javafx fxml menuitem onaction错误

Question

所以我在第一次尝试编写一些东西时创建了一个小程序，我遇到了我的菜单栏的问题。 我用scenebuilder创建了所有东西，当我添加一个onAction事件时，我一直收到错误，我也找不到解决方案。

这是我的fxml代码

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Menu?>
<?import javafx.scene.control.MenuBar?>
<?import javafx.scene.control.MenuItem?>
<?import javafx.scene.layout.AnchorPane?>

<fx:root id="AnchorPane" prefHeight="400.0" prefWidth="600.0" type="AnchorPane" xmlns="http://javafx.com/javafx/8.0.102" xmlns:fx="http://javafx.com/fxml/1">
   <children>
      <MenuBar fx:id="HoofdMenu" layoutY="2.0" prefHeight="25.0" prefWidth="600.0">
        <menus>
          <Menu mnemonicParsing="false" text="Maaltafels">
            <items>
              <MenuItem fx:id="maal10" mnemonicParsing="false" onAction="#maal10Selected" text="Tot maal 10" />
              <MenuItem fx:id="maal100" mnemonicParsing="false" onAction="#maal100Clicked" text="Tot maal 100" />
              <MenuItem mnemonicParsing="false" text="Tot maal 1000" />
            </items>
          </Menu>
        </menus>
      </MenuBar>
   </children>
</fx:root>

这是我打开屏幕并执行操作的代码

package gui;

import domein.DomeinController;
import java.awt.MenuBar;
import java.awt.MenuItem;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.layout.AnchorPane;
import javafx.stage.Stage;

public class StartschermController extends AnchorPane{
    private DomeinController dc;

    @FXML
    private MenuBar menuBar;
    @FXML
    private MenuItem maal10;   
    @FXML
    private MenuItem maal100;
    public StartschermController(DomeinController dc) throws MalformedURLException{
        this.dc = dc;
        String stringFxml = "file:///c:/Users/jelle/Documents/NetBeansProjects/ProjectenI/WiskundeOefFX/src/gui/StartScherm.fxml";
        URL fxml = new URL(stringFxml);

        FXMLLoader loader = new FXMLLoader();
        loader.setLocation(fxml);
        loader.setRoot(this);
        loader.setController(this);
        try{
            loader.load();
        }catch(IOException ex){
            throw  new RuntimeException(ex);
        }
    }

    @FXML
    public void maal10Selected(javafx.event.ActionEvent event){
        String stringoefeningen = "file:///c:/Users/jelle/Documents/NetBeansProjects/ProjectenI/WiskundeOefFX/src/gui/oefeningen.fxml";
        try {
            URL oefeningen = new URL(stringoefeningen);
            FXMLLoader oefeningenLoader = new FXMLLoader();
            OefeningenController controller = new OefeningenController(dc);
            oefeningenLoader.setLocation(oefeningen);
            oefeningenLoader.setController(controller);
            Parent root = (Parent) oefeningenLoader.load();
            Stage stage = new Stage();
            stage.setTitle("Maaltafels");
            stage.setScene(new Scene(root));  
            stage.show();
        } catch (MalformedURLException ex) {
            Logger.getLogger(StartschermController.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(StartschermController.class.getName()).log(Level.SEVERE, null, ex);
        }

       dc.setMoeilijkheidsGraad(1);
    }

这是我得到的错误列表

java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
    at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$156(LauncherImpl.java:182)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.RuntimeException: javafx.fxml.LoadException: 
/c:/Users/jelle/Documents/NetBeansProjects/ProjectenI/WiskundeOefFX/src/gui/StartScherm.fxml:14

    at gui.StartschermController.<init>(StartschermController.java:42)
    at StartUp.StartUp.start(StartUp.java:24)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$163(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$176(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl.lambda$null$174(PlatformImpl.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(PlatformImpl.java:294)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$149(WinApplication.java:191)
    ... 1 more
Caused by: javafx.fxml.LoadException: 
/c:/Users/jelle/Documents/NetBeansProjects/ProjectenI/WiskundeOefFX/src/gui/StartScherm.fxml:14

    at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2579)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2409)
    at gui.StartschermController.<init>(StartschermController.java:40)
    ... 10 more
Caused by: java.lang.IllegalArgumentException: Can not set java.awt.MenuItem field gui.StartschermController.maal10 to javafx.scene.control.MenuItem
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)
    at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:81)
    at java.lang.reflect.Field.set(Field.java:764)
    at javafx.fxml.FXMLLoader.injectFields(FXMLLoader.java:1163)
    at javafx.fxml.FXMLLoader.access$1600(FXMLLoader.java:103)
    at javafx.fxml.FXMLLoader$ValueElement.processValue(FXMLLoader.java:857)
    at javafx.fxml.FXMLLoader$ValueElement.processStartElement(FXMLLoader.java:751)
    at javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2707)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2527)
    ... 13 more
Exception running application StartUp.StartUp
Java Result: 1

你们可以帮助我吗？