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我之前也发布过这个问题，但是这次我只添加了必需和必要的代码，尽管代码有点冗长。 我想在Jlabel中加载图像，然后在用户单击下一个按钮时更改图像之后。当用户想要移动或缩放图像时，只需选择图像边缘即可轻松完成，但不起作用。 除了缩放和移动图像，所有问题都解决了。如何通过拖动边缘来移动和缩放图像？
我的代码：
public class CopyOfPictureEditor extends JFrame
{
private static final long serialVersionUID = 6676383931562999417L;
String[] validpicturetypes = {"png", "jpg", "jpeg", "gif"};
Stack<File> pictures ;
JLabel label = new JLabel();
BufferedImage a = null;
JPanel panel = new JPanel();
public CopyOfPictureEditor()
{
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}
catch(Exception e)
{
e.printStackTrace();
}
JMenuBar menubar = new JMenuBar();
JMenu toolsmenu = new JMenu(" File ");
final File dir = new File("");
final JFileChooser file;
file = new JFileChooser();
file.setCurrentDirectory(dir);
file.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
file.showOpenDialog(panel);
String path = file.getSelectedFile().getAbsolutePath();
System.out.println(path);
pictures= getFilesInFolder(path.toString());
JButton NEXT = new JButton("");
NEXT.setToolTipText("Next Image");
Image imgn = null;
try
{
imgn = ImageIO.read(getClass().getResource("/images/next12.png"));
}catch (IOException e) {
e.printStackTrace();
}
NEXT.setIcon(new ImageIcon(imgn));
JPanel buttonPane = new JPanel();
buttonPane.add(Box.createRigidArea(new Dimension(250,0)));
buttonPane.add(Box.createRigidArea(new Dimension(250,0)));
NEXT.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
nextImage();
}
});
buttonPane.add(NEXT);
getContentPane().add(buttonPane, BorderLayout.SOUTH);
setJMenuBar(menubar);
menubar.add(toolsmenu);
panel.add(label,BorderLayout.CENTER);
add(panel);
setTitle("Aero Picture Editor");
setVisible(true);
setPreferredSize(getPreferredSize());
setLocation(0,0);
label.addMouseListenet(new MouseHandler());
label.addMouseMotionListenet(new MouseHandler());
}
public Stack<File> getFilesInFolder(String startPath){
File startFolder = new File(startPath);
Stack<File> picturestack = new Stack<File>();
String extension;
int dotindex;
for (File file : startFolder.listFiles()) {
extension = "";
dotindex = file.getName().lastIndexOf('.');
if (dotindex > 0) {
extension = file.getName().substring(dotindex + 1);
for (String filetype : validpicturetypes){
if (extension.equals(filetype)) {
picturestack.add(file);
}
}
}
}
return picturestack;
}
public void nextImage() {
String p;
File f;
try{
f= pictures.pop().getAbsoluteFile();
a=ImageIO.read(f);
p = f.getPath();
System.out.println(p);
} catch (IOException e1) {
e1.printStackTrace();
}
ImageIcon image = new ImageIcon(a);
label.setIcon(image);
repaint();
}
protected void paintComponent(Graphics g)
{
super.paintComponents(g);
Graphics2D g2d = (Graphics2D) g.create();
int x = (getWidth() - a.getWidth())/2;
int y = (getHeight() - a.getHeight())/2;
AffineTransform at = new AffineTransform();
at.translate(x, y);
g2d.setTransform(at);
g2d.drawImage(a, 0, 0, this);
g2d.dispose();
}
public enum MouseAction {
Move(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR)),
ResizeSouth(Cursor.getPredefinedCursor(Cursor.S_RESIZE_CURSOR)),
