swing图片显示

Question

我想实现：选择图片然后在swing中显示出来，显示大小随图片大小改变而改变。

Answer 1

在MenuItem里设置图片，显示大小随图片大小改变而改变
我试了，好使，其他控件里不知道行不行

Answer 2

给个参考吧
import   java.awt.Graphics;   
  import   java.awt.Image;   
  import   java.awt.Insets;   
  import   java.awt.image.BufferedImage;   
    
  import   javax.imageio.ImageIO;   
  import   javax.swing.*;   
  import   javax.swing.plaf.MenuItemUI;   
  import   javax.swing.plaf.basic.BasicPopupMenuUI;   
    
  public   class   BackgroundImgMenu   extends   JMenu   
  {   
  private   Image   bgImg;   
    
  public   BackgroundImgMenu(String   text,   Image   bgImg)   
  {   
  super(text);   
  this.bgImg   =   bgImg;   
  }   
    
  @Override   
  public   void   updateUI()   
  {   
          setUI((MenuItemUI)UIManager.getUI(this));   
    
          if   (getPopupMenu()   !=   null   )   
          {   
          getPopupMenu().setUI(new   PopupMenuUI());   
          }   
  }   
    
  @Override   
  public   JMenuItem   add(JMenuItem   menuItem)   
  {   
  menuItem.setOpaque(false);   
  return   super.add(menuItem);   
  }   
    
  private   class   PopupMenuUI   extends   BasicPopupMenuUI   
  {   
  @Override   
  public   void   paint(Graphics   g,   JComponent   c)   
  {   
  super.paint(g,   c);   
  Insets   insets   =   c.getInsets();   
    
  g.drawImage(bgImg,   insets.left,   insets.top,     
  c.getWidth()   -   insets.left   -   insets.right,   
  c.getHeight()   -   insets.top   -   insets.bottom,   c);   
  }   
  }   
    
  public   static   void   main(String[]   args)   throws   Exception   
  {   
  UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());   
    
  BufferedImage   img   =   ImageIO.read(BackgroundImgMenu.class.getResource("menubg.png"));   
    
  JMenuBar   menubar   =   new   JMenuBar();   
  JMenu   fileMenu   =   new   BackgroundImgMenu("File",   img);   
  JMenu   editMenu   =   new   BackgroundImgMenu("Edit",   img);   
  JMenu   editSubMenu   =   new   BackgroundImgMenu("SubMenu",   img);   
    
  editSubMenu.add(new   JMenuItem("SubMenuItem-1"));   
  editSubMenu.add(new   JMenuItem("SubMenuItem-2"));   
  editSubMenu.add(new   JMenuItem("SubMenuItem-3"));   
    
  fileMenu.add(new   JMenuItem("Open"));   
  fileMenu.add(new   JMenuItem("Save"));   
  fileMenu.add(new   JCheckBoxMenuItem("CheckboxMenuItem"));   
  fileMenu.add(new   JRadioButtonMenuItem("RadioButtonMenuItem"));   
  fileMenu.addSeparator();   
  fileMenu.add(new   JMenuItem("Exit"));   
    
  editMenu.add(new   JMenuItem("Copy"));   
  editMenu.add(new   JMenuItem("Paste"));   
  editMenu.add(new   JMenuItem("Cut"));   
  editMenu.add(editSubMenu);   
    
  menubar.add(fileMenu);   
  menubar.add(editMenu);   
    
  JFrame   f   =   new   JFrame("带背景图片的菜单");   
  f.setJMenuBar(menubar);   
  f.setSize(400,   400);   
  f.setLocationRelativeTo(null);   
  f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   
  f.setVisible(true); }   
  }   
  

Answer 3

import java.util.Locale;
import java.util.ResourceBundle;import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;import com.nec.zw.excise.common.IconFactory;
import com.nec.zw.excise.common.ProgrammeConstant;public class CopyOfIconMenuExample extends JMenuBar {    /**
     * serialVersionUID
     */
    private static final long serialVersionUID = 6104121891993446467L;    private static final String DFAULT_RESOURCE_BASE_NAME = "com/nec/zw/resource";    private static final String DEFAULT_LANGUAGE = "";
    
