JPanel JFrame PaintComponent ||图像未显示到JPanel

Question

请参见以下代码。我正在尝试在JPanel上显示图像。查看屏幕快照。我想在FrameImagePanel上绘制图像。但它不起作用。

package imagetopixelvalue;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 *
 * @author MARUF AHMAD
 */
public class ViewImage extends javax.swing.JFrame {
    public ImagePanel imagePanel;


    /** Creates new form ViewImage */
    public ViewImage() {
        initComponents();

      //  JFrame frame = new JFrame("Testing");
      //          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                this.imagePanel = new ImagePanel();
                FrameImagePanel.add(this.imagePanel);
                FrameImagePanel.setSize(this.imagePanel.getWidth(), this.imagePanel.getHeight());
                System.out.print(" --> "+this.imagePanel.getWidth()+" || "+ this.imagePanel.getHeight());
      //          frame.pack();
       //         frame.setLocationRelativeTo(null);
       //         frame.setVisible(true);
    }


    public class ImagePanel extends JPanel {
         int ImageH =0;
         int ImageW =0;
         BufferedImage imageBuff;

        public ImagePanel(){
            try{
                BufferedImage image = ImageIO.read(new File("image.jpg"));
                imageBuff = image;
                System.out.print(image.getWidth()+" || "+ image.getHeight());
                ImageH = image.getHeight();
                ImageW = image.getWidth();
            }
            catch(IOException e){
            }


        }



        @Override
        public Dimension getPreferredSize() {
            return new Dimension(ImageW, ImageH);
        }
        @Override
        protected void paintComponent(Graphics g){
            super.paintComponent(g);
            g.setColor(Color.red);
            g.drawImage(imageBuff, 0, 0, this);

        }

    }


    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        FrameImagePanel = new javax.swing.JPanel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        FrameImagePanel.setBackground(new java.awt.Color(255, 255, 255));

        javax.swing.GroupLayout FrameImagePanelLayout = new javax.swing.GroupLayout(FrameImagePanel);
        FrameImagePanel.setLayout(FrameImagePanelLayout);
        FrameImagePanelLayout.setHorizontalGroup(
            FrameImagePanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 380, Short.MAX_VALUE)
        );
        FrameImagePanelLayout.setVerticalGroup(
            FrameImagePanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 278, Short.MAX_VALUE)
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(FrameImagePanel, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(FrameImagePanel, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );

        pack();
    }// </editor-fold>

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new ViewImage().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify
    private javax.swing.JPanel FrameImagePanel;
    // End of variables declaration
}

看上面的部分。该代码应该显示图像。 ??此处未添加部分代码。因为stackoverflow不允许太多详细信息代码。

enter image description here

{{1}}

您无需检查所有代码，只需参见上面的部分。