拖放后移动组件
我见过拖放代码 。
问题1：如何在丢弃图像后在丢弃的面板内移动图像（使用鼠标指针）。 （图像的目的地，我想要在哪里释放鼠标。然后改变位置（使用鼠标会更好。或使用按钮 – 但使用鼠标更好）
问题2：如何在结束后更改位置？
ps我想在这里图像到组件。
首先我拖放组件。 然后使用鼠标指针更改位置（移动它）。
这是代码：
import java.awt.BorderLayout; import java.awt.EventQueue; import java.awt.GridBagLayout; import java.awt.datatransfer.DataFlavor; import java.awt.datatransfer.Transferable; import java.awt.datatransfer.UnsupportedFlavorException; import java.awt.dnd.DnDConstants; import java.awt.dnd.DragGestureEvent; import java.awt.dnd.DragGestureListener; import java.awt.dnd.DragGestureRecognizer; import java.awt.dnd.DragSource; import java.awt.dnd.DragSourceDragEvent; import java.awt.dnd.DragSourceDropEvent; import java.awt.dnd.DragSourceEvent; import java.awt.dnd.DragSourceListener; import java.awt.dnd.DropTarget; import java.awt.dnd.DropTargetDragEvent; import java.awt.dnd.DropTargetDropEvent; import java.awt.dnd.DropTargetEvent; import java.awt.dnd.DropTargetListener; import java.io.IOException; import javax.swing.DefaultListModel; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JList; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; public class TestDnD { public static void main(String[] args) { new TestDnD(); } public TestDnD() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException ex) { } catch (InstantiationException ex) { } catch (IllegalAccessException ex) { } catch (UnsupportedLookAndFeelException ex) { } JFrame frame = new JFrame("Test"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); frame.add(new TestPane()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } public class TestPane extends JPanel { private JList list; public TestPane() { setLayout(new BorderLayout()); list = new JList(); DefaultListModel model = new DefaultListModel(); model.addElement(new User("Shaun")); model.addElement(new User("Andy")); model.addElement(new User("Luke")); model.addElement(new User("Han")); model.addElement(new User("Liea")); model.addElement(new User("Yoda")); list.setModel(model); add(new JScrollPane(list), BorderLayout.WEST); DragGestureRecognizer dgr = DragSource.getDefaultDragSource().createDefaultDragGestureRecognizer( list, DnDConstants.ACTION_COPY_OR_MOVE, new DragGestureHandler(list)); JPanel panel = new JPanel(new GridBagLayout()); add(panel); DropTarget dt = new DropTarget( panel, DnDConstants.ACTION_COPY_OR_MOVE, new DropTargetHandler(panel), true); } } public static class User { private String name; public User(String name) { this.name = name; } public String getName() { return name; } @Override public String toString() { return name; } } public static class UserTransferable implements Transferable { public static final DataFlavor USER_DATA_FLAVOR = new DataFlavor(User.class, "User"); private User user; public UserTransferable(User user) { this.user = user; } @Override public DataFlavor[] getTransferDataFlavors() { return new DataFlavor[]{USER_DATA_FLAVOR}; } @Override public boolean isDataFlavorSupported(DataFlavor flavor) { return USER_DATA_FLAVOR.equals(flavor); } @Override public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException { Object value = null; if (USER_DATA_FLAVOR.equals(flavor)) { value = user; } else { throw new UnsupportedFlavorException(flavor); } return value; } } protected class DragGestureHandler implements DragGestureListener { private JList list; public DragGestureHandler(JList list) { this.list = list; } @Override public void dragGestureRecognized(DragGestureEvent dge) { Object selectedValue = list.getSelectedValue(); if (selectedValue instanceof User) { User user = (User) selectedValue; Transferable t = new UserTransferable(user); DragSource ds = dge.getDragSource(); ds.startDrag(dge, null, t, new DragSourceHandler()); } } } protected class DragSourceHandler implements DragSourceListener { public void dragEnter(DragSourceDragEvent dsde) { } public void dragOver(DragSourceDragEvent dsde) { } public void dropActionChanged(DragSourceDragEvent dsde) { } public void dragExit(DragSourceEvent dse) { } public void dragDropEnd(DragSourceDropEvent dsde) { System.out.println("Drag ended..."); } } protected class DropTargetHandler implements DropTargetListener { private JPanel panel; public DropTargetHandler(JPanel panel) { this.panel = panel; } public void dragEnter(DropTargetDragEvent dtde) { if (dtde.getTransferable().isDataFlavorSupported(UserTransferable.USER_DATA_FLAVOR)) { System.out.println("Accept..."); dtde.acceptDrag(DnDConstants.ACTION_COPY_OR_MOVE); } else { System.out.println("Drag..."); dtde.rejectDrag(); } } public void dragOver(DropTargetDragEvent dtde) { } public void dropActionChanged(DropTargetDragEvent dtde) { } public void dragExit(DropTargetEvent dte) { } public void drop(DropTargetDropEvent dtde) { System.out.println("Dropped..."); if (dtde.getTransferable().isDataFlavorSupported(UserTransferable.USER_DATA_FLAVOR)) { Transferable t = dtde.getTransferable(); if (t.isDataFlavorSupported(UserTransferable.USER_DATA_FLAVOR)) { try { Object transferData = t.getTransferData(UserTransferable.USER_DATA_FLAVOR); if (transferData instanceof User) { User user = (User) transferData; dtde.acceptDrop(DnDConstants.ACTION_COPY_OR_MOVE); panel.add(new JLabel(user.getName())); panel.revalidate(); panel.repaint(); } else { dtde.rejectDrop(); } } catch (UnsupportedFlavorException ex) { ex.printStackTrace(); dtde.rejectDrop(); } catch (IOException ex) { ex.printStackTrace(); dtde.rejectDrop(); } } else { dtde.rejectDrop(); } } } } }
这是在两个类似窗格之间拖动图像的实现。
如果您要抛出不允许Component移动的限制，那么您将不得不确保源和目标容器知道如何处理拖放（并呈现结果）
这花费了4个小时，所以在你敲定更新请求之前，请确保你已经努力理解代码并实现了自己的更改
该实现将Image包装在DragImage类中，该类维护有关图像在其容器内的位置的信息，这用于生成拖动图像…
import java.awt.AlphaComposite; import java.awt.Color; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.Image; import java.awt.Point; import java.awt.Rectangle; import java.awt.datatransfer.DataFlavor; import java.awt.datatransfer.Transferable; import java.awt.datatransfer.UnsupportedFlavorException; import java.awt.dnd.DnDConstants; import java.awt.dnd.DragGestureEvent; import java.awt.dnd.DragGestureListener; import java.awt.dnd.DragGestureRecognizer; import java.awt.dnd.DragSource; import java.awt.dnd.DragSourceDragEvent; import java.awt.dnd.DragSourceDropEvent; import java.awt.dnd.DragSourceEvent; import java.awt.dnd.DragSourceListener; import java.awt.dnd.DropTarget; import java.awt.dnd.DropTargetDragEvent; import java.awt.dnd.DropTargetDropEvent; import java.awt.dnd.DropTargetEvent; import java.awt.dnd.DropTargetListener; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import javax.imageio.ImageIO; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; import javax.swing.border.EmptyBorder; import javax.swing.border.LineBorder; public class TestDnD { public static void main(String[] args) { new TestDnD(); } public TestDnD() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException ex) { } catch (InstantiationException ex) { } catch (IllegalAccessException ex) { } catch (UnsupportedLookAndFeelException ex) { } JFrame frame = new JFrame("Test"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new GridLayout(0, 2, 10, 10)); ((JComponent) frame.getContentPane()).setBorder(new EmptyBorder(10, 10, 10, 10)); BufferedImage img = ImageIO.read(new File("issue376.jpg")); ImagePane imagePane = new ImagePane(); imagePane.addImage(img); frame.add(imagePane); frame.add(new ImagePane()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } catch (IOException ex) { ex.printStackTrace(); System.exit(0); } } }); } public class ImagePane extends JPanel { private List images; private