    /**
     * IconMenuExampleのプロセスアイコンパス
     */
    public static final String PROGRAMMECONSTANT_PROCESS_ICON_PATH = "PROCESS_ICON_PATH";    /**
     * IconMenuExampleの成果物アイコンパス
     */
    public static final String PROGRAMMECONSTANT_FUNCTION_ICON_PATH = "FUNCTION_ICON_PATH";    /**
     * IconMenuExampleのリソースアイコンパス
     */
    public static final String PROGRAMMECONSTANT_RESOURCE_ICON_PATH = "RESOURCE_ICON_PATH";    /**
     * IconMenuExampleのプロセス項目名
     */
    public static final String PROGRAMMECONSTANT_ITEM_NAME_PROCESS = "ITEM_NAME_PROCESS";    /**
     * IconMenuExampleのプロセス項目名
     */
    public static final String PROGRAMMECONSTANT_ITEM_NAME_FUNCTION = "ITEM_NAME_FUNCTION";    /**
     * IconMenuExampleのプロセス項目名
     */
    public static final String PROGRAMMECONSTANT_ITEM_NAME_RESOURCE = "ITEM_NAME_RESOURCE";    public CopyOfIconMenuExample() {
        this.add(this.buildMenu());
    }    private JMenu buildMenu() {
        String displayName = this.getResourceContent(ProgrammeConstant.PROGRAMMECONSTANT_MENU_NAME);
        JMenu menu = new JMenu(displayName);        this.buildMenuItem(
            CopyOfIconMenuExample.PROGRAMMECONSTANT_ITEM_NAME_PROCESS,
            CopyOfIconMenuExample.PROGRAMMECONSTANT_PROCESS_ICON_PATH,
            menu);
        this.buildMenuItem(
            CopyOfIconMenuExample.PROGRAMMECONSTANT_ITEM_NAME_FUNCTION,
            CopyOfIconMenuExample.PROGRAMMECONSTANT_FUNCTION_ICON_PATH,
            menu);
        this.buildMenuItem(
            CopyOfIconMenuExample.PROGRAMMECONSTANT_ITEM_NAME_RESOURCE,
            CopyOfIconMenuExample.PROGRAMMECONSTANT_RESOURCE_ICON_PATH,
            menu);        return menu;
    }    private void buildMenuItem(String nameKey, String iconKey, JMenu menu) {
        IconFactory iconFactory = IconFactory.getInstance();
        String name = this.getResourceContent(nameKey);
        String iconpath = this.getResourceContent(iconKey);
        menu.add(new JMenuItem(name, iconFactory.getIcon(iconpath)));
    }    private String getResourceContent(String iconKey) {
        return this.getResourceBundle().getString(iconKey);
    }    private ResourceBundle getResourceBundle() {
        return ResourceBundle.getBundle(
            CopyOfIconMenuExample.DFAULT_RESOURCE_BASE_NAME,
            new Locale(CopyOfIconMenuExample.DEFAULT_LANGUAGE));
    }    /**
     * @param args
     */
    public static void main(String[] args) {
        JFrame frame = new JFrame("IntroIconMenu");
        frame.setJMenuBar(new CopyOfIconMenuExample());
        frame.setVisible(true);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}
资源文件：
<!--IconMenuExampleResource-->
IconMenuExample.frame.title=IconMenuExampleMENU_NAME=IconMenu
ITEM_NAME_PROCESS=Process
ITEM_NAME_FUNCTION=Function
ITEM_NAME_RESOURCE=ResourcePROCESS_ICON_PATH=/icons/process.gif
FUNCTION_ICON_PATH=/icons/function.gif
RESOURCE_ICON_PATH=/icons/resource.gif
再建个Icons包，放几个icon

