JavaFxでComboBoxオブジェクトにActionを追加した後、ComboBoxを編集できるようにするには

Question

JavaFxでは、ComboBoxオブジェクトにActionを追加した後、どのようにComboBoxを編集できるようにしますか？私はそれが動作するが、私はエラーが発生するが、私は何かが欠落しているエラーを取得します。私はまだJavafxの初心者です。ここにコードがあります。

私が正確にしようとしているのは、ユーザーにいくつかの固定項目を与えることですが、まずユーザーがコンボボックスから他を選択すると、コンボボックスが編集可能になります。ボタンから編集可能なコンボボックスを設定すると完全にうまく動作します。私はコンボボックスに影響を与える方法を作りました。 JAVAを理解していればコードを見てください。

import javafx.application.Application; 
import javafx.geometry.Insets; 
import javafx.scene.Scene; 
import javafx.scene.control.Button; 
import javafx.scene.control.ComboBox; 
import javafx.scene.control.Label; 
import javafx.scene.layout.VBox; 
import javafx.stage.Stage; 

public class main extends Application{ 

    ComboBox<String> cb = new ComboBox<>(); 

    public static void main(String[] args) { 

     launch(args); 
    } 

    @Override 
    public void start(Stage stage) throws Exception { 

     Button b = new Button("GOOWE"); 

     Label choice = new Label("What type of Vehicle do you drive"); 
     cb.getItems().addAll("Car","Jeep","Bus","Other"); 

     cb.setPromptText("Select your Vehicle"); 

     cb.setOnAction(e ->{ 

      if (cb.getValue().equals("Other")){ 
       //Both the editable and cb.setEditable still give error in the terminal 
       editable(cb); 
       //cb.setEditable(true); 
      } 

     }); 
     VBox layout = new VBox(10); 

     layout.setPadding(new Insets(10,10,10,10)); 
     layout.getChildren().addAll(choice,cb,b); 

     b.setOnAction(e -> { 

     cb.setEditable(true); 

     }); 

     Scene sc = new Scene(layout,200,400); 

     stage.setScene(sc); 

     stage.show(); 

    } 

    private void editable(ComboBox<String> cb2) { 

      cb2.setEditable(true); 

