无法从JavaFX中的MenuItem获取场景 [英] Unable to get Scene from MenuItem in JavaFX
本文介绍了无法从JavaFX中的MenuItem获取场景的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试根据menuItem单击改变javafx阶段的场景。这是我的sample.fxml：
I am trying to change the scene in a javafx stage based on menuItem click. Here is my sample.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import java.net.*?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.*?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.image.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.GridPane?>
<AnchorPane prefHeight="-1.0" prefWidth="560.0" styleClass="background" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/2.2" fx:controller="sample.Controller">
<children>
<MenuBar layoutY="0.0" maxWidth="1.7976931348623157E308" prefWidth="300.0" useSystemMenuBar="false" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="2.0">
<menus>
<Menu id="manageAccountsMenu" mnemonicParsing="false" onAction="#onManageAccountsMenuActionPerformed" text="Accounts" fx:id="manageAccountsMenu">
<items>
<MenuItem mnemonicParsing="false" onAction="#onTweetsMenuActionPerformed" text="Manage" fx:id="manageAccountsSubmenuItem" />
</items>
</Menu>
<Menu mnemonicParsing="false" onAction="#onTweetsMenuActionPerformed" text="Tweets" fx:id="tweetsMenuItem" />
<Menu mnemonicParsing="false" text="Retweets" />
</menus>
</MenuBar>
<VBox id="VBox" alignment="CENTER" layoutY="24.0" spacing="5.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0">
<children>
<ScrollPane id="ScrollPane" fitToHeight="true" fitToWidth="true" prefViewportHeight="400.0" prefViewportWidth="300.0">
<content>
<TableView prefHeight="-1.0" prefWidth="-1.0" tableMenuButtonVisible="true">
<columns>
<TableColumn editable="false" prefWidth="75.0" text="SNO" />
<TableColumn prefWidth="200.0" text="Account" />
<TableColumn prefWidth="200.0" text="Status" />
<TableColumn prefWidth="75.0" text="Actions" />
</columns>
</TableView>
</content>
</ScrollPane>
<Button mnemonicParsing="false" text="Add Account" textAlignment="CENTER">
<graphic>
<ImageView fitHeight="150.0" fitWidth="200.0" mouseTransparent="true" pickOnBounds="true" preserveRatio="true">
<image>
<Image url="@addAccount.png" />
</image>
</ImageView>
</graphic>
</Button>
</children>
</VBox>
</children>
<stylesheets>
<URL value="@darkTheme.css" />
</stylesheets>
</AnchorPane>
这是我的Controller.java：
Here is my Controller.java:
package sample;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.MenuItem;
import javafx.stage.Stage;
import java.net.URL;
import java.util.ResourceBundle;
public class Controller implements Initializable {
@FXML
protected void onManageAccountsMenuActionPerformed(ActionEvent event) {
System.out.println("Manage Accbtnclick");
// Node node=(Node) event.getSource();
// Stage stage=(Stage) node.getScene().getWindow();
//
// Scene scene = new Scene(root);
// stage.setScene(scene);
// stage.show();
}
@FXML
protected void onTweetsMenuActionPerformed(ActionEvent event) {
System.out.println("Manage Accbtnclick");
Node node= (Node)event.getSource();
Stage stage=(Stage) node.getScene().getWindow();
Scene scene = Main.screens.get("tweet");
stage.setScene(scene);
stage.show();
}
@Override
public void initialize(URL url, ResourceBundle resourceBundle) {
//To change body of implemented methods use File | Settings | File Templates.
