为什么右键单击不适用于java应用程序？

Question

我做了一个基于Java Swing的应用程序.
在我的应用程序中,如果我点击JFrame上的任何地方或任何东西,那么我的右键单击不起作用？
我没有设置那样的东西..那为什么不工作？

基本上我的键盘没有工作然后我尝试复制 - 使用鼠标粘贴数据然后,我来了解...我的右键单击不适用于我的应用程序的任何区域...

Answer 1

你的右键单击工作得很好 - 在Swing中,没有获得你在其他应用程序中习惯的上下文菜单是正常的.如果您想要一个右键单击的弹出菜单,例如剪切/复制/粘贴操作 - 您必须自己实现它.我在我的应用中使用了类似的东西:

public class ContextMenuMouseListener extends MouseAdapter {
    private JPopupMenu popup = new JPopupMenu();

    private Action cutAction;
    private Action copyAction;
    private Action pasteAction;
    private Action undoAction;
    private Action selectAllAction;

    private JTextComponent textComponent;
    private String savedString = "";
    private Actions lastActionSelected;

    private enum Actions { UNDO, CUT, COPY, PASTE, SELECT_ALL };

    public ContextMenuMouseListener() {
        undoAction = new AbstractAction("Undo") {

            @Override
            public void actionPerformed(ActionEvent ae) {
                    textComponent.setText("");
                    textComponent.replaceSelection(savedString);

                    lastActionSelected = Actions.UNDO;
            }
        };

        popup.add(undoAction);
        popup.addSeparator();

        cutAction = new AbstractAction("Cut") {

            @Override
            public void actionPerformed(ActionEvent ae) {
                lastActionSelected = Actions.CUT;
                savedString = textComponent.getText();
                textComponent.cut();
            }
        };

        popup.add(cutAction);

        copyAction = new AbstractAction("Copy") {

            @Override
            public void actionPerformed(ActionEvent ae) {
                lastActionSelected = Actions.COPY;
                textComponent.copy();
            }
        };

        popup.add(copyAction);

        pasteAction = new AbstractAction("Paste") {

            @Override
            public void actionPerformed(ActionEvent ae) {
                lastActionSelected = Actions.PASTE;
                savedString = textComponent.getText();
                textComponent.paste();
            }
        };

        popup.add(pasteAction);
        popup.addSeparator();

        selectAllAction = new AbstractAction("Select All") {

            @Override
            public void actionPerformed(ActionEvent ae) {
                lastActionSelected = Actions.SELECT_ALL;
                textComponent.selectAll();
            }
        };

        popup.add(selectAllAction);
    }

    @Override
    public void mouseClicked(MouseEvent e) {
        if (e.getModifiers() == InputEvent.BUTTON3_MASK) {
            if (!(e.getSource() instanceof JTextComponent)) {
                return;
            }

            textComponent = (JTextComponent) e.getSource();
            textComponent.requestFocus();

            boolean enabled = textComponent.isEnabled();
            boolean editable = textComponent.isEditable();
            boolean nonempty = !(textComponent.getText() == null || textComponent.getText().equals(""));
            boolean marked = textComponent.getSelectedText() != null;

            boolean pasteAvailable = Toolkit.getDefaultToolkit().getSystemClipboard().getContents(null).isDataFlavorSupported(DataFlavor.stringFlavor);

            undoAction.setEnabled(enabled && editable && (lastActionSelected == Actions.CUT || lastActionSelected == Actions.PASTE));
            cutAction.setEnabled(enabled && editable && marked);
            copyAction.setEnabled(enabled && marked);
            pasteAction.setEnabled(enabled && editable && pasteAvailable);
            selectAllAction.setEnabled(enabled && nonempty);

            int nx = e.getX();

            if (nx > 500) {
                nx = nx - popup.getSize().width;
            }

            popup.show(e.getComponent(), nx, e.getY() - popup.getSize().height);
        }
    }
}

最后,您应该将此侦听器附加到您希望右键单击上下文菜单的任何文本组件.