设置背景图，并在上面添加可随意拖动的图片标签

最近要通过java的swing组件实现一个功能：添加一张背景图片，之后在上面随意添加不同的可拖动的小图片标签，刚开始不太懂，绕了很大一个弯路，想着用JLayeredPane的分层去实现，但最终没能如愿，从头开始之后，思路一下清晰了起来，想到了一种非常简单的实现方式，这里分享一下代码：
只有一个类，复制粘贴之后，找几张图片，和类放在同一个目录下，在修改一下图片名称，直接运行就能看到效果了：

package testSwing;import java.awt.Dimension;import java.awt.Graphics;import java.awt.Image;import java.awt.Point;import javax.swing.BorderFactory;import javax.swing.ImageIcon;import javax.swing.JButton;import javax.swing.JFileChooser;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.SwingConstants;import java.awt.Toolkit;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.MouseAdapter;import java.awt.event.MouseEvent;import java.beans.PropertyChangeEvent;import java.beans.PropertyChangeListener;import java.io.File;public class ModuleAdd extends JFrame{//背景图片JPanel jpanel; ImageIcon image;ImageIcon icon;Image img;//int x, y;//鼠标双击时的坐标 ImageIcon markerIcon; //标签图标 //更改标签图片 private Point pressPoint; //press标签时的鼠标位 final int PREVIEW_SIZE = 100; JFrame jf = new JFrame("更改标签图片"); JButton button = new JButton(""); //以当前路径创建文件选择器 JFileChooser chooser = new JFileChooser("."); JLabel accessory = new JLabel(); public void changeMarker(){ chooser.setAccessory(accessory);//为文件选择器指定一个预览图片的附件组件 //设置预览图片组件的大小和边框 accessory.setPreferredSize(new Dimension(PREVIEW_SIZE, PREVIEW_SIZE)); accessory.setBorder(BorderFactory.createEtchedBorder()); //用于检测被选择文件的改变事件 chooser.addPropertyChangeListener(new PropertyChangeListener() { public void propertyChange(PropertyChangeEvent event) { //JFileChooser的被选文件已经发生了改变 if (event.getPropertyName() == JFileChooser.SELECTED_FILE_CHANGED_PROPERTY) { File f = (File) event.getNewValue(); //获取用户选择的新文件 if (f == null) { accessory.setIcon(null); return; } ImageIcon icon = new ImageIcon(f.getPath()); //将所文件读入ImageIcon对象中 //如果图像太大，则缩小它 if(icon.getIconWidth() > PREVIEW_SIZE) { icon = new ImageIcon(icon.getImage() .getScaledInstance(PREVIEW_SIZE, -1, Image.SCALE_DEFAULT)); } //改变accessory Label的图标 accessory.setIcon(icon); } } }); button.setToolTipText("选择标签"); button.setIcon(new ImageIcon(JFrameBackground.class.getResource("/testSwing/Browse-64.png"))); //为buttom增加事件 button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { int result = chooser.showDialog(jf , "打开"); //显示文件对话框 //如果用户选择了APPROVE（赞同）按钮，即打开，保存及其等效按钮 if(result == JFileChooser.APPROVE_OPTION) { String name = chooser.getSelectedFile().getPath(); markerIcon=new ImageIcon(name); //显示指定图片 } } }); } public void addMarker() {final JLabel lablel = new JLabel("");lablel.setHorizontalAlignment(SwingConstants.CENTER);lablel.setIcon(markerIcon);lablel.setBounds(x, y, 16, 16); jpanel.add(lablel); repaint(); //为添加的标签增加拖动事件 lablel.addMouseListener(new MouseAdapter(){@Overridepublic void mousePressed(MouseEvent e) {pressPoint = e.getPoint();}@Overridepublic void mouseReleased(MouseEvent e) {pressPoint = null;} }); lablel.addMouseMotionListener(new MouseAdapter(){@Overridepublic void mouseDragged(MouseEvent e) {Point nowPoint = e.getPoint(); //当前鼠标拖拽到的鼠标位置 int diffX = nowPoint.x - pressPoint.x; int diffY = nowPoint.y - pressPoint.y; /**移动**/ lablel.setLocation(lablel.getX()+diffX,lablel.getY()+diffY); System.out.println(lablel.getX()+" "+lablel.getY());} }); } public void ini() {jpanel.addMouseListener(new MouseAdapter() {public void mouseClicked(MouseEvent m) {if (m.getClickCount() == 2) {x = m.getPoint().x;y = m.getPoint().y;System.out.println("x:"+x+" y:"+y);addMarker();}}});}public ModuleAdd(){setIconImage(Toolkit.getDefaultToolkit().getImage(ModuleAdd.class.getResource("/testSwing/swingTest.jpg")));icon= new ImageIcon(SwingImgAdd.class.getResource("/testSwing/swingTest.jpg")); img = icon.getImage(); jpanel = new JPanel(){protected void paintComponent(Graphics g) { g.drawImage(img, 0, 0, icon.getIconWidth(), icon.getIconHeight(), icon.getImageObserver());}};jpanel.setPreferredSize(new Dimension(icon.getIconWidth(), icon.getIconHeight()));ini();changeMarker();setTitle("增加标签"); button.setBounds(0,20,98,41);getContentPane().add(button);getContentPane().add(new JScrollPane( jpanel));jpanel.setLayout(null);this.setSize(780,550);System.out.println(this.getSize()); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.setLocationRelativeTo(null); this.setVisible(true);}public static void main(String[] args) {new ModuleAdd();}}

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