}
}
这是我的Main.java：
Here is my Main.java:
package sample;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.geometry.Pos;
import javafx.scene.Group;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.ProgressBar;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import java.io.IOException;
import java.util.HashMap;
public class Main extends Application {
public static HashMap<String,Scene> screens=new HashMap<String,Scene>();
@Override
public void start(Stage stage) {
try {
Parent accountScreen= FXMLLoader.load(getClass().getResource("sample.fxml"));
Parent tweetScreen=FXMLLoader.load(getClass().getResource("tweetform.fxml"));
//Parent retweetScreen=FXMLLoader.load(getClass().getResource("retweetform.fxml"));
screens.put("account",new Scene(accountScreen));
screens.put("tweet",new Scene(tweetScreen));
//screens.put("retweet",new Scene(retweetScreen));
stage.setTitle("Manage Accounts");
stage.setScene(screens.get("account"));
stage.show();
} catch (IOException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
}
}
public static void main(String[] args) {
launch(args);
}
}
当我点击帐户菜单下的菜单项管理，我得到以下异常：
When I click on the menuItem Manage under Accounts Menu, I get the following exception:
"C:\Program Files\Java\jdk1.7.0_17\bin\java" -Didea.launcher.port=7541 "-Didea.launcher.bin.path=C:\Program Files (x86)\JetBrains\IntelliJ IDEA 12.1.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.7.0_17\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jce.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfxrt.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\resources.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\rt.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\zipfs.jar;C:\Users\rahulserver\IdeaProjects\DrawingText\out\production\DrawingText;C:\Program Files (x86)\JetBrains\IntelliJ IDEA 12.1.4\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain sample.Main
Manage Accbtnclick
Manage Accbtnclick
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1440)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:69)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:28)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.control.MenuItem.fire(MenuItem.java:456)
at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer.doSelect(ContextMenuContent.java:1188)
at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer$6.handle(ContextMenuContent.java:1139)
at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer$6.handle(ContextMenuContent.java:1137)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:69)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3328)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3168)
at javafx.scene.Scene$MouseHandler.access$1900(Scene.java:3123)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1563)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2265)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:250)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:173)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:292)
at com.sun.glass.ui.View.handleMouseEvent(View.java:528)
at com.sun.glass.ui.View.notifyMouse(View.java:922)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:29)
at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:73)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:55)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:269)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1435)
... 40 more
Caused by: java.lang.ClassCastException: javafx.scene.control.MenuItem cannot be cast to javafx.scene.Node
at sample.Controller.onTweetsMenuActionPerformed(Controller.java:29)
... 50 more
那么如何从菜单项点击包含舞台/场景点击事件处理程序？
So how do I get the containing stage/scene from the menu Item clicked event handler?
编辑
行
Node node= (Node)event.getSource();
在controller.java中是行号29，这是给出问题。
in controller.java is line number 29 which is giving problems.
推荐答案
您的实际错误显示在堆栈跟踪的第二行到最后一行：
Your real error is shown in the second to last line of the stack trace:
Caused by: java.lang.ClassCastException: javafx.scene.control.MenuItem cannot be cast to javafx.scene.Node
at sample.Controller.onTweetsMenuActionPerformed(Controller.java:29)
此错误是指控制器中的以下行： p>
This error is referring to the following line from your controller:
Node node= (Node)event.getSource();
查看JavaFX API文档，MenuItem和Menu都不是Node的子类。 http://docs.oracle.com/javafx/2/api/javafx/场景/控制/ MenuItem.html
http：/ /docs.oracle.com/javafx/2/api/javafx/scene/control/Menu.html
Looking at the JavaFX API Docs, neither MenuItem nor Menu are subclasses of Node. http://docs.oracle.com/javafx/2/api/javafx/scene/control/MenuItem.html http://docs.oracle.com/javafx/2/api/javafx/scene/control/Menu.html
我建议把源作为一个对象，然后在继续之前检查其类型。另外，我遇到了使用getSource（）方法的问题; getTarget（）方法对我来说效果更好。无论哪种方式，您仍然需要一种方式才能进入舞台。
I would suggest grabbing the source as an Object, then checking its type before continuing. Also, I ran into problems using the getSource() method; the getTarget() method worked better for me. Either way, you still need a way to get the to the Stage.
为此，您可能需要使用 fx：id 标签，而不是 id 标签。这将允许您将FXML元素直接注入到控制器中。例如，您可以通过将MenuBar元素注入到控制器中，从MenuBar（它是Node的子类）中获取Stage。
To do this, you might want to use the fx:id tag in your FXML instead of the id tag. This will allow you to inject the FXML elements directly into your controller. For example, you could grab the Stage from the MenuBar (which is a subclass of Node) by injecting the MenuBar element into your controller.
在FXML中：
<MenuBar fx:id="myMenuBar" layoutY="0.0" maxWidth="1.7976931348623157E308" prefWidth="300.0" useSystemMenuBar="false" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="2.0">
在控制器中：
public class Controller implements Initializable {
@FXML MenuBar myMenuBar;
...
@FXML
protected void onTweetsMenuActionPerformed(ActionEvent event) {
System.out.println("Manage Accbtnclick");
Stage stage = (Stage) myMenuBar.getScene().getWindow();
Scene scene = Main.screens.get("tweet");
stage.setScene(scene);
stage.show();
}
...
}
您可能需要在这里做一些调整，但希望它有帮助。
You may need to do a bit of tweaking here, but hopefully it helps.
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