右键单击以复制并粘贴Java

Question

我正在使用Netbeans开发将在Windows中使用的应用程序。我注意到我无法右键单击进行复制或粘贴。我怎样才能启用它？ （我使用的是基本的Swing控件，如JText和JTextArea。）

Answer 1

Why right click is not working on java application?

我不会创建新的复制，剪切，粘贴，撤消和选择所有操作，因为那些已经存在于每个组件的ActionMap中。我只是这样做：

 Action copyAction = textField.getActionMap().get("copy");
 Action cutAction = textField.getActionMap().get("cut");
 Action pasteAction = textField.getActionMap().get("paste");
 Action undoAction = textField.getActionMap().get("undo");
 Action selectAllAction = textField.getActionMap().get("selectAll");


 popup.add (undoAction);
 popup.addSeparator();
 popup.add (cutAction);
 popup.add (copyAction);
 popup.add (pasteAction);
 popup.addSeparator();
 popup.add (selectAllAction);

 return popup;

这样您就不会重新创建已编写的更多代码。除此之外，我会遵循这个例子。

Answer 2

对于你的评论，

它是否与操作系统交互？我想从我的Java应用程序中复制一些东西并粘贴在记事本上。

为什么不打扰用户手动复制粘贴，为什么不将textarea的内容写入文本文件？

Answer 3

final int colx;
final int rowy;
final String val1;

colx = CFDTable.getSelectedColumn();
rowy = CFDTable.getSelectedRow();

val1 = (String) CFDTable.getValueAt(rowy, colx);
JPopupMenu jPopupMenu = new javax.swing.JPopupMenu();
jPopupMenu.setName("jPopupMenu");
CFDTable.setComponentPopupMenu(jPopupMenu);
JMenuItem jMenuItem = new javax.swing.JMenuItem();
jMenuItem.setText("Copy"); // NOI18N
jMenuItem.setName("jMenuItem"); // NOI18N
jPopupMenu.add(jMenuItem);

jMenuItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
StringSelection entry = new StringSelection(val1);
Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
clipboard.setContents(entry, entry);
}
});

Answer 4

静态类可以立即将常规弹出菜单添加到文本字段中。

只需调用JTextFieldRegularPopupMenu.addTo（jTextFieldObj）;

import javax.swing.*;
import java.awt.event.ActionEvent;
import javax.swing.JPopupMenu;
import javax.swing.undo.*;


public class JTextFieldRegularPopupMenu {
    public static void addTo(JTextField txtField) 
    {
        JPopupMenu popup = new JPopupMenu();
        UndoManager undoManager = new UndoManager();
        txtField.getDocument().addUndoableEditListener(undoManager);

        Action undoAction = new AbstractAction("Undo") {
            @Override
            public void actionPerformed(ActionEvent ae) {
                if (undoManager.canUndo()) {
                    undoManager.undo();
                }
                else {
                    JOptionPane.showMessageDialog(null,
                            "Undoable: " + undoManager.canUndo() ,
                            "Undo Status", 
                            JOptionPane.INFORMATION_MESSAGE);
                }
            }
        };

       Action copyAction = new AbstractAction("Copy") {
            @Override
            public void actionPerformed(ActionEvent ae) {
                txtField.copy();
            }
        };

        Action cutAction = new AbstractAction("Cut") {
            @Override
            public void actionPerformed(ActionEvent ae) {
                txtField.cut();
            }
        };

        Action pasteAction = new AbstractAction("Paste") {
            @Override
            public void actionPerformed(ActionEvent ae) {
                txtField.paste();
            }
        };

        Action selectAllAction = new AbstractAction("Select All") {
            @Override
            public void actionPerformed(ActionEvent ae) {
                txtField.selectAll();
            }
        };

        popup.add (undoAction);
        popup.addSeparator();
        popup.add (cutAction);
        popup.add (copyAction);
        popup.add (pasteAction);
        popup.addSeparator();
        popup.add (selectAllAction);

       txtField.setComponentPopupMenu(popup);
    }
}

Answer 5

任何JTextComponent的完整工作模型，包括非功能性操作和在文本选择状态下启用/禁用菜单项。

    private JMenuItem composeMenuItemFromActionOfComponent(String actionTag, JComponent component, String text, String idTag){
    Action action = component.getActionMap().get(actionTag);
    JMenuItem menuItem = new JMenuItem(action);
    menuItem.setText(text);
    menuItem.putClientProperty("id",idTag);
    if(action == null)
        menuItem.setEnabled(false);
    return menuItem;
}
private void addTextMenuItems(JTextComponent textField){
    final JPopupMenu popup = new JPopupMenu();
    if(textField.isEditable()) {
        popup.add(composeMenuItemFromActionOfComponent("undo", textField, "Undo", "undo"));
        popup.addSeparator();
    }
    popup.add (composeMenuItemFromActionOfComponent(DefaultEditorKit.copyAction,textField,"Copy", "copy"));
    if(textField.isEditable()) {
        popup.add(composeMenuItemFromActionOfComponent(DefaultEditorKit.cutAction, textField, "Cut", "cut"));
        popup.add(composeMenuItemFromActionOfComponent(DefaultEditorKit.pasteAction, textField, "Paste", "paste"));
        popup.addSeparator();
    }
    popup.add (composeMenuItemFromActionOfComponent(DefaultEditorKit.selectAllAction,textField,"Select All", "select_all"));

    textField.addMouseListener(new MouseListener() {
        @Override
        public void mouseClicked(MouseEvent e) {}

        @Override
        public void mousePressed(MouseEvent e) {}

        @Override
        public void mouseReleased(MouseEvent e) {
            if(e.isPopupTrigger()) {
                boolean isTextSelected = textField.getSelectedText() != null;
                for(MenuElement element : popup.getSubElements()){
                    JMenuItem menuItem = ((JMenuItem) element);
                    if(menuItem.getAction() != null && menuItem.getAction().isEnabled()) {
                        if (isTextSelected){
                            menuItem.setEnabled(true);
                        }else if (!(menuItem.getClientProperty("id").equals("select_all")
                                || menuItem.getClientProperty("id").equals("undo")))
                            menuItem.setEnabled(false);
                    }
                    if(menuItem.getClientProperty("id").equals("paste")){
                        boolean isPastAvailable = false;
                        for(DataFlavor flavor : Toolkit.getDefaultToolkit().getSystemClipboard().getAvailableDataFlavors()){
                            if(flavor.getRepresentationClass() == String.class){
                                isPastAvailable = true;
                                break;
                            }
                        }
                        menuItem.setEnabled(isPastAvailable);
                    }

                }
                e.getComponent().requestFocus();
                popup.show(e.getComponent(), e.getX(), e.getY());
            }

        }

        @Override
        public void mouseEntered(MouseEvent e) {}

        @Override
        public void mouseExited(MouseEvent e) {}
    });
}