拖放两个图像并将它们放在同一JFrame中的两个不同的JButton中 [英] Drag two images and drop them in two different JButtons in the same JFrame
问题描述
我有一个代码，其中必须从桌面上拖动两个图像，然后将其拖放到两个可拖动按钮中的框架上.按钮已在框架上完成.但是在拖动图像时，只能将它们拖动到一个按钮上.图像不会被拖到另一幅图像上.我创建了一个 DragListener 类，其中使用了拖动方法，并创建了一个主类 DragInitialListener ，在该类中，我传递了 DragButton 类的对象，以便可以使用两个可拖动按钮被创建.我已经尝试了所有可能想到的方法，制作了两个 DragListener 类，以不同的方式传递了这些方法，但是只能将图像拖动到一个按钮中.我希望两个按钮都能够保存图像.请帮我.这是我到目前为止编写的代码:
I have a code in which I must drag two images from my desktop and drop it on a frame in two draggable buttons. The buttons have already been made on the frame. But while dragging the images, they can only be dragged to one button. The images don't get dragged to the other one. I have made a DragListener class where the dragging methods prevail and the main class DragInitialListener where I have passed objects of class DragButton so that two draggable buttons are created. I have tried everything I could think of, made two DragListener classes, passed the methods differently but the image could only be dragged in one button. I want both the buttons to be able to hold images. Please help me with it. Here's the code that I have made so far:
//这是主要的类
public class DragInitialListener extends javax.swing.JFrame {
private volatile int draggedAtX, draggedAtY;
public DragInitialListener() {
initComponents();
Droptargets();
Droptarget();
}
public void Droptarget()
{
DragListener d;
DragButton db = new DragButton();
db.setSize(170,140);
d= new DragListener(db);
DropTarget drop = new DropTarget(this,d);
this.getContentPane().add(db);
}
public void Droptargets()
{
DragListener dd;
DragButton db1 = new DragButton();
db1.setSize(170,140);
dd= new DragListener(db1);
DropTarget drop1 = new DropTarget(this,dd);
this.getContentPane().add(db1);
}
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 300, Short.MAX_VALUE)
);
pack();
}// </editor-fold>
public static void main(String args[]) {
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new DragInitialListener().setVisible(true);
}
});
}
// Variables declaration - do not modify
// End of variables declaration
}
//这是DragListener类
//This is the DragListener class
public class DragListener extends JButton implements DropTargetListener
{
JButton imagebutton = new JButton();
// JButton imagebutton1 = new JButton();
private volatile int draggedAtX, draggedAtY;
DragListener(JButton image) {
imagebutton=image;
}
@Override
public void dragEnter(DropTargetDragEvent dtde) {
}
@Override
public void dragOver(DropTargetDragEvent dtde) {
}
@Override
public void dropActionChanged(DropTargetDragEvent dtde) {
}
@Override
public void dragExit(DropTargetEvent dte) {
}
@Override
public void drop(DropTargetDropEvent ev) {
ev.acceptDrop(DnDConstants.ACTION_COPY);
Transferable t = ev.getTransferable();
//DropTarget test = (DropTarget) ev.getSource();
DataFlavor[] df= t.getTransferDataFlavors();
for(DataFlavor f:df)
{
try
{
if(f.isFlavorJavaFileListType())
{
List<File> files =(List<File>) t.getTransferData(f);
for(File file : files)
{
displayImage(file.getPath());
}
}
}
catch(Exception ex)
{
JOptionPane.showMessageDialog(null, ex);
}
}
}
private void displayImage(String path)
{
BufferedImage img = null;
try
{
img =ImageIO.read(new File(path));
}
catch(Exception e)
{
}
ImageIcon icon = new ImageIcon(img);
imagebutton.setIcon(icon);
}
}
推荐答案
从简单开始，只用一个按钮即可工作，如果可以工作一个，则可以工作100个.