    } 

} 

これはエラー

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException 
    at pk8.main.lambda$0(main.java:44) 
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86) 
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238) 
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191) 
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74) 
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49) 
    at javafx.event.Event.fireEvent(Event.java:198) 
    at javafx.scene.Node.fireEvent(Node.java:8413) 
    at com.sun.javafx.scene.control.skin.ComboBoxListViewSkin.handleControlPropertyChanged(ComboBoxListViewSkin.java:179) 
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase.lambda$registerChangeListener$61(BehaviorSkinBase.java:197) 
    at com.sun.javafx.scene.control.MultiplePropertyChangeListenerHandler$1.changed(MultiplePropertyChangeListenerHandler.java:55) 
    at javafx.beans.value.WeakChangeListener.changed(WeakChangeListener.java:89) 
    at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361) 
    at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81) 
    at javafx.beans.property.ObjectPropertyBase.fireValueChangedEvent(ObjectPropertyBase.java:105) 
    at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112) 
    at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146) 
    at javafx.scene.control.ComboBoxBase.setValue(ComboBoxBase.java:150) 
    at javafx.scene.control.ComboBox.updateValue(ComboBox.java:463) 
    at javafx.scene.control.ComboBox.access$200(ComboBox.java:192) 
    at javafx.scene.control.ComboBox$3.changed(ComboBox.java:446) 
    at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361) 
    at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81) 
    at javafx.beans.property.ReadOnlyObjectPropertyBase.fireValueChangedEvent(ReadOnlyObjectPropertyBase.java:74) 
    at javafx.beans.property.ReadOnlyObjectWrapper.fireValueChangedEvent(ReadOnlyObjectWrapper.java:102) 
    at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112) 
    at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146) 
    at javafx.scene.control.SelectionModel.setSelectedItem(SelectionModel.java:102) 
    at javafx.scene.control.ComboBox$ComboBoxSelectionModel.lambda$new$154(ComboBox.java:494) 
    at com.sun.javafx.binding.ExpressionHelper$SingleInvalidation.fireValueChangedEvent(ExpressionHelper.java:137) 
    at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81) 
    at javafx.beans.property.ReadOnlyIntegerPropertyBase.fireValueChangedEvent(ReadOnlyIntegerPropertyBase.java:72) 
    at javafx.beans.property.ReadOnlyIntegerWrapper.fireValueChangedEvent(ReadOnlyIntegerWrapper.java:102) 
    at javafx.beans.property.IntegerPropertyBase.markInvalid(IntegerPropertyBase.java:113) 
    at javafx.beans.property.IntegerPropertyBase.set(IntegerPropertyBase.java:147) 
    at javafx.scene.control.SelectionModel.setSelectedIndex(SelectionModel.java:68) 
    at javafx.scene.control.SingleSelectionModel.updateSelectedIndex(SingleSelectionModel.java:215) 
    at javafx.scene.control.SingleSelectionModel.clearSelection(SingleSelectionModel.java:68) 
    at javafx.scene.control.ComboBox.lambda$new$153(ComboBox.java:269) 
    at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:349) 
    at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81) 
    at javafx.beans.property.BooleanPropertyBase.fireValueChangedEvent(BooleanPropertyBase.java:103) 
    at javafx.beans.property.BooleanPropertyBase.markInvalid(BooleanPropertyBase.java:110) 
    at javafx.beans.property.BooleanPropertyBase.set(BooleanPropertyBase.java:144) 
    at javafx.scene.control.ComboBoxBase.setEditable(ComboBoxBase.java:164) 
    at pk8.main.editable(main.java:78) 
    at pk8.main.lambda$0(main.java:46) 
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86) 
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238) 
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191) 
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74) 
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49) 
    at javafx.event.Event.fireEvent(Event.java:198) 
    at javafx.scene.Node.fireEvent(Node.java:8413) 
    at com.sun.javafx.scene.control.skin.ComboBoxListViewSkin.handleControlPropertyChanged(ComboBoxListViewSkin.java:179) 
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase.lambda$registerChangeListener$61(BehaviorSkinBase.java:197) 
    at com.sun.javafx.scene.control.MultiplePropertyChangeListenerHandler$1.changed(MultiplePropertyChangeListenerHandler.java:55) 
    at javafx.beans.value.WeakChangeListener.changed(WeakChangeListener.java:89) 
    at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361) 
    at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81) 
    at javafx.beans.property.ObjectPropertyBase.fireValueChangedEvent(ObjectPropertyBase.java:105) 
    at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112) 
    at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146) 
    at javafx.scene.control.ComboBoxBase.setValue(ComboBoxBase.java:150) 
    at javafx.scene.control.ComboBox.updateValue(ComboBox.java:463) 
    at javafx.scene.control.ComboBox.access$200(ComboBox.java:192) 
    at javafx.scene.control.ComboBox$3.changed(ComboBox.java:446) 
    at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361) 
    at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81) 
    at javafx.beans.property.ReadOnlyObjectPropertyBase.fireValueChangedEvent(ReadOnlyObjectPropertyBase.java:74) 
    at javafx.beans.property.ReadOnlyObjectWrapper.fireValueChangedEvent(ReadOnlyObjectWrapper.java:102) 
    at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112) 
    at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146) 
    at javafx.scene.control.SelectionModel.setSelectedItem(SelectionModel.java:102) 
    at javafx.scene.control.ComboBox$ComboBoxSelectionModel.lambda$new$154(ComboBox.java:494) 
