseEvent evt){
                System.exit(0);}
            };   
            window.addMouseListener(ml); 
            window.setVisible(true);                  
            }
	     
	    public void paint(Graphics g) {                
	        g.drawLine(50,50,50,50);
	    }
	 
	    public static void main(String[] args) {
	    new exp();
	      } 
	}

[Stephan van Hulst]

You might want to add your panel to the window.

[T.H. Ng]

hmm how can i do that? Sorry for the stupid question

[Stephan van Hulst]

window.add(this);

Have you ever worked with GUIs before? I suggest getting familiar with regular JFrames first. Check out the Swing tutorials: click

[T.H. Ng]

i tried that as you said, but still no good.

[Stephan van Hulst]

Are you sure? Your current code only draws a single pixel. Try changing the arguments to the drawLine method to something like 50, 50, 100, 50.

[T.H. Ng]

yh i have tried with JFrame, there is no problem so far, just cant understand whats happening here...

[T.H. Ng]

I also tried with g.fillRect(50,50,50,50); but it still doesnt show up

[Darryl Burke]

You have been given a link to the Swing tutorials. Go through the section titled Performing Custom Painting, where you will find example code.

[T.H. Ng]

sorry i tried but all i found out is the component doesn's show up Can you please give me the solution for those codes? Thank you very much!

[Stephan van Hulst]

Your program (when modified to add the panel to the window) runs just fine for me.

Can you post your modified code?

[T.H. Ng]

well i only add "window.add(this);" betweens line 20 and 21

[T.H. Ng]

oh ic, i should put window.setVisible(true); before window.add(this); (i dont know why tho:P). Thank you all for helping me

[Stephan van Hulst]

No, you should add the panel *before* you show the window. This can be as early as right after you initialize window.

I don't know why it didn't work for you earlier (probably because your IDE needed to clean the build, or you forgot to compile or something), but it wasn't a problem with the code.

[T.H. Ng]

now i understand problem solved! ty verymuch!