Answer 4

好像代码没有摘干净
import java.util.HashMap;
import java.util.Map;import javax.swing.Icon;
import javax.swing.ImageIcon;public class IconFactory {    /**
     * アイコンのMap
     */
    private final Map<String, Icon> iconMap = new HashMap<String, Icon>();    private static IconFactory factory = null;    public static IconFactory getInstance() {
        if (IconFactory.factory != null) {
            return IconFactory.factory;
        }
        return new IconFactory();
    }    public Icon getIcon(String iconPath) {
        Icon result = this.iconMap.get(iconPath);
        if (result == null) {
            try {
                result = new ImageIcon(this.getClass().getResource(iconPath));
            } catch (java.lang.NullPointerException e) {
                e.printStackTrace();
                return null;
            }
            this.iconMap.put(iconPath, result);
        }
        return result;
    }
}import java.util.Locale;
import java.util.ResourceBundle;import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;import com.nec.zw.excise.common.IconFactory;public class CopyOfIconMenuExample extends JMenuBar {    /**
     * serialVersionUID
     */
    private static final long serialVersionUID = 6104121891993446467L;    private static final String DFAULT_RESOURCE_BASE_NAME = "com/nec/zw/resource";    private static final String DEFAULT_LANGUAGE = "";    /**
     * IconMenuExampleのプロセスアイコンパス
     */
    public static final String PROGRAMMECONSTANT_PROCESS_ICON_PATH = "PROCESS_ICON_PATH";    /**
     * IconMenuExampleの成果物アイコンパス
     */
    public static final String PROGRAMMECONSTANT_FUNCTION_ICON_PATH = "FUNCTION_ICON_PATH";    /**
     * IconMenuExampleのリソースアイコンパス
     */
    public static final String PROGRAMMECONSTANT_RESOURCE_ICON_PATH = "RESOURCE_ICON_PATH";    /**
     * IconMenuExampleのプロセス項目名
     */
    public static final String PROGRAMMECONSTANT_ITEM_NAME_PROCESS = "ITEM_NAME_PROCESS";    /**
     * IconMenuExampleのプロセス項目名
     */
    public static final String PROGRAMMECONSTANT_ITEM_NAME_FUNCTION = "ITEM_NAME_FUNCTION";    /**
     * IconMenuExampleのプロセス項目名
     */
    public static final String PROGRAMMECONSTANT_ITEM_NAME_RESOURCE = "ITEM_NAME_RESOURCE";    /**
     * IconMenuExampleのメニュー名
     */
    public static final String PROGRAMMECONSTANT_MENU_NAME = "MENU_NAME";    public CopyOfIconMenuExample() {
        this.add(this.buildMenu());
    }    private JMenu buildMenu() {
        String displayName =
                this.getResourceContent(CopyOfIconMenuExample.PROGRAMMECONSTANT_MENU_NAME);
        JMenu menu = new JMenu(displayName);        this.buildMenuItem(
            CopyOfIconMenuExample.PROGRAMMECONSTANT_ITEM_NAME_PROCESS,
            CopyOfIconMenuExample.PROGRAMMECONSTANT_PROCESS_ICON_PATH,
            menu);
        this.buildMenuItem(
            CopyOfIconMenuExample.PROGRAMMECONSTANT_ITEM_NAME_FUNCTION,
            CopyOfIconMenuExample.PROGRAMMECONSTANT_FUNCTION_ICON_PATH,
            menu);
        this.buildMenuItem(
            CopyOfIconMenuExample.PROGRAMMECONSTANT_ITEM_NAME_RESOURCE,
            CopyOfIconMenuExample.PROGRAMMECONSTANT_RESOURCE_ICON_PATH,
            menu);        return menu;
    }    private void buildMenuItem(String nameKey, String iconKey, JMenu menu) {
        IconFactory iconFactory = IconFactory.getInstance();
        String name = this.getResourceContent(nameKey);
        String iconpath = this.getResourceContent(iconKey);
        menu.add(new JMenuItem(name, iconFactory.getIcon(iconpath)));
    }    private String getResourceContent(String iconKey) {
        return this.getResourceBundle().getString(iconKey);
    }    private ResourceBundle getResourceBundle() {
        return ResourceBundle.getBundle(
            CopyOfIconMenuExample.DFAULT_RESOURCE_BASE_NAME,
            new Locale(CopyOfIconMenuExample.DEFAULT_LANGUAGE));
    }    /**
     * @param args
     */
    public static void main(String[] args) {
        JFrame frame = new JFrame("IntroIconMenu");
        frame.setJMenuBar(new CopyOfIconMenuExample());
        frame.setVisible(true);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}
不摘代码类太多了 呵呵