JavaFX 2.0 像 MenuItem 一样激活菜单 [英] JavaFX 2.0 Activating a Menu like a MenuItem

问题描述

我正在制作一个 MenuBar，但我不需要按 Menu 的功能，例如:文件"然后执行操作.比如打开另一个fxml，或者写一些输出的例子.

I'm making a MenuBar, and I wan't the functionality to press a Menu like: "File" and then execute a action. Such like opening an other fxml, or an example where some output is written.

我想要Menu 中的MenuItem(谎言关于")的功能，比如文件".

I want the functionality of a MenuItem (lie "About") in a Menu like "File".

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);
   }
}

推荐答案

AFAIK, A Menu，如果没有任何添加的子菜单或 Menuitems，不会触发事件无论是点击、显示还是隐藏.但是，解决方法是将其图形设置为该图形节点将处理鼠标单击的位置，例如，

AFAIK, A Menu, if has not any added submenu or Menuitems, does not fire events neither on click, on shown nor on hide. However the workaround is to set its graphic where this graphic node will handle mouse clicks for example,

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没有覆盖菜单的所有空间，导致点击菜单边缘不会触发鼠标事件.通过取消注释上面的 menuLabel.setStyle 行来查看这一点.但这可以通过我认为使用 CSS 样式来解决.
代码部分取自使用舞台创建对话框.您还可以使用 FXMLLoader 将 FXML 文件加载到 myDialog 阶段.网上有很多关于它的例子.

A drawback of this approach is that the label do not cover all spaces of the menu resulting clicking on edges of menu is not triggering the mouse event. See this by uncommenting menuLabel.setStyle line above. But this can be resolved by playing with CSS styles I think.
Code is partially taken from Create Dialog using Stage. You can also load an FXML file into the myDialog stage using the FXMLLoader. There are lots of examples about it on the net.

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