ResizeNorth(Cursor.getPredefinedCursor(Cursor.N_RESIZE_CURSOR)),
ResizeEast(Cursor.getPredefinedCursor(Cursor.E_RESIZE_CURSOR)),
ResizeWest(Cursor.getPredefinedCursor(Cursor.W_RESIZE_CURSOR)),
ResizeNorthEast(Cursor.getPredefinedCursor(Cursor.NE_RESIZE_CURSOR)),
ResizeNorthWest(Cursor.getPredefinedCursor(Cursor.NW_RESIZE_CURSOR)),
ResizeSouthEast(Cursor.getPredefinedCursor(Cursor.SE_RESIZE_CURSOR)),
ResizeSouthWest(Cursor.getPredefinedCursor(Cursor.SW_RESIZE_CURSOR));
private Cursor cursor;
private MouseAction(Cursor cursor) {
this.cursor = cursor;
}
public Cursor getCursor() {
return cursor;
}
}
public class MouseHandler extends MouseAdapter
{
private MouseAction action;
private Point clickPoint;
private boolean ignoreMoves;
protected void updateAction(MouseEvent e) {
int x = e.getX();
int y = e.getY();
int width = getWidth();
int height = getHeight();
if (x < 10 && y < 10) {
action = MouseAction.ResizeNorthWest;
} else if (x > width - 10 && y < 10) {
action = MouseAction.ResizeNorthWest;
} else if (y < 10) {
action = MouseAction.ResizeNorth;
} else if (x < 10 && y > height - 10) {
action = MouseAction.ResizeSouthWest;
} else if (x > width - 10 && y > height - 10) {
action = MouseAction.ResizeSouthEast;
} else if (y > height - 10) {
action = MouseAction.ResizeSouth;
} else if (x < 10) {
action = MouseAction.ResizeWest;
} else if (x > width - 10) {
action = MouseAction.ResizeEast;
} else {
action = MouseAction.Move;
} setCursor(action.getCursor());
}
@Override
public void mouseMoved(MouseEvent e) {
if (!ignoreMoves)
{
updateAction(e);
}
}
@Override
public void mousePressed(MouseEvent e) {
updateAction(e);
ignoreMoves = true;
clickPoint = e.getPoint();
repaint();
System.out.println(e.getX());
System.out.println(e.getY());*/
}
@Override
public void mouseReleased(MouseEvent e) {
clickPoint = null;
ignoreMoves = false;
}
@Override
public void mouseDragged(MouseEvent e) {
switch (action) {
case Move: {
Point p = e.getPoint();
p.x -= clickPoint.x;
p=SwingUtilities.convertPoint(label, p, null);
setLocation(p);
}
break;
case ResizeWest: {
Point p = e.getPoint();
int xDelta = p.x - clickPoint.x;
int width = getWidth() - xDelta;
int x = getX() + xDelta;
setSize(width, getHeight());
setLocation(x, getY());
revalidate();
}
break;
case ResizeEast: {
Point p = e.getPoint();
int xDelta = p.x - clickPoint.x;
int width = getWidth() + xDelta;
setSize(width, getHeight());
revalidate();
clickPoint = p;
}
break;
case ResizeNorth: {
Point p = e.getPoint();
int yDelta = p.y - clickPoint.y;
int height = getHeight() - yDelta;
int y = getY() + yDelta;
setSize(getWidth(), height);
setLocation(getX(), y);
revalidate();
}
break;
case ResizeSouth: {
Point p = e.getPoint();
int yDelta = p.y - clickPoint.y;
int height = getHeight() + yDelta;
setSize(getWidth(), height);
revalidate();
clickPoint = p;
}
break;
}
}
@Override
public void mouseExited(MouseEvent e)
{
}
}
}
你有没有可以编译的代码示例？你看到什么错误？ – Robert
@Robert - 没有先生，没有错误，当我实现这个代码时，整个窗口被拖拽，我无法通过选择边缘来拖动或缩放图像。 –
@ user2659972停止发布有关同一主题的问题，并做其他人已经多次询问的问题，提供[SSCCE]（http://sscce.org）。 –