JavaFX組合框項目屬性綁定

我是JavaFX的新手，剛剛嘗試過屬性bindigs。它與StringProperty和BooleanProperty一起工作良好，但現在我必須將一些數據綁定到ComboBox。JavaFX組合框項目屬性綁定

這是死亡線。這是在控制器類的FXML：

comboBox.itemsProperty().bind(root.itemsProperty());

這裏是類根：

import javafx.beans.property.ObjectProperty; 
import javafx.beans.property.SimpleObjectProperty; 
import javafx.collections.ObservableList; 

public class SectionComboBox extends SectionControl{ 

    private final ObjectProperty<ObservableList> items = new SimpleObjectProperty<>(); 
    } 

    public ObservableList getItems() { 
     return items.get(); 
    } 

    public void setItems(ObservableList value) { 
     items.set(value); 
    } 

    public ObjectProperty itemsProperty() { 
     return items; 
    } 
}

錯誤日誌：

java.lang.NullPointerException 
at com.sun.javafx.scene.control.skin.ComboBoxListViewSkin.getIndexOfComboBoxValueInItemsList(ComboBoxListViewSkin.java:430) 
at com.sun.javafx.scene.control.skin.ComboBoxListViewSkin.updateDisplayNode(ComboBoxListViewSkin.java:376) 
at com.sun.javafx.scene.control.skin.ComboBoxListViewSkin.getDisplayNode(ComboBoxListViewSkin.java:232) 
at com.sun.javafx.scene.control.skin.ComboBoxBaseSkin.updateDisplayArea(ComboBoxBaseSkin.java:125) 
at com.sun.javafx.scene.control.skin.ComboBoxBaseSkin.computePrefHeight(ComboBoxBaseSkin.java:180) 
at javafx.scene.Parent.prefHeight(Parent.java:879) 
at javafx.scene.layout.Region.prefHeight(Region.java:1384) 
at javafx.scene.control.Control.computePrefHeight(Control.java:856) 
at javafx.scene.Parent.prefHeight(Parent.java:879) 
at javafx.scene.control.Control.prefHeight(Control.java:738) 
at javafx.scene.layout.Region.computeChildPrefAreaHeight(Region.java:1599) 
at javafx.scene.layout.AnchorPane.computeChildHeight(AnchorPane.java:296) 
at javafx.scene.layout.AnchorPane.layoutChildren(AnchorPane.java:327) 
at javafx.scene.Parent.layout(Parent.java:1018) 
at javafx.scene.Parent.layout(Parent.java:1028) 
at javafx.scene.Parent.layout(Parent.java:1028) 
at javafx.scene.Parent.layout(Parent.java:1028) 
at javafx.scene.Parent.layout(Parent.java:1028) 
at javafx.scene.Scene.layoutDirtyRoots(Scene.java:516) 
at javafx.scene.Scene.doLayoutPass(Scene.java:487) 
at javafx.scene.Scene.access$3900(Scene.java:170) 
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2186) 
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:363) 
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:461) 
at com.sun.javafx.tk.quantum.QuantumToolkit$9.run(QuantumToolkit.java:330) 
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) 
at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:17) 
at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:67) 
at java.lang.Thread.run(Thread.java:724)

有人可以幫助我如何我將它綁定相反，我錯過了什麼？

來源

2013-10-16 highwaycat

從昨天開始我就已經想通了。唯一的問題是，我忘記在將它綁定到ComboBox之前初始化ObservableList。所以，這是缺失的一行，fmo最開始：

root.setItems(FXCollections.observableArrayList());

來源

2013-10-17 15:24:09 highwaycat

JavaFX組合框項目屬性綁定

回答

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