JavaFx：双向绑定，TableView中的选定值(JavaFx: Bidirectional Binding, selected value in TableView)

JavaFx：双向绑定，TableView中的选定值(JavaFx: Bidirectional Binding, selected value in TableView)

我需要一些帮助，我试图将模型中对象的属性与一些标签和文本字段绑定。

label1.textProperty().bind(myModel.getSelectedObject().getNameProperty());

在这种情况下， getSelectedObject()是TableView中的选定对象。 不知怎的，这不能按预期工作。 当模型的值发生变化时，标签不会改变。

我使用Bindings帮助类进行了修复以修复此问题：

label1.textProperty().bind(Bindings.select(myModel.getSelectedObject(), "name"));

只有使用Bindings帮助类，标签的文本才能正确绑定到对象的name-property。

现在我试图通过双向绑定获得相同的结果。 任何想法？

如果我像这样绑定它，它没有任何效果（与第一个代码剪切相同）

textField.textProperty().bindBidirectional(myModel.getSelectedObject().getNameProperty());

I need some help, im trying to bind properties of an object in my model with some labels and textfields.

label1.textProperty().bind(myModel.getSelectedObject().getNameProperty());

in this case getSelectedObject() is the selected Object in a TableView. Somehow this doesn't work as expected. When the model's value changes, the label doesn't change.

I mangaged to fix this issue with the Bindings help class:

label1.textProperty().bind(Bindings.select(myModel.getSelectedObject(), "name"));

Only with the Bindings help class the label's text gets binded correctly to the name-property of the object.

now im trying to get the same result with a bidirectional binding. Anyone any ideas?

If i bind it like this, it has no effect (same as first code-snipped)

textField.textProperty().bindBidirectional(myModel.getSelectedObject().getNameProperty());

最满意答案

SelectionModel ChangeListener启用切换绑定。 试试看。

tableView.getSelectionModel().selectedItemProperty().addListener((o, ov, nv) -> { if (ov != null) textField.textProperty().unbindBidirectional(ov.nameProperty()); if (nv != null) { textField.setDisable(false); textField.textProperty().bindBidirectional(nv.nameProperty()); } else { textField.setDisable(true); textField.setText(""); } });

注意：

如果从TableView的项目中删除了选定的项目，则使用删除的项目作为oldValue而不是null来调用此ChangeListner 。 因此无需关心删除列表项。

ChangeListener for SelectionModel enable to switch binding. Try it out.

tableView.getSelectionModel().selectedItemProperty().addListener((o, ov, nv) -> { if (ov != null) textField.textProperty().unbindBidirectional(ov.nameProperty()); if (nv != null) { textField.setDisable(false); textField.textProperty().bindBidirectional(nv.nameProperty()); } else { textField.setDisable(true); textField.setText(""); } });

NOTE:

In case selected item is removed from TableView's items, This ChangeListner is called with removed item as oldValue rather than null. So no needs to care removal of list item .