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();
}
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);
}
}
}