javafx - 从 TreeView 中删除节点

Question

我想用上下文菜单创建这个简单的 javaFX TreeView 示例，它可以从树中删除节点:

public class TreeViewSample extends Application {

    private final Node rootIcon = new ImageView(
        new Image(getClass().getResourceAsStream("folder_16.png"))
    );

    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Tree View Sample");        

        TreeItem<String> rootItem = new TreeItem<String> ("Inbox", rootIcon);
        rootItem.setExpanded(true);
        for (int i = 1; i < 6; i++) {
            TreeItem<String> item = new TreeItem<String> ("Message" + i);            
            rootItem.getChildren().add(item);
        }        
        TreeView<String> tree = new TreeView<String> (rootItem);        
        StackPane root = new StackPane();
        root.getChildren().add(tree);
        primaryStage.setScene(new Scene(root, 300, 250));
        primaryStage.show();
    }
}

我测试了这个上下文菜单以删除右键单击选定的节点:

final ContextMenu contextMenu = new ContextMenu();
        MenuItem item1 = new MenuItem("About");
        item1.setOnAction(new EventHandler<ActionEvent>()
        {
            @Override
            public void handle(ActionEvent e)
            {
                System.out.println("About");
            }
        });
        MenuItem item2 = new MenuItem("Preferences");
        item2.setOnAction(new EventHandler<ActionEvent>()
        {
            @Override
            public void handle(ActionEvent e)
            {
                System.out.println("Preferences");
            }
        });
        MenuItem item3 = new MenuItem("Remove");
        item3.setOnAction(new EventHandler<ActionEvent>()
        {
            @Override
            public void handle(ActionEvent e)
            {

                DynamicTreeNodeModel c = treeView.getSelectionModel().getSelectedItem().getValue();
                boolean remove = treeView.getSelectionModel().getSelectedItem().getChildren().remove(c);
                System.out.println("Remove");
            }
        });
        contextMenu.getItems().addAll(item1, item2, item3);

        treeView.setContextMenu(contextMenu);

由于某种原因，代码不起作用。你能帮我解决这个问题吗？

Answer 1

您正在尝试从其自己的子节点中删除所选节点。因为它不存在那里，所以什么都不会发生。您需要从其父节点的子节点中删除所选节点。

    MenuItem item3 = new MenuItem("Remove");
    item3.setOnAction(new EventHandler<ActionEvent>() {
        @Override
        public void handle(ActionEvent e) {
            TreeItem c = (TreeItem)treeView.getSelectionModel().getSelectedItem();
            boolean remove = c.getParent().getChildren().remove(c);
            System.out.println("Remove");
        }
    });