我LiveList
用来将组的孩子绑定到包含孩子数据的列表。这是一个例子:
public class Main extends Application {
@Override
public void start(Stage primaryStage) {
ObservableList<Integer> intList = FXCollections.observableArrayList();
LiveList<Circle> circleList = LiveList.map(intList, i -> {
System.out.println("in");
return new Circle(i);
});
Group group = new Group();
Bindings.bindContent(group.getChildren(), circleList);
intList.add(2);
intList.clear();
}
public static void main(String[] args) {
launch(args);
}
}
我的问题是绑定列表中的每个更改intList
都会更新两次,这会创建比需要更多的对象。运行代码给出:
in
in
Exception in thread "JavaFX Application Thread" java.lang.IllegalArgumentException: Children: duplicate children added: parent = Group@68887c42
at javafx.scene.Parent$2.onProposedChange(Parent.java:454)
at com.sun.javafx.collections.VetoableListDecorator$VetoableSubListDecorator.clear(VetoableListDecorator.java:529)
at com.sun.javafx.binding.ContentBinding$ListContentBinding.onChanged(ContentBinding.java:114)
at org.reactfx.collection.ChangeListenerWrapper.onChange(LiveList.java:439)
at org.reactfx.collection.ChangeListenerWrapper.onChange(LiveList.java:417)
at org.reactfx.util.ListNotifications.lambda$takeHead$0(NotificationAccumulator.java:317)
at org.reactfx.ObservableBase.notifyObservers(ObservableBase.java:68)
at org.reactfx.ObservableBase.notifyObservers(ObservableBase.java:57)
at org.reactfx.collection.MappedList.sourceChanged(MappedList.java:41)
at org.reactfx.collection.LiveList.lambda$observeQuasiChanges$7(LiveList.java:256)
at com.sun.javafx.collections.ListListenerHelper$SingleChange.fireValueChangedEvent(ListListenerHelper.java:164)
at com.sun.javafx.collections.ListListenerHelper.fireValueChangedEvent(ListListenerHelper.java:73)
at javafx.collections.ObservableListBase.fireChange(ObservableListBase.java:233)
at javafx.collections.ListChangeBuilder.commit(ListChangeBuilder.java:482)
at javafx.collections.ListChangeBuilder.endChange(ListChangeBuilder.java:541)
at javafx.collections.ObservableListBase.endChange(ObservableListBase.java:205)
at com.sun.javafx.collections.ObservableListWrapper.clear(ObservableListWrapper.java:157)
at test1.Main.start(Main.java:27)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
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)
我希望对于其中的每个元素,该组的孩子中intList
都会有一个Circle
。为什么会发生这种情况,我怎样才能让它正常工作?