如何将外部图像放入Java应用程序

Question

我希望将一个图像从我的桌面拖放到我的JPanel/Jframe上，然后能够将该图像存储到一个BufferedImage对象中，并对其执行id喜欢的操作

有没有办法用MouseListener做到这一点？

这是一个虚构的完美世界的例子，我可以在其中做到这一点

    Jframe jframe = new Jframe();
    //set up jframe bla bla bla
    
    MouseListener ml = new MouseListener(){
       mouseRealeased(MouseEvent e){
            //get droped thing from e
            if(check if dropped thing is an image){
                this.myImageField = (BufferedImage)droppedThing;
            }
       }
    }        
    jframe.addMouseListener(ml); 

我希望你能明白。不是在寻找超复杂的东西。我是个笨蛋，尽量简单谢谢：）

Answer 1

import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.UIManager;

public class FileDrag {

    public static void main(String[] args) {
        new FileDrag();
    }

    public class FilePane extends JLayeredPane {

        public FilePane() {
            File[] images = new File("C:\\hold\\thumbnails").listFiles(new FileFilter() {
                @Override
                public boolean accept(File pathname) {
                    String name = pathname.getName().toLowerCase();
                    return name.endsWith(".png") || 
                                    name.endsWith(".jpg") || 
                                    name.endsWith(".bmp") ||
                                    name.endsWith(".gif");
                }
            });

            int x = 0;
            int y = 0;
            for (File imgFile : images) {

                try {
                    BufferedImage img = ImageIO.read(imgFile);
                    JLabel label = new JLabel(new ImageIcon(img));
                    label.setSize(label.getPreferredSize());
                    label.setLocation(x, y);
                    MouseHandler mh  = new MouseHandler();
                    label.addMouseListener(mh);
                    label.addMouseMotionListener(mh);
                    add(label);
                    x += 20;
                    y += 20;
                } catch (IOException exp) {
                    exp.printStackTrace();
                }
            }
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(800, 800);
        }

        public class MouseHandler extends MouseAdapter {

            private Point offset;

            @Override
            public void mousePressed(MouseEvent e) {
                JLabel label = (JLabel) e.getComponent();
                moveToFront(label);
                offset = e.getPoint();
            }

            @Override
            public void mouseDragged(MouseEvent e) {
                int x = e.getPoint().x - offset.x;
                int y = e.getPoint().y - offset.y;
                Component component = e.getComponent();
                Point location = component.getLocation();
                location.x += x;
                location.y += y;
                component.setLocation(location);
            }
        }
    }
}

您还可以参考如何在Java GUI中使用鼠标光标拖动图像？