    at com.sun.javafx.binding.ExpressionHelper$SingleInvalidation.fireValueChangedEvent(ExpressionHelper.java:137) 
    at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81) 
    at javafx.beans.property.ReadOnlyIntegerPropertyBase.fireValueChangedEvent(ReadOnlyIntegerPropertyBase.java:72) 
    at javafx.beans.property.ReadOnlyIntegerWrapper.fireValueChangedEvent(ReadOnlyIntegerWrapper.java:102) 
    at javafx.beans.property.IntegerPropertyBase.markInvalid(IntegerPropertyBase.java:113) 
    at javafx.beans.property.IntegerPropertyBase.set(IntegerPropertyBase.java:147) 
    at javafx.scene.control.SelectionModel.setSelectedIndex(SelectionModel.java:68) 
    at javafx.scene.control.SingleSelectionModel.updateSelectedIndex(SingleSelectionModel.java:215) 
    at javafx.scene.control.SingleSelectionModel.select(SingleSelectionModel.java:149) 
    at com.sun.javafx.scene.control.skin.ComboBoxListViewSkin.lambda$createListView$323(ComboBoxListViewSkin.java:484) 
    at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:349) 
    at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81) 
    at javafx.beans.property.ReadOnlyIntegerPropertyBase.fireValueChangedEvent(ReadOnlyIntegerPropertyBase.java:72) 
    at javafx.beans.property.ReadOnlyIntegerWrapper.fireValueChangedEvent(ReadOnlyIntegerWrapper.java:102) 
    at javafx.beans.property.IntegerPropertyBase.markInvalid(IntegerPropertyBase.java:113) 
    at javafx.beans.property.IntegerPropertyBase.set(IntegerPropertyBase.java:147) 
    at javafx.scene.control.SelectionModel.setSelectedIndex(SelectionModel.java:68) 
    at javafx.scene.control.MultipleSelectionModelBase.select(MultipleSelectionModelBase.java:404) 
    at javafx.scene.control.MultipleSelectionModelBase.clearAndSelect(MultipleSelectionModelBase.java:356) 
    at javafx.scene.control.ListView$ListViewBitSetSelectionModel.clearAndSelect(ListView.java:1403) 
    at com.sun.javafx.scene.control.behavior.CellBehaviorBase.simpleSelect(CellBehaviorBase.java:256) 
    at com.sun.javafx.scene.control.behavior.CellBehaviorBase.doSelect(CellBehaviorBase.java:220) 
    at com.sun.javafx.scene.control.behavior.CellBehaviorBase.mousePressed(CellBehaviorBase.java:150) 
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:95) 
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89) 
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218) 
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80) 
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238) 
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191) 
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74) 
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54) 
    at javafx.event.Event.fireEvent(Event.java:198) 
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3757) 
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485) 
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762) 
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:381) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:417) 
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416) 
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555) 
    at com.sun.glass.ui.View.notifyMouse(View.java:937) 
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) 
    at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191) 
    at java.lang.Thread.run(Thread.java:748) 
Exception in thread "JavaFX Application Thread" java.lang.IndexOutOfBoundsException 
    at com.sun.javafx.scene.control.ReadOnlyUnbackedObservableList.subList(ReadOnlyUnbackedObservableList.java:136) 
    at javafx.collections.ListChangeListener$Change.getAddedSubList(ListChangeListener.java:242) 
    at com.sun.javafx.scene.control.behavior.ListViewBehavior.lambda$new$177(ListViewBehavior.java:269) 
    at javafx.collections.WeakListChangeListener.onChanged(WeakListChangeListener.java:88) 
    at com.sun.javafx.collections.ListListenerHelper$Generic.fireValueChangedEvent(ListListenerHelper.java:329) 
    at com.sun.javafx.collections.ListListenerHelper.fireValueChangedEvent(ListListenerHelper.java:73) 
    at com.sun.javafx.scene.control.ReadOnlyUnbackedObservableList.callObservers(ReadOnlyUnbackedObservableList.java:75) 
    at javafx.scene.control.MultipleSelectionModelBase.clearAndSelect(MultipleSelectionModelBase.java:378) 
    at javafx.scene.control.ListView$ListViewBitSetSelectionModel.clearAndSelect(ListView.java:1403) 
    at com.sun.javafx.scene.control.behavior.CellBehaviorBase.simpleSelect(CellBehaviorBase.java:256) 
    at com.sun.javafx.scene.control.behavior.CellBehaviorBase.doSelect(CellBehaviorBase.java:220) 
    at com.sun.javafx.scene.control.behavior.CellBehaviorBase.mousePressed(CellBehaviorBase.java:150) 
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:95) 
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89) 
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218) 
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80) 
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238) 
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191) 
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74) 
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54) 
    at javafx.event.Event.fireEvent(Event.java:198) 
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3757) 
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485) 
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762) 
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:381) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:417) 
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416) 
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555) 
    at com.sun.glass.ui.View.notifyMouse(View.java:937) 
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) 
    at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191) 
    at java.lang.Thread.run(Thread.java:748) 