Start simple, get one button to work, if you can get one to work, you can get 100 to work
这是一个非常简单的示例，它利用了传输API，因为您实际上只关心拖放而不是拖动
This is a very simple example, which makes use of the transfer API, because you really only care about dropping and not dragging
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.io.File;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.TransferHandler;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
JButton btn = new JButton("Drop here");
btn.setVerticalTextPosition(JButton.BOTTOM);
btn.setHorizontalTextPosition(JButton.CENTER);
btn.setTransferHandler(new ImageTransferHandler());
add(btn);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
}
public static class ImageTransferHandler extends TransferHandler {
public static final DataFlavor[] SUPPORTED_DATA_FLAVORS = new DataFlavor[]{
DataFlavor.javaFileListFlavor,
DataFlavor.imageFlavor
};
@Override
public boolean canImport(TransferHandler.TransferSupport support) {
boolean canImport = false;
for (DataFlavor flavor : SUPPORTED_DATA_FLAVORS) {
if (support.isDataFlavorSupported(flavor)) {
canImport = true;
break;
}
}
return canImport;
}
@Override
public boolean importData(TransferHandler.TransferSupport support) {
boolean accept = false;
if (canImport(support)) {
try {
Transferable t = support.getTransferable();
Component component = support.getComponent();
if (component instanceof JButton) {
Image image = null;
if (support.isDataFlavorSupported(DataFlavor.imageFlavor)) {
image = (Image) t.getTransferData(DataFlavor.imageFlavor);
} else if (support.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
List files = (List) t.getTransferData(DataFlavor.javaFileListFlavor);
if (files.size() > 0) {
image = ImageIO.read((File) files.get(0));
}
}
ImageIcon icon = null;
if (image != null) {
icon = new ImageIcon(image);
}
((JButton) component).setIcon(icon);
accept = true;
}
} catch (Exception exp) {
exp.printStackTrace();
}
}
return accept;
}
}
}
因此，通过不执行任何操作，然后更改布局并使用复制按钮
So, by doing nothing more then changing the layout and replicating the button using
public TestPane() {
setLayout(new GridLayout(5, 5));
for (int index = 0; index < 5 * 5; index++) {
JButton btn = new JButton("Drop here");
btn.setVerticalTextPosition(JButton.BOTTOM);
btn.setHorizontalTextPosition(JButton.CENTER);
btn.setTransferHandler(new ImageTransferHandler());
add(btn);
}
}
我能够实现...
因此，显然我可能是误解了这个问题，而不是第一次.根据对我的解释，您可能想要拖动多个图像并将其应用于按钮.令人惊讶的是，该过程变化不大.
So apparently I might have misunderstood the question, not the first time. From what's been explained to me, you might want to drag multiple images and have them applied to the buttons. Surprising, the process doesn't change that much.
在此示例中，我将 TransferHandler 应用于 JPanel 而不是按钮，并向其提供了我要更新的按钮.您可以轻松地对此进行更新，使其具有可变数量的按钮，但是我从两个开始.
In this example, I've applied the TransferHandler to the JPanel instead of the button and supplied it the buttons I want updated. You could easily update this to have a variable number of buttons, but I've started with two.
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.io.File;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.TransferHandler;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
JButton left = makeButton("Left");
JButton right = makeButton("Right");
add(left);
add(right);
setTransferHandler(new ImageTransferHandler(left, right));
}
protected JButton makeButton(String text) {
JButton btn = new JButton(text);
btn.setVerticalTextPosition(JButton.BOTTOM);
btn.setHorizontalTextPosition(JButton.CENTER);
return btn;
}
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
}
public static class ImageTransferHandler extends TransferHandler {
public static final DataFlavor[] SUPPORTED_DATA_FLAVORS = new DataFlavor[]{
DataFlavor.javaFileListFlavor,};
private JButton left, right;
public ImageTransferHandler(JButton left, JButton right) {
this.left = left;
this.right = right;
}
@Override
public boolean canImport(TransferHandler.TransferSupport support) {
boolean canImport = false;
for (DataFlavor flavor : SUPPORTED_DATA_FLAVORS) {
if (support.isDataFlavorSupported(flavor)) {
canImport = true;
break;
}
}
return canImport;
}
@Override
public boolean importData(TransferHandler.TransferSupport support) {
boolean accept = false;
if (canImport(support)) {
try {
Transferable t = support.getTransferable();
Image image = null;
if (support.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
List files = (List) t.getTransferData(DataFlavor.javaFileListFlavor);
JButton buttons[] = new JButton[]{left, right};
for (int index = 0; index < Math.min(files.size(), 2); index++) {
if (files.size() > 0) {
image = ImageIO.read((File) files.get(index));
ImageIcon icon = null;
if (image != null) {
icon = new ImageIcon(image);
}
buttons[index].setIcon(icon);
}
}
accept = true;
}
} catch (Exception exp) {
exp.printStackTrace();
}
}
return accept;
}
}
}
现在，您将需要定义自己的规则，例如，当用户仅拖动单个图像时会发生什么?您是否每次都将其应用于第一个按钮(如我所使用的那样)，还是尝试找到没有图像的按钮并对其进行更新?如果所有按钮都带有图像，该怎么办?那要去哪里呢?
Now, there are rules you will need to define yourself, for example, what happens when the user only drags a single image? Do you apply it to the first button (as I have) every time, or do you try and find the button without an image and update it? What happens if all the buttons have images? Where does it go then?
您拒绝包含2张以上图片的拖动吗?
Do you reject drags with more than 2 images?
这篇关于拖放两个图像并将它们放在同一JFrame中的两个不同的JButton中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
