Help in 2d Graphics in Swing

Question

In my program, you click on a JPanel and a picture should display. The code has no errors, it just doesn't work. Here's the code:
private void jPanel100MousePressed(java.awt.event.MouseEvent evt) {
String imageFile = "corn.gif";
Image image = Toolkit.getDefaultToolkit().getImage(imageFile);
int iw = 200;
int ih = 200;
BufferedImage bi = new BufferedImage(iw, ih, BufferedImage.TYPE_INT_RGB);
Graphics2D big = bi.createGraphics();
big.drawImage(image,0,0,this);
I do have a file named "corn.gif" in the same folder as the program, which is in the same folder as the compiler and the runner of the program. But why doesn't my picture display?

Answer 1

The strategy is to first create your BufferedImage, create a component who will draw the image in itself and then control the painting from within your event code.
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;
public class ImageDisplay {
  static BufferedImage bi;
  static boolean showBI = true;
  static JPanel panel;
  public static void main(String[] args) {
    String imageFile = "images/cougar.jpg";
    File file;
    Image image = null;
    try {
      file = new File(imageFile);
      image = ImageIO.read(file);
    catch(FileNotFoundException fnf) {
      System.out.println(fnf.getMessage());
    catch(IOException ioe) {
      System.out.println(ioe.getMessage());
    int w = image.getWidth(null);
    int h = image.getHeight(null);
    bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
    Graphics2D g2 = bi.createGraphics();
    g2.drawImage(image, 0, 0, null);
    g2.dispose();
    panel = new JPanel() {
      public void paintComponent(Graphics g) {
        super.paintComponent(g);
        int w = getWidth();
        int h = getHeight();
        int biWidth = bi.getWidth();
        int biHeight = bi.getHeight();
        if(showBI)
          g.drawImage(bi, (w - biWidth)/2, (h - biHeight)/2, null);
    panel.setBackground(Color.pink);
    final JButton showButton = new JButton("show image");
    final JButton removeButton = new JButton("remove image");
    ActionListener l = new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        JButton button = (JButton)e.getSource();
        if(button == showButton) {
          showBI = true;
          panel.repaint();
        if(button == removeButton) {
          showBI = false;
          panel.repaint();
    showButton.addActionListener(l);
    removeButton.addActionListener(l);
    JPanel southPanel = new JPanel();
    southPanel.add(showButton);
    southPanel.add(removeButton);
    JFrame f = new JFrame();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.getContentPane().add(panel);
    f.getContentPane().add(southPanel, "South");
    f.setSize(400,400);
    f.setLocation(400,300);
    f.setVisible(true);
}