paintComponent with graphics

Question

I'm trying to create a JFrame with 1 image and a text box. I've managed to figure out the text box, but I can't figure the image painting. So far I have this:

public class Patcher extends JFrame {

private static final long serialVersionUID = -431324639043295668L;
private JPanel contentPane;

private static JTextArea textArea;

/**
 * Launch the application.
 */
public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                Patcher frame = new Patcher();
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

/**
 * Create the frame.
 */
public Patcher() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 450, 319);
    contentPane = new JPanel();
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    contentPane.setLayout(new BorderLayout(0, 0));
    setContentPane(contentPane);

    textArea.setBackground(new Color(240, 240, 240));
    textArea.setText("123");
    contentPane.add(textArea, BorderLayout.SOUTH);

    JPanel panel = new JPanel();
    contentPane.add(panel, BorderLayout.NORTH);
    Image img = ImageIO.read(new URL(ClassLoader.getSystemResource("Icon_Entrey_21.png"), "img"));
    ImageObserver imgobs;
    panel.paintComponent(Graphics.drawImage(img, 0, 0, null));
    }
}

The idea is that I create a JPanel , declare an Image using a ClassLoader and try to draw it using paintComponent() method with Graphics as an argument. What am I doing wrong here?

Also I've tried creating a new Graphics() but that throws an error, as well.

Answer 1

1. You should never explicitly call the paintComponent method of any component. If you want to do custom painting, then you would instead create a custom class that extends JPanel/JComponent and @Override the paintComponent method. See more at Performing Custom Painting

    JPanel panel = new JPanel() { @Override protected void paintComponent(Graphics g) { super.paintComponent(g); g.drawImage(...); } // also override getPreferredSize() }; 

2. The easiest, and probably more correct, solution is just to use a JLabel and an ImageIcon instead of trying to custom painting.

    Image img = ImageIO.read(new URL(ClassLoader.getSystemResource("Icon_Entrey_21.png"), "img")); JLabel panel = new JLabel(new ImageIcon(img)); contentPane.add(panel, BorderLayout.NORTH);