repaint in Java

Question

Possible Duplicate    Java GUI repaint   problem        I write a Java code  but I have a trouble with GUI problem  When I add a component into JFrame object  then I call repaint   method in order to update the GUI but it doesn t work  But when I minimize or resize this frame  the GUI is updated   Here is my code   public static void main String   args        JFrame frame   new JFrame         frame setSize 460  500       frame setTitle  Circles generator        frame setDefaultCloseOperation JFrame EXIT ON CLOSE        frame setVisible true        String input   JOptionPane showInputDialog  Enter n         int n   Integer parseInt input        CircleComponent component   new CircleComponent n       frame add component       component repaint

User · Answer

Simply write     frame validate    frame repaint      That will do    Regards

User · Answer

You may need to call frame repaint   as well to force the frame to actually redraw itself  I ve had issues before where I tried to repaint a component and it wasn t updating what was displayed until the parent s repaint   method was called

User · Answer

If you added JComponent to already visible Container  then you have call  frame getContentPane   validate    frame getContentPane   repaint      for example  import java awt Color  import java awt Dimension  import java awt Graphics  import javax swing JFrame  import javax swing JLabel  import javax swing JOptionPane   public class Main        public static void main String   args            JFrame frame   new JFrame            frame setSize 460  500           frame setTitle  Circles generator            frame setDefaultCloseOperation JFrame EXIT ON CLOSE            SwingUtilities invokeLater new Runnable                 public void run                   frame setVisible true                                     String input   JOptionPane showInputDialog  Enter n             CustomComponents0 component   new CustomComponents0            frame add component           frame getContentPane   validate            frame getContentPane   repaint               static class CustomComponents0 extends JLabel            private static final long serialVersionUID   1L            Override         public Dimension getMinimumSize                 return new Dimension 200  100                       Override         public Dimension getPreferredSize                 return new Dimension 300  200                       Override         public void paintComponent Graphics g                int margin   10              Dimension dim   getSize                super paintComponent g               g setColor Color red               g fillRect margin  margin  dim width - margin   2  dim height - margin   2

User · Answer

You re doing things in the wrong order   You need to first add all JComponents to the JFrame  and only then call pack   and then setVisible true  on the JFrame  If you later added JComponents that could change the GUI s size you will need to call pack   again  and then repaint   on the JFrame after doing so

[java] repaint() in Java

Examples related to java

Examples related to swing

Examples related to graphics

Examples related to validation

Examples related to repaint