Answer 1

は基本的に、それはFX8にバグですされています。ほぼすべてのselectionModelsはひどく壊れています。あなたのコード内でスローNPEの正確な理由は二つある：

1. アクションハンドラが最初にコンボの値を呼び出し、2回呼び出され第二に、@Mするヌル（栄光である「その他」でありますそれを見つけるためのleRutte） - ！それは
2. FXのバグだあなたは値がif (cb.getValue().equals("Other"))とnullでないことを前提としてNPEは、周りに2回目に発生 - このようなチェックは、より良いラウンド、他の方法で処理され、それがif ("Other".equals(cb.getValue()))
です

しかし、逆のチェックをしても、編集可能性を設定すると、IndexOutOfBoundsでfx8がスローアップされます。 MultipleSelectionModelBaseの実装が壊れています（fx9で改善されました）。可能であればアップグレードしてください。

fx8でも可能ですが、ポップアップが開いている間に編集可能なプロパティが変更された場合にのみエラーが発生するようです。 ：だから私は若干の不具合が残っているコンボのvaluePropertyに耳を傾け、

を示していないこと

編集可能な値をチェックし、設定onHiddenになeventHandlerをインストールしている場合にのみ編集可能な更新

• にロジックを変更しました入力フィールドにフォーカスを転送
  • は、内部に
  • マーカーVを微調整する必要がALUE（AKS「その他」）は、おそらく値であるヌルtemporariyに関連し、さらに掘るするのが面倒、テキストフィールドに示されていない

  変形例：の

  public class ComboBoxActionEditable extends Application{ 
  
      ComboBox<String> cb = new ComboBox<>(); 
  
      /** 
      * Sets the combo's editable if given value equals the marker. 
      * @param nv the value to test 
      */ 
      protected void updateEditable(String nv) { 
       if ("Other".equals(nv)) { 
        cb.setEditable(true); 
        FakeFocusTextField textField = (FakeFocusTextField) cb.getEditor(); 
        textField.requestFocus(); 
        textField.setFakeFocus(true); 
       } 
      } 
  
      @Override 
      public void start(Stage stage) throws Exception { 
  
       Button b = new Button("GOOWE"); 
  
       Label choice = new Label("What type of Vehicle do you drive"); 
       cb.getItems().addAll("Car","Jeep","Bus","Other"); 
  
       cb.setPromptText("Select your Vehicle"); 
  
       cb.valueProperty().addListener((src, ov, nv) -> { 
        // fx8 bug: internals blow up when changing editable while showing 
        if (cb.isShowing() || cb.isEditable()) return; 
        updateEditable(nv); 
       }); 
  
       // hack around fx8 bug: 
       cb.setOnHidden(e -> { 
        if (cb.isEditable()) return; 
        updateEditable(cb.getValue()); 
  
       }); 
  
       // to see that editable is switched and textField focused 
       // when changing the value programmatically 
       b.setOnAction(e -> { 
        cb.setValue("Other"); 
       }); 
  
       VBox layout = new VBox(10); 
       layout.setPadding(new Insets(10,10,10,10)); 
       layout.getChildren().addAll(choice,cb,b); 
       Scene sc = new Scene(layout,200,400); 
       stage.setScene(sc); 
       stage.setTitle(FXUtils.version()); 
       stage.show(); 
  
      } 
  
      public static void main(String[] args) { 
       launch(args); 
      } 
  }