JavaFX 2.0激活菜单,如MenuItem

我正在制作一个MenuBar,而且我无法按下菜单的功能：“File”,然后执行一个动作.就像打开一个其他的fxml,或者是一些写出一些输出的例子.

我想要一个MenuItem(在“About”)的功能,如“File”菜单.

package model;

import static java.lang.System.out;

import javafx.application.Application;
import javafx.beans.property.ReadOnlyDoubleProperty;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Pos;
import javafx.geometry.Side;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyCodeCombination;
import javafx.scene.input.KeyCombination;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

/**
 * Example of creating menus in JavaFX.
 * 
 * @author Dustin
 */
public class JavaFxMenus extends Application
{
   /**
    * Build menu bar with included menus for this demonstration.
    * 
    * @param menuWidthProperty Width to be bound to menu bar width.
    * @return Menu Bar with menus included.
    */
   private MenuBar buildMenuBarWithMenus(final ReadOnlyDoubleProperty menuWidthProperty)
   {
      final MenuBar menuBar = new MenuBar();

      // Prepare left-most 'File' drop-down menu
      final Menu fileMenu = new Menu("File");

      menuBar.getMenus().add(fileMenu);
      //menuBar.getOnMouseClicked().handle(this);


      // Prepare 'Examples' drop-down menu
      final Menu examplesMenu = new Menu("JavaFX 2.0 Examples");
      examplesMenu.getItems().add(new MenuItem("Text Example"));
      examplesMenu.getItems().add(new MenuItem("Objects Example"));
      examplesMenu.getItems().add(new MenuItem("Animation Example"));
      menuBar.getMenus().add(examplesMenu);

      // Prepare 'Help' drop-down menu
      final Menu helpMenu = new Menu("Help");
      helpMenu.setOnAction(null);

      final MenuItem searchMenuItem = new MenuItem("Search");
      searchMenuItem.setDisable(true);
      helpMenu.getItems().add(searchMenuItem);
      final MenuItem onlineManualMenuItem = new MenuItem("Online Manual");
      onlineManualMenuItem.setVisible(false);
      helpMenu.getItems().add(onlineManualMenuItem);
      helpMenu.getItems().add(new SeparatorMenuItem());
      final MenuItem aboutMenuItem =
         MenuItemBuilder.create()
                        .text("About")
                        .onAction(
                            new EventHandler<ActionEvent>()
                            {
                               @Override public void handle(ActionEvent e)
                               {
                                  out.println("You clicked on About!");
                               }
                            })
                        .accelerator(
                            new KeyCodeCombination(
                               KeyCode.A,KeyCombination.CONTROL_DOWN))
                        .build();             
      helpMenu.getItems().add(aboutMenuItem);
      menuBar.getMenus().add(helpMenu);

      // bind width of menu bar to width of associated stage
      menuBar.prefWidthProperty().bind(menuWidthProperty);

      return menuBar;
   }

   /**
    * Start of JavaFX application demonstrating menu support.
    * 
    * @param stage Primary stage.
    */
   @Override
   public void start(final Stage stage)
   {
      stage.setTitle("Creating Menus with JavaFX 2.0");
      final Group rootGroup = new Group();
      final Scene scene = new Scene(rootGroup,800,400,Color.WHEAT);



      final MenuBar menuBar = buildMenuBarWithMenus(stage.widthProperty());
      rootGroup.getChildren().add(menuBar);
      stage.setScene(scene);
      stage.show();
   }

   /**
    * Main executable function for running examples.
    * 
    * @param arguments Command-line arguments: none expected.
    */
   public static void main(final String[] arguments)
   {
      Application.launch(arguments);
   }
}

解决方法

AFAIK,A菜单,如果没有任何添加子菜单或Menuitems,则不会在点击,显示或隐藏上触发事件.但是,解决方法是设置其图形,其中该图形节点将处理鼠标点击,例如,

Label menuLabel = new Label("File");
menuLabel.setOnMouseClicked(new EventHandler<MouseEvent>() {
    @Override
    public void handle(MouseEvent event) {

        Stage myDialog = new Stage();
        myDialog.initModality(Modality.WINDOW_MODAL);

        Scene myDialogScene = new Scene(VBoxBuilder.create()
            .children(new Text("Hello! it's My Dialog."))
            .alignment(Pos.CENTER)
            .padding(new Insets(10))
            .build());

        myDialog.setScene(myDialogScene);
        myDialog.show();
    }
});
Menu fileMenuButton = new Menu();
fileMenuButton.setGraphic(menuLabel);
menuBar.getMenus().add(fileMenuButton);

这种方法的一个缺点是标签不覆盖菜单的所有空格,从而点击菜单边缘不会触发鼠标事件.通过取消注释menuLabel.setStyle行,看到这一点.但是,这可以通过使用我认为的CSS样式来解决.
代码部分取自Create Dialog using Stage.您还可以使用FXMLLoader将FXML文件加载到myDialog阶段.网上有很多例子.