如何強制將ImageIcon設爲特定尺寸？

Question

目前，我用這個代碼：

public class Test extends JFrame { 
static Test t = null; 
public static void main(String[] args) { 
    EventQueue.invokeLater(new Runnable() { 
     public void run() { 
      try { 
       t = new Test(); 
      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
     } 
    }); 
} 

public static void addComponentsToPane(Container pane) { 

    JButton button; 
    pane.setLayout(new GridBagLayout()); 
    GridBagConstraints c = new GridBagConstraints(); 

    ImageIcon icon; 
     icon = new ImageIcon(System.getProperty("user.dir") + "/res/background.png"); 
    Image img = icon.getImage() ; 
     Image newimg = getScaledImage(img, frame.getWidth(), frame.getHeight()) ; 
     icon = new ImageIcon(newimg); 
    JLabel background=new JLabel(icon); 

     //frame.getContentPane().add(background); 

     background.setLayout(new FlowLayout()); 

    c.fill = GridBagConstraints.HORIZONTAL; 
    c.ipady = frame.getHeight() * 10; 
    c.weightx = 0.0; 
    c.gridwidth = 3; 
    c.gridx = 0; 
    c.gridy = 1; 

    pane.add(background, c); 


} 
private static Image getScaledImage(Image srcImg, int w, int h){ 
    BufferedImage resizedImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); 
    Graphics2D g2 = resizedImg.createGraphics(); 
    g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR); 
    g2.drawImage(srcImg, 0, 0, w, h, null); 
    g2.dispose(); 
    return resizedImg; 
} 

private void createAndShowGUI() { 
    frame = new JFrame("GridBagLayoutDemo"); 
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
} 

static JFrame frame = null; 

public Test() { 

    createAndShowGUI(); 
    addComponentsToPane(frame.getContentPane()); 
    frame.pack(); 
    frame.setVisible(true); 
    frame.setExtendedState(frame.getExtendedState() | JFrame.MAXIMIZED_BOTH); 
} 

} 

這工作正常的按鈕，但由於某種原因未與圖像工作的JLabel。 我該如何讓這個JLabel/Image適合我想要的尺寸？

圖像被此刻真的很小， 時候，確實，與一個JButton相同的代碼佔用面積更是這樣的： 此外，它可以讓我得到的ImageIcon比按鈕4還要大，這也是我想避免的。

那麼，我該如何拉伸/收縮圖像以適合我希望它具有的區域？

Answer 1

所以，我怎麼能伸展/收縮圖像，以適應我想它有什麼地方呢？

查看Darryl的Stretch Icon。圖標會自動以組件的大小繪製。

Answer 2

你可以使用代碼片段從http://docs.oracle.com/javase/tutorial/displayCode.html?code=http://docs.oracle.com/javase/tutorial/uiswing/examples/components/IconDemoProject/src/components/IconDemoApp.java創建縮放圖像... （從http://docs.oracle.com/javase/tutorial/uiswing/components/icon.html）

只是衡量你按鈕，調整圖像尺寸

/** 
* Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved. 
* Resizes an image using a Graphics2D object backed by a BufferedImage. 
* @param srcImg - source image to scale 
* @param w - desired width 
* @param h - desired height 
* @return - the new resized image 
*/ 
private Image getScaledImage(Image srcImg, int w, int h){ 
    BufferedImage resizedImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); 
    Graphics2D g2 = resizedImg.createGraphics(); 
    g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR); 
    g2.drawImage(srcImg, 0, 0, w, h, null); 
    g2.dispose();   
    return resizedImg; 
} 

我要拿起來自MadProgammer的關於使用scaledInstance的提示：https://today.java.net/pub/a/today/2007/04/03/perils-of-image-getscaledinstance.html

那麼如何測量按鈕尺寸？

final Button b = new Button(); //create it on your custom way... 
b.addComponentListener(new ComponentAdapter() { 

    @Override 
    public void componentResized(ComponentEvent e){ 
     int w = b.getWidth(); 
     int h = b.getHeight();    
     setIconSize(w,h); //TODO by yourself (sorry, if more help required please say so) 
    } 
});