jprogressbar visible and working on button click

Question

public NewJDialog(java.awt.Frame parent, boolean modal) {
    super(parent, modal);
    initComponents();
  jProgressBar1.setVisible(false);

}  

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                     
    jButton1.setEnabled(false);
    jProgressBar1.setVisible(true);        
   repaint();            
   for(int i=0;i<=100;i+=5){
          jProgressBar1.setValue(i);
         // jProgressBar1.setIndeterminate(false);              
          try{
              jProgressBar1.paintImmediately(0, 0, 100, 100);//0, 1, 100, 10
          Thread.sleep(100);
          jProgressBar1.setStringPainted(true);

     }catch(Exception e){}
    }

I use above code for using a Jprogressbar in a JDialog. If I use this I can see a progressbar after completing its process(100 %) and also I don't want to show the progressbar upto buttonclick.

Actaully I want to see a progressbar immediately after button click.But now I get a progressbar which complets its processing — Jisson, Jan 14 '11 at 06:20

score 1 · Answer 1 · answered Jan 19 '11 at 13:23

Use a separate Thread for running your task. The progress bar doesn't have a chance to get painted on the GUI thread. You need something like SwingWorker to help you out.
Add the progress bar to the GUI after the button click.
Refer to the Java tutorial for a walk through on how to set it up.

score 0 · Answer 2 · edited Aug 05 '13 at 07:57

//Simplest way of using JProgressBar

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.sql.*;
import java.util.*;
class logindemo extends JFrame implements ActionListener
   {
      JProgressBar pb;
      JButton b1;
          logindemo()
          {
             super("LOGIN FORM");
             setLayout(null);
             b1=new JButton("LOGIN");
             b1.setBackground(Color.yellow);             
             pb=new JProgressBar(1,100);
             pb.setValue(0);
             pb.setStringPainted(true);
             pb.setForeground(Color.red);   
             pb.setBackground(Color.white); 
             b1.setBounds(20,20,80,25);pb.setBounds(110,20,200,25);
             pb.setVisible(false);
             add(b1);
             add(pb);             
             b1.addActionListener(this);
             setResizable(false);
             setDefaultCloseOperation(EXIT_ON_CLOSE);
          }
           public void actionPerformed(ActionEvent e)
           {
              int i=0;
              if(e.getSource()==b1)
                 {
                   pb.setVisible(true);
                try
                {
                   while(i<=100)
                   {
                    Thread.sleep(50);
    pb.paintImmediately(0, 0, 200, 25);
        pb.setValue(i);
                     i++;
    }
                 }
                 catch(Exception e1)
                 {
    System.out.print("Caughted exception is ="+e1);
                 }
                }
           }
          public static void main(String arg[])
          {
          logindemo m=new logindemo();
          m.setSize(330,100);
          m.setVisible(true);
          Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
          int x = (int) ((dimension.getWidth() - m.getWidth()) / 2);
          int y = (int) ((dimension.getHeight() - m.getHeight()) / 2);
          m.setLocation(x, y); 
          }
   }

/* 
By 
Dr. Amit Kumar Kapoor
Assistant Professor, Maharaja Agrasen Institute of Management & Technology, Jagadhri
E-mail ID: - akbrightfuture@gmail.com
*/

plus there are a couple of other thingies wrong: a) don't sleep the EDT, ever b) don't do any manual sizing/locating of components, that's the exclusive task of a suitable LayoutManager c) paintImmediately is rarely (this is none of the exceptions) needed — kleopatra, Aug 05 '13 at 08:13

jprogressbar visible and working on button click

2 Answers2