在JavaFx中,如何在向ComboBox对象添加Action之后使我的ComboBox可编辑

时间:2017-10-18 08:45:33

标签: java javafx combobox

在JavaFx中,如何在将Action添加到ComboBox对象后使我的ComboBox可编辑。当我这样做时我得到一个错误它有效,但我得到一个错误是缺少的东西。我还是Javafx的新手。这是代码。

我想要做的就是给用户一些固定的项目供选择,但首先如果用户从组合框中选择其他项目,那么组合框就变得可编辑了。从按钮设置组合框可编辑完美正常。我甚至做了一个影响组合框的方法。如果您了解JAVA,请查看代码。

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);

    }

}

这是错误

    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)

1 个答案:

答案 0 :(得分:2)

基本上,它是fx8中的一个错误:几乎所有的selectionModel都被严重破坏了。在您的代码中抛出NPE的确切原因有两个:

  1. 动作处理程序被调用两次,在第一次调用中,组合的值是“其他”,在第二次它是null(感谢@M leRutte找到它!) - 这是fx中的一个错误
  2. NPE第二次发生,因为您假设if (cb.getValue().equals("Other"))的值不为空 - 这样的检查可以更好地处理,即if ("Other".equals(cb.getValue()))
  3. 但是:即使使用反向检查,设置可编辑性也会在fx8中引发IndexOutOfBounds ...原因是MultipleSelectionModelBase的实现严重受损(在fx9中有所改进)。尽可能升级。

    如果不可能,即使在fx8中也有办法解决:看起来只有在弹出窗口打开时更改了editable属性时才会发生错误。所以我将逻辑改为

    • 听取combo的valueProperty并仅在未显示时更新可编辑
    • 将onHandler安装到onHidden,检查值并设置可编辑的

    仍有轻微的故障:

    • 将焦点转移到输入字段需要调整内部结构
    • 标记值(aks“Others”)未在textField中显示,懒得进一步挖掘,可能与null temporariy值相关

    修改后的例子:

    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);
        }
    }