我有一个JMenuItem并且我想接收用户输入。用户必须能够通过鼠标或键盘启动项目的功能。
该项目的功能包含一个JDialog要打开的。此对话框侦听释放的 ENTER 键并在释放 ENTER 时启动它自己的功能。
当用户点击JMenuItemENTER（按下键）的使用时，他将打开对话框。当他放开 ENTER 时，他会 -这就是问题所在- 导致对话框的功能启动。（当用户放开ENTER键时，他将向现在打开的JDialog. JMenuItem2nd：在 JDialog 中使用 ENTER 启动新功能（完整笔划或 ENTER 释放）。
到目前为止，我已经尝试了几件事，但我无法JMenuItem接收关键发布的事件。这似乎是我目前无法解决的一些焦点问题。
如何解决这个问题？
如果解释有点混乱，可以总结如下：
我想要
JMenuItem接收 ENTER-key-released-events 并对其做出反应，我不希望它对 ENTER-key-pressed-events 做出反应。
一个小代码示例可能会显示我的问题：
编辑
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JRootPane;
import javax.swing.KeyStroke;
import javax.swing.MenuElement;
import javax.swing.MenuSelectionManager;
public class MenuItemProblem {
public static void openDialog(JFrame frame){
Action enterReleasedAction = new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
// This action shall be triggered by releasing
// the enter key in the JDialog.
// (There are two times events of the released enter key shall be
// evaluated during the application runs, of which this is the second one.)
// But: It is triggered by the first release of enter in the application,
// which is the one to choose the menu item.
System.out.println("Dialog: Enter was released!");
}
};
JDialog dialog = new JDialog(frame, "My dialog", true);
JRootPane rootPane = dialog.getRootPane();
ActionMap actionMap = rootPane.getActionMap();
String enterReleased = "my_enter_released_function";
actionMap.put(enterReleased, enterReleasedAction);
InputMap inputMap = rootPane.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
// Keystroke for releasing the enter key
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, true), enterReleased);
dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
dialog.setMinimumSize(new Dimension(260, 300));
dialog.setResizable(true);
dialog.pack();
dialog.setLocationRelativeTo(frame);
dialog.setVisible(true);
}
public static void main(String[] args) {
JFrame frame = new JFrame("My App");
JMenuItem item = new JMenuItem("My item");
item.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// By releasing enter (and mouse clicks, space and so on)
// this action shall be triggered.
// It shall not be triggered by enter key pressed,
// for this would cause the action of the called dialog
// do be triggered.
// But: It is triggered by enter pressed!
// (There are two times events of the released enter key shall be
// evaluated during the application runs, of which this is the first one.)
System.out.println("Choosing the menu item");
openDialog(frame);
}
});
JMenu menu = new JMenu("My menu");
menu.add(item);
JMenuBar bar = new JMenuBar();
bar.add(menu);
// Register alt key to be caught
Action altAction = new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
MenuElement[] elements = MenuSelectionManager.defaultManager().getSelectedPath();
if(elements.length > 0){
MenuSelectionManager.defaultManager().clearSelectedPath();
} else{
menu.doClick();
}
}
};
JRootPane rootPane = frame.getRootPane();
ActionMap actionMap = rootPane.getActionMap();
String altActionKey = "alt_key_for_menu";
actionMap.put(altActionKey, altAction);
InputMap inputMap = rootPane.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
KeyStroke ks = KeyStroke.getKeyStroke(KeyEvent.VK_ALT, 0, true);
inputMap.put(ks, altActionKey);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setJMenuBar(bar);
frame.setSize(350, 250);
frame.setVisible(true);
}
}
是的，如果你们能指出我正确的方向，我会很高兴。在此先感谢并感谢您的所有努力！