DragImages dropImages; private Point dragPoint; public ImagePane() { setBorder(new LineBorder(Color.GRAY)); images = new ArrayList<>(25); DragGestureRecognizer dgr = DragSource.getDefaultDragSource().createDefaultDragGestureRecognizer( this, DnDConstants.ACTION_COPY_OR_MOVE, new DragGestureHandler(this)); DropTarget dt = new DropTarget( this, DnDConstants.ACTION_COPY_OR_MOVE, new DropTargetHandler(this), true); } @Override public Dimension getPreferredSize() { return new Dimension(200, 200); } public DragImage getImageAt(Point p) { DragImage at = null; for (DragImage di : images) { if (di.contains(p)) { at = di; break; } } return at; } protected boolean contains(Image image) { boolean contains = false; for (DragImage di : images) { if (di.getImage() == image) { contains = true; break; } } return contains; } public void addImage(Image image) { if (image != null) { if (!contains(image)) { int x = (int) Math.round(Math.random() * getWidth()); int y = (int) Math.round(Math.random() * getHeight()); addImageAt(new Point(x, y), image); } } } public void addImageAt(Point p, Image image) { if (p != null && image != null) { if (!contains(image)) { DragImage di = new DragImage(image, p); images.add(di); repaint(); } } } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D) g.create(); for (DragImage di : images) { g2d.drawImage(di.getImage(), di.getLocation().x, di.getLocation().y, this); } if (dropImages != null) { g2d.setComposite(AlphaComposite.SrcOver.derive(0.5f)); Point offset = dropImages.getOffset(); for (DragImage di : dropImages.getImages()) { Point pp = new Point(dragPoint); pp.x -= offset.getX(); pp.y -= offset.getY(); g2d.drawImage(di.getImage(), pp.x, pp.y, this); } } g2d.dispose(); } public void removeImages(List list) { if (list != null && list.size() > 0) { for (Object obj : list) { if (obj instanceof DragImage) { removeImage((DragImage) obj); } } } } public void removeImage(DragImage img) { images.remove(img); repaint(); } protected void setDragImages(DragImages dragImages) { this.dropImages = dragImages; repaint(); } public void addImagesAt(Point location, List images) { if (images != null && images.size() > 0) { for (Object obj : images) { if (obj instanceof Image) { Image img = (Image) obj; addImageAt(location, img); location.x += 10; location.y += 10; if (location.x >= getWidth()) { location.x = 0; } if (location.y >= getHeight()) { location.y = 0; } } } } } protected void addImages(DragImages dragImages) { for (DragImage di : dragImages.getImages()) { images.add(di); } repaint(); } protected void addImagesAt(Point dropPoint, DragImages dragImages) { Point offset = dragImages.getOffset(); for (DragImage di : dragImages.getImages()) { Point p = di.getLocation(); px = dropPoint.x - offset.x; py = dropPoint.y - offset.y; images.add(di); } repaint(); } protected void setDragPoint(Point location) { dragPoint = location; repaint(); } } public static class ImageTransferable implements Transferable { public static final DataFlavor DRAG_IMAGE_DATA_FLAVOR = new DataFlavor(List.class, "Images"); private DragImages dragImages; public ImageTransferable(DragImages dragImages) { this.dragImages = dragImages; } @Override public DataFlavor[] getTransferDataFlavors() { return new DataFlavor[]{DRAG_IMAGE_DATA_FLAVOR}; } @Override public boolean isDataFlavorSupported(DataFlavor flavor) { return DRAG_IMAGE_DATA_FLAVOR.equals(flavor); } @Override public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException { return dragImages; } } public class DragImage { private Image image; private Point p; public DragImage(Image image, Point p) { this.image = image; this.p = p; } public Image getImage() { return image; } public Point getLocation() { return p; } public Dimension getSize() { return new