JavaFX单选按钮定向绑定

时间:2019-02-23 09:36:50

标签: java javafx

对于Javafx来说还是新手,我想对单选按钮执行定向绑定

我的fxml中有

  <fx:define>
          <ToggleGroup fx:id="version_selection" />                  
  </fx:define> 
  <RadioButton toggleGroup="$version_selection" ............> 
  <RadioButton toggleGroup="$version_selection" ............> 

在我的控制器中,我想绑定所选切换组的值。有了文本框,一切都变得简单

 @FXML
TextField name;

@FXML
private ToggleGroup version_selection;

  name.textProperty().bindBidirectional(model.field5Property());

模型是我的具有SimpleStringValue属性的类

我如何绑定切换组,因为它没有作为文本字段的文本属性

1 个答案:

答案 0 :(得分:2)

即使您的模型中有ObjectProperty<Toggle>,也无法建立双向绑定,因为ToggleGroup.selectedToggle是只读的。您需要通过在ToggleGroup.selectedToggle属性和model属性中添加一个侦听器并更新该属性(而不是更改源)来解决此问题。

使用Map<String, Toggle>将文本转换为要选择的切换。下面的示例使用TextField来确定属性,而不是模型属性来演示行为:输入RadioButton的文本进行选择,然后将其选中。

@Override
public void start(Stage primaryStage) throws IOException {

    ToggleGroup group = new ToggleGroup();
    VBox vbox = new VBox();

    for (char c = 'a'; c <= 'f'; c++) {
        RadioButton radio = new RadioButton(Character.toString(c));
        radio.setToggleGroup(group);
        vbox.getChildren().add(radio);
    }

    TextField input = new TextField();
    vbox.getChildren().add(input);

    // create map mapping from text to corresponding toggle
    Map<String, Toggle> map = new HashMap<>();      
    for (Toggle t : group.getToggles()) {
        map.put(((RadioButton) t).getText(), t);
    }

    StringProperty property = input.textProperty();

    InvalidationListener listener = new InvalidationListener() {

        // flag preventing circular updating
        boolean updating = false;

        @Override
        public void invalidated(Observable observable) {
            if (!updating) {
                updating = true;

                if (observable == group.selectedToggleProperty()) {
                    // change as result of user interaction with RadioButton

                    // update property
                    RadioButton selectedToggle = (RadioButton) group.getSelectedToggle();
                    property.set(selectedToggle == null ? "" : selectedToggle.getText());
                } else {
                    // change as result of updating the property

                    // select corresponding toggle
                    Toggle toggleToSelect = map.get(property.get());
                    group.selectToggle(toggleToSelect);
                }

                updating = false;
            }
        }

    };

    property.addListener(listener);
    group.selectedToggleProperty().addListener(listener);

    Scene scene = new Scene(vbox);
    primaryStage.setScene(scene);
    primaryStage.show();
}