JLabel 中有两个图标？

Posted 2023-02-16

【中文标题】JLabel 中有两个图标？

【英文标题】：Two icons in a JLabel?

【发布时间】：2011-12-16 19:02:15

【问题描述】：

我在 JLabel 中有一个图标，如下所示：

是否可以在彩色图标和文本之间添加另一个图标（例如代表国家的国旗）？例如，我想在红色图标和US 之间添加一个描绘美国国旗的图标。谢谢！

【参考方案1】：

试试CompoundIcon 编辑：Heisenbug 的基于布局的解决方案是 简单的答案。

【讨论】：

或将容器嵌套在布局中。或为此目的在列表中添加另一列。

【参考方案2】：

这很有可能，JLabel 是 Swing JComponent，您可以将任何 JComponent 添加到另一个 JComponent，对于 JLabel 也是如此

label.setLayout(new GridLayout(0, 2, 10, 10));
label.add(myIcon1);
label.add(myIcon2);

如果你添加 f.e. JPanel 到 JLabel 然后别忘了setOpaque(false);

【参考方案3】：

我最近才这样做 - 我希望能够将单行中的多个图标组合成一个图标。我这样做的方法是下降到BufferedImage 级别并将两个图像手动组合成一个图像，然后将其用作我的JLabel 图标。还有其他方法可以达到相同的效果，但我不想更改我的 UI 组件层次结构。

我最终创建了一个组合多个图像并缓存它们的类。我是这样使用的：

ImageIcon icon1 = ...;
ImageIcon icon2 = ...;

ImageIcon labelIcon = new CachedCompositeIcon( icon1, icon2 ).getIcon();
jLabel.setIcon( labelIcon );

来源：

/** This is a convenience class to handle creating a single composite icon from several icons, and caching the
 *  created icons to eliminate duplicate work. This class is basically used as a key into a map, allowing us to
 *  define both a hashCode and equals in a single place.
 */
public class CachedCompositeIcon

    private static final byte ICON_PADDING = 2;
    private static final HashMap<CachedCompositeIcon, ImageIcon> CACHED_ICONS =
            new HashMap<CachedCompositeIcon, ImageIcon>( 4 );

    private final ImageIcon[] m_icons;

    public CachedCompositeIcon(final ImageIcon... icons) 
        m_icons = icons;
    

    public ImageIcon getIcon() 
        if ( !CACHED_ICONS.containsKey( this ) ) 
            CACHED_ICONS.put( this, lcl_combineIcons() );
        

        return CACHED_ICONS.get( this );
    

    /** Generates an icon that is a composition of several icons by appending each icon together with some
     *  padding between them.
     *
     * @return An icon that is the concatenation of all the icons this was constructed with.
     */
    private ImageIcon lcl_combineIcons() 
        // First determine how big our composite icon will be; we need to know how wide & tall to make it.
        int totalWidth = (m_icons.length - 1) * ICON_PADDING; // Take into account the padding between icons
        int minHeight  = 0;
        for ( int i = 0; i < m_icons.length; ++i ) 
            totalWidth += m_icons[i].getIconWidth();
            if ( m_icons[i].getIconHeight() > minHeight ) 
                minHeight = m_icons[i].getIconHeight();
            
        

        // Create an image big enough and acquire the image canvas to draw on
        final BufferedImage compositeImage = new BufferedImage( totalWidth, minHeight, BufferedImage.TYPE_INT_ARGB );
        final Graphics      graphics       = compositeImage.createGraphics();

        // Iterate over the icons, painting each icon and adding some padding space between them
        int x = 0;
        for ( int i = 0; i < m_icons.length; ++i ) 
            final ImageIcon icon = m_icons[ i ];
            graphics.drawImage( icon.getImage(), x, 0, null );
            x += icon.getIconWidth() + ICON_PADDING;
        

        return new ImageIcon( compositeImage );
    

    /** Generates a hash that takes into account the number of icons this composition includes and the hash &
     *  order of those icons.
     *
     * @return A hash code.
     */
    @Override
    public int hashCode() 
        int weakHash = m_icons.length;
        for ( int i = 0; i < m_icons.length; ++i ) 
            weakHash += m_icons[i].hashCode() * (i + 1);
        
        return weakHash;
    

    /** Two instances are equal if and only if they include the same icons and they're in the same order.
     *
     * @param obj An object to check for equality with this.
     *
     * @return true if the two objects are equal, false otherwise.
     */
    @Override
    public boolean equals(final Object obj) 
        if ( !(obj instanceof CachedCompositeIcon) ) 
            return false;
        

        final CachedCompositeIcon other = (CachedCompositeIcon) obj;
        if ( m_icons.length != other.m_icons.length ) 
            return false;
        

        for ( int i = 0; i < m_icons.length; ++i ) 
            if ( m_icons[i].hashCode() != other.m_icons[i].hashCode() ) 
                return false;
            
        

        return true;
    

【参考方案4】：

是的，在容器标签中使用带有 BoxLayout 的嵌套 JLabel：

JLabel container = new JLabel();
container.setLayout(new BoxLayout(container, BoxLayout.X_AXIS));
JLabel icon1Label = new JLabel();
JLabel icon2Label = new JLabel();
icon1Label.setIcon(icon1);
icon2Label.setIcon(icon2);
container.add(icon1Label);
container.add(icon2Label);

【讨论】：

谢谢，成功了。我还添加了container.add(Box.createRigidArea(new Dimension(5,0))) 以在两个图标之间添加一些空间。