Dimension(image.getWidth(null), image.getHeight(null)); } public boolean contains(Point p) { return new Rectangle(getLocation(), getSize()).contains(p); } } public class DragImages { private Point offset; private List images; public DragImages(Point offset, DragImage... images) { this.offset = offset; this.images = Arrays.asList(images); } public Point getOffset() { return offset; } public List getImages() { return images; } } protected class DragGestureHandler implements DragGestureListener { private ImagePane imagePane; public DragGestureHandler(ImagePane list) { this.imagePane = list; } @Override public void dragGestureRecognized(DragGestureEvent dge) { DragImage di = imagePane.getImageAt(dge.getDragOrigin()); if (di != null) { Point origin = dge.getDragOrigin(); Point p = new Point(); px = origin.x - di.getLocation().x; py = origin.y - di.getLocation().y; Transferable t = new ImageTransferable(new DragImages(p, di)); imagePane.removeImage(di); DragSource ds = dge.getDragSource(); ds.startDrag( dge, null, t, new DragSourceHandler(imagePane)); } } } protected class DragSourceHandler implements DragSourceListener { private ImagePane pane; public DragSourceHandler(ImagePane pane) { this.pane = pane; } public void dragEnter(DragSourceDragEvent dsde) { } public void dragOver(DragSourceDragEvent dsde) { pane.repaint(); } public void dropActionChanged(DragSourceDragEvent dsde) { } public void dragExit(DragSourceEvent dse) { } public void dragDropEnd(DragSourceDropEvent dsde) { if (!dsde.getDropSuccess()) { Transferable t = dsde.getDragSourceContext().getTransferable(); if (t != null) { try { Object transferData = t.getTransferData(ImageTransferable.DRAG_IMAGE_DATA_FLAVOR); if (transferData instanceof DragImages) { DragImages di = (DragImages) transferData; pane.addImages(di); } } catch (UnsupportedFlavorException | IOException ex) { ex.printStackTrace(); } } } } } protected class DropTargetHandler implements DropTargetListener { private ImagePane panel; public DropTargetHandler(ImagePane panel) { this.panel = panel; } public void dragEnter(DropTargetDragEvent dtde) { if (dtde.getTransferable().isDataFlavorSupported(ImageTransferable.DRAG_IMAGE_DATA_FLAVOR)) { dtde.acceptDrag(DnDConstants.ACTION_COPY_OR_MOVE); updateDragImages(dtde); } else { dtde.rejectDrag(); } } public void dragOver(DropTargetDragEvent dtde) { updateDragImages(dtde); panel.repaint(); } public void dropActionChanged(DropTargetDragEvent dtde) { } public void dragExit(DropTargetEvent dte) { panel.setDragImages(null); } public void drop(DropTargetDropEvent dtde) { panel.setDragImages(null); if (dtde.getTransferable().isDataFlavorSupported(ImageTransferable.DRAG_IMAGE_DATA_FLAVOR)) { Transferable t = dtde.getTransferable(); if (t.isDataFlavorSupported(ImageTransferable.DRAG_IMAGE_DATA_FLAVOR)) { try { Object transferData = t.getTransferData(ImageTransferable.DRAG_IMAGE_DATA_FLAVOR); if (transferData instanceof DragImages) { DragImages images = (DragImages) transferData; dtde.dropComplete(true); dtde.acceptDrop(DnDConstants.ACTION_COPY_OR_MOVE); panel.addImagesAt(dtde.getLocation(), images); } else { dtde.rejectDrop(); } } catch (UnsupportedFlavorException ex) { ex.printStackTrace(); dtde.rejectDrop(); } catch (IOException ex) { ex.printStackTrace(); dtde.rejectDrop(); } } else { dtde.rejectDrop(); } } } protected void updateDragImages(DropTargetDragEvent dtde) { panel.setDragImages(null); Transferable t = dtde.getTransferable(); if (t != null) { try { Object transferData = t.getTransferData(ImageTransferable.DRAG_IMAGE_DATA_FLAVOR); if (transferData instanceof DragImages) { panel.setDragPoint(dtde.getLocation()); panel.setDragImages((DragImages)transferData); } } catch (UnsupportedFlavorException | IOException ex) { ex.printStackTrace(); } } } } }