JavaFX:Can'；t调用应用程序'；匿名类中的标签字段？

我正在组装一个JavaFX应用程序，并试图通过在程序后端的侦听器表中添加一个匿名类来更改标签的文本。虽然侦听器将返回它应该获取的数据，但当匿名类更改标签时，JavaFX将崩溃

前端：

public class App extends Application {

...

final BackendElement backendElement = new BackendElement();

...

    @Override
    public void start(Stage mainStage) {

         ...

       GridPane stageContents = generateGridPane(mainStage);

         ...

       mainStage.setScene(new Scene(stageContents));
       mainStage.show();
    }


    private GridPane getGridPane(final Stage mainStage) {

          ...

        final Label labelToBeUpdated = new Label("");

          ...

        backendElement.addModelChangedListener(new ModelChangedListener() {
             @Override
             public void modelChanged(ModelChangedEvent ev) {
                 labelToBeUpdated.setText(ev.getSource()); //<- Causes verbose JFX Exception
             }
        });
    }

将打印出所需的数据

我认为私有类的标签不能从匿名类调用。事实证明，App类中的final字段也不能。有没有一种方法可以在不丢失观察者模式的情况下修复此问题

以下是完整的堆栈跟踪：

Exception in thread "Timer-0" java.lang.IllegalStateException: Not on FX application thread; currentThread = Timer-0
at com.sun.javafx.tk.Toolkit.checkFxUserThread(Toolkit.java:237)
at com.sun.javafx.tk.quantum.QuantumToolkit.checkFxUserThread(QuantumToolkit.java:397)
at javafx.scene.Parent$1.onProposedChange(Parent.java:245)
at com.sun.javafx.collections.VetoableObservableList.setAll(VetoableObservableList.java:90)
at com.sun.javafx.collections.ObservableListWrapper.setAll(ObservableListWrapper.java:314)
at com.sun.javafx.scene.control.skin.LabeledSkinBase.updateChildren(LabeledSkinBase.java:602)
at com.sun.javafx.scene.control.skin.LabeledSkinBase.handleControlPropertyChanged(LabeledSkinBase.java:209)
at com.sun.javafx.scene.control.skin.SkinBase$3.changed(SkinBase.java:282)
at javafx.beans.value.WeakChangeListener.changed(WeakChangeListener.java:107)
at com.sun.javafx.binding.ExpressionHelper$SingleChange.fireValueChangedEvent(ExpressionHelper.java:196)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:100)
at javafx.beans.property.StringPropertyBase.fireValueChangedEvent(StringPropertyBase.java:121)
at javafx.beans.property.StringPropertyBase.markInvalid(StringPropertyBase.java:128)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:161)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:67)
at javafx.beans.property.StringProperty.setValue(StringProperty.java:84)
at javafx.scene.control.Labeled.setText(Labeled.java:135)
at ui.App$12.modelChanged(App.java:349)
at ui.BackendElement$CustomTimerTask.informAllListeners(BackendElement.java:108)
at ui.BackendElement$CustomTimerTask.access$0(BackendElement.java:105)
at ui.BackendElement$CustomTimerTask$1.run(BackendElement.java:87)
at java.util.TimerThread.mainLoop(Unknown Source)
at java.util.TimerThread.run(Unknown Source)

解决方案： 使用Platform.runLater（）包装您希望侦听器执行的任何操作

解决方案： 使用Platform.runLater（）包装您希望侦听器执行的任何操作

Exception in thread "Timer-0" java.lang.IllegalStateException: Not on FX application thread; currentThread = Timer-0
at com.sun.javafx.tk.Toolkit.checkFxUserThread(Toolkit.java:237)
at com.sun.javafx.tk.quantum.QuantumToolkit.checkFxUserThread(QuantumToolkit.java:397)
at javafx.scene.Parent$1.onProposedChange(Parent.java:245)
at com.sun.javafx.collections.VetoableObservableList.setAll(VetoableObservableList.java:90)
at com.sun.javafx.collections.ObservableListWrapper.setAll(ObservableListWrapper.java:314)
at com.sun.javafx.scene.control.skin.LabeledSkinBase.updateChildren(LabeledSkinBase.java:602)
at com.sun.javafx.scene.control.skin.LabeledSkinBase.handleControlPropertyChanged(LabeledSkinBase.java:209)
at com.sun.javafx.scene.control.skin.SkinBase$3.changed(SkinBase.java:282)
at javafx.beans.value.WeakChangeListener.changed(WeakChangeListener.java:107)
at com.sun.javafx.binding.ExpressionHelper$SingleChange.fireValueChangedEvent(ExpressionHelper.java:196)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:100)
at javafx.beans.property.StringPropertyBase.fireValueChangedEvent(StringPropertyBase.java:121)
at javafx.beans.property.StringPropertyBase.markInvalid(StringPropertyBase.java:128)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:161)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:67)
at javafx.beans.property.StringProperty.setValue(StringProperty.java:84)
at javafx.scene.control.Labeled.setText(Labeled.java:135)
at ui.App$12.modelChanged(App.java:349)
at ui.BackendElement$CustomTimerTask.informAllListeners(BackendElement.java:108)
at ui.BackendElement$CustomTimerTask.access$0(BackendElement.java:105)
at ui.BackendElement$CustomTimerTask$1.run(BackendElement.java:87)
at java.util.TimerThread.mainLoop(Unknown Source)
at java.util.TimerThread.run(Unknown Source)

        @Override
        public void modelChanged(ModelChangedEvent ev) {

            final ModelChangedEvent event = ev;

            Platform.runLater(new Runnable(){
                @Override
                public void run() {
                    labelToBeChanged.setText((String)event.getSource());
                }
            });
        }