如何将JavaFX Label绑定到ListView中的选定项目

Question

我有一个装满POJO的ListView,并希望GUI中有一个标签来显示所选项目的信息.

我的POJO看起来像这样:

class Customer {
  private String name;
  ...
  public String getName() {
  return name; 
  }

现在,当用户从列表中选择客户时,我希望在标签中显示所选客户的名称.

显然我不能name直接绑定,因为它不是一个Property.(而且我不想String用StringProperty-objects 替换我的客户,因为SimpleStringProperty它不是serializable,我需要Customer通过RMI转移.)

我试着BeanPathAdapter从JFXtras(这看起来真的不错的方式)是这样的:

    BeanPathAdapter<MultipleSelectionModel> customerBeanPathAdapter;
    customerBeanPathAdapter = new BeanPathAdapter<>(lstCustomers.getSelectionModel());
    customerBeanPathAdapter.bindBidirectional("selectedItem.name", lblCustomerName.textProperty());

但是这个解决方案只给我一个例外:

...
Caused by: java.lang.IllegalArgumentException: Unable to resolve accessor getSelectedItem
at jfxtras.labs.scene.control.BeanPathAdapter$FieldHandle.buildAccessor(BeanPathAdapter.java:3062)
at jfxtras.labs.scene.control.BeanPathAdapter$FieldHandle.buildAccessorWithLikelyPrefixes(BeanPathAdapter.java:3022)
at jfxtras.labs.scene.control.BeanPathAdapter$FieldHandle.updateMethodHandles(BeanPathAdapter.java:2986)
at jfxtras.labs.scene.control.BeanPathAdapter$FieldHandle.<init>(BeanPathAdapter.java:2977)
at jfxtras.labs.scene.control.BeanPathAdapter$FieldBean.performOperation(BeanPathAdapter.java:1348)
at jfxtras.labs.scene.control.BeanPathAdapter$FieldBean.performOperation(BeanPathAdapter.java:1186)
at jfxtras.labs.scene.control.BeanPathAdapter.bindBidirectional(BeanPathAdapter.java:567)
at jfxtras.labs.scene.control.BeanPathAdapter.bindBidirectional(BeanPathAdapter.java:369)
at at.gs1.sync.qm.client.gui.MainWindowController.initialize(MainWindowController.java:61)
... 22 more
Caused by: java.lang.IllegalAccessException: symbolic reference class is not public: class javafx.scene.control.ListView$ListViewBitSetSelectionModel, from jfxtras.labs.scene.control.BeanPathAdapter$FieldHandle
at java.lang.invoke.MemberName.makeAccessException(MemberName.java:512)
at java.lang.invoke.MethodHandles$Lookup.checkSymbolicClass(MethodHandles.java:1113)
at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1094)
at java.lang.invoke.MethodHandles$Lookup.findVirtual(MethodHandles.java:626)
at jfxtras.labs.scene.control.BeanPathAdapter$FieldHandle.buildAccessor(BeanPathAdapter.java:3049)
... 30 more

所以我希望有一个更好的解决方案,而不是lstCustomers.getSelectionModel().selectedItemProperty().addListener(...)手动使用和处理标签的数量.

Answer 1

我认为，相对于我之前给出的解决方案，更好的解决方案是使用您尝试过的 BeanPathAdapter 。
但是 BeanPathAdapter 需要添加以下属性：

private final ObjectProperty<B>  beanProp = new SimpleObjectProperty<>();
{
    beanProp.addListener( new ChangeListener<B>()
    {
        @Override
        public void changed( ObservableValue<? extends B> ob, B oldVal, B newVal )
        {
            setBean( newVal );
        }
    } );
}

public ObjectProperty<B> beanProperty()
{
    return beanProp; 
}

然后在您的代码中您需要以下内容：

BeanPathAdapter<Customer>  custBean;
custBean = new BeanPathAdapter<>( new Customer() );   // empty or any customer
custBean.bindBidirectional( "name", label.textProperty() );
custBean.beanProperty().bind( listview.getSelectionModel().selectedItemProperty() );