图片将不会在JLabel中显示

Question

我使用NetBean内置的GUI构建器创建了一个Gui，现在我试图添加允许用户选择图片的代码，该图片应该显示在A JLabel中的ImageIcon中，但我可以没有得到要显示的图像。

private void jButton2MouseClicked(java.awt.event.MouseEvent evt) {          
    CardLayout cl = (CardLayout)(mainPanel.getLayout());   
    cl.show(mainPanel, "uploadImage"); 

    File im1 = null; 
    JFileChooser chooser = new JFileChooser(); 
    FileNameExtensionFilter filter = new FileNameExtensionFilter(
      "JPG, GIF, PNG Images", "jpg", "gif", "png"); 
     chooser.setFileFilter(filter); 
     int returnVal = chooser.showOpenDialog(mainPanel); 

    try { 
     if(returnVal == JFileChooser.APPROVE_OPTION) {  
       im1 = chooser.getSelectedFile(); 
     } 
     else { 
      throw new IOException(); 
     } 
     BufferedImage buff = ImageIO.read(im1); 

     BufferedImage resizedImage = new BufferedImage(imagePanel.getWidth(), imagePanel.getHeight(), BufferedImage.TYPE_INT_RGB); 
     Graphics2D g = resizedImage.createGraphics(); 
     g.drawImage(buff, 0, 0, imagePanel.getWidth(), imagePanel.getHeight(), null); 
     g.dispose();   

     JLabel picLabel = new JLabel(new ImageIcon (resizedImage)); 
     picLabel.setVisible(true); 

     imagePanel.add(picLabel);// this is the Jpanel that should displpay the image 
     this.validate(); // this refers to the frame that holds all of the components 
    } catch (IOException ex) { 
     Logger.getLogger(MainFrame.class.getName()).log(Level.SEVERE, null, ex); 
    } 
}  

我试过验证并重新验证框架和面板图像图标，但似乎没有任何工作。任何帮助是极大的赞赏。

Answer 1

添加图像后，您可以尝试repaint（）方法。