使用JavaFX TreeView拖放

Question

我已按照本论坛其他主题的建议实现了拖放功能。我在cellFactory上有一个TreeView，并在单元格上设置了事件。

tvProject.setCellFactory(new Callback<TreeView<PlanningItem>, TreeCell<PlanningItem>>() {
        @Override
        public PlanningCheckBoxTreeCell call(TreeView<PlanningItem> siTreeView) {
            final PlanningCheckBoxTreeCell source = new PlanningCheckBoxTreeCell();
            final PlanningCheckBoxTreeCell target = new PlanningCheckBoxTreeCell();

            source.setOnDragDetected(new EventHandler<MouseEvent>() {
                public void handle(MouseEvent event) {
                    /* drag was detected, start drag-and-drop gesture */
                    System.out.println("onDragDetected");

                    /* allow any transfer mode */
                    Dragboard db = source.startDragAndDrop(TransferMode.ANY);

                    /* put a string on dragboard */
                    ClipboardContent content = new ClipboardContent();
                    content.putString(source.getText());
                    db.setContent(content);

                    event.consume();
                }
            });

            target.setOnDragOver(new EventHandler<DragEvent>() {
                public void handle(DragEvent event) {
                    /* data is dragged over the target */
                    System.out.println("onDragOver");

                    ...

                    event.consume();
                }
            });

setOnDragDetected根据需要执行/命中，但其他所有事件均未执行（我没有在此处发布所有事件：setOnDragOver，setOnDragEntered，setOnDragExited，{{ 1}}，setOnDragDropped）。 setOnDragDone是树单元的自定义实现，如下所示：

PlanningCheckBoxTreeCell

更新 public class PlanningCheckBoxTreeCell extends CheckBoxTreeCell<PlanningItem> { public PlanningCheckBoxTreeCell() { } @Override public void updateItem(PlanningItem item, boolean empty) { super.updateItem(item, empty); if (!empty) { setText(null); } } } ：

PlanningItem

更新 MCVE：

    package at.v2c2.testplaygroundui;

import java.io.Serializable;


public class PlanningItem implements Serializable {

    private static final long serialVersionUID = 1L;
    private Double scene = null;
    private Integer path = null;
    private String move = null;

    /**
     * @return the scene
     */
    public Double getScene() {
        return scene;
    }

    /**
     * @param scene the scene to set
     */
    private void setScene(Double scene) {
        this.scene = scene;
    }

    /**
     * @return the path
     */
    public Integer getPath() {
        return path;
    }

    /**
     * @param path the path to set
     */
    private void setPath(Integer path) {
        this.path = path;
    }

    /**
     * @return the move
     */
    public String getMove() {
        return move;
    }

    /**
     * @param move the move to set
     */
    private void setMove(String move) {
        this.move = move;
    }

    public PlanningItem(Object item) {
        super();
        if (item instanceof Double) {
            setScene((Double) item);
        } else if (item instanceof Integer) {
            setPath((Integer) item);
        } else if (item instanceof String) {
            setMove((String) item);
        }
    }

}

预先感谢