java - 在透明 JFrame 上添加图像

Question

我想在透明的 JFrame 上显示图像。
图片显示不清晰。如果我添加任何组件，如 JButton 或任何其他组件，它会显示得很好，除了任何内部有图像的组件。

这是一个代码示例。

import java.awt.Color;
public class PunchFrame2 extends javax.swing.JFrame {

    public PunchFrame2() {
        initComponents();
        setUndecorated(true);
        setBackground(new Color(0,0,0,0));
    }

    /**
     * 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() {

        jPanel1 = new javax.swing.JPanel();
        jLabel2 = new javax.swing.JLabel();
        jLabel1 = new javax.swing.JLabel();
        jLabel3 = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBackground(java.awt.Color.black);

        jLabel2.setFont(new java.awt.Font("Ubuntu", 1, 48)); // NOI18N
        jLabel2.setForeground(java.awt.Color.white);
        jLabel2.setText("Steve Jobs");

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING,             jPanel1Layout.createSequentialGroup()
            .addContainerGap(234, Short.MAX_VALUE)
            .addComponent(jLabel2)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addComponent(jLabel1)
            .addGap(23, 23, 23))
    );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jLabel2)
            .addContainerGap(21, Short.MAX_VALUE))
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING,      jPanel1Layout.createSequentialGroup()
            .addGap(0, 0, Short.MAX_VALUE)
            .addComponent(jLabel1))
    );

    jLabel3.setIcon(new javax.swing.ImageIcon("/home/username/Desktop/stevejobs.png")); // NOI18N

    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(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addContainerGap())
        .addGroup(layout.createSequentialGroup()
            .addGap(200, 200, 200)
            .addComponent(jLabel3)
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jLabel3)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
    );

    java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
    setBounds((screenSize.width-545)/2, (screenSize.height-290)/2, 545, 290);
}// </editor-fold>                        

/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new PunchFrame2().setVisible(true);
        }
    });
}
// Variables declaration - do not modify                     
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JPanel jPanel1;
// End of variables declaration    }

我尝试了很多东西，比如jLabel1.setOpaque(false);但徒劳无功。

如何解决这个问题？

使用的图片:

结果:

Answer 1

您只需调用 setVisible(true)。但默认的 JFrame 宽度和高度为零。它不会展开 JFrame。

尝试设置JFrame的大小。有两种方式:

PunchFrame2 frame = new PunchFrame2();

1. frame.pack();//或

2. frame.setSize(300,300);

   frame.setVisible(true);