javaFX树结构treeview使用

//---------------------------------------------------在JavaFX Scene Builder里已经加了widget，设置了fx:id

 1 @FXML
 2     private TreeView<String> tv;
 3 @Override
 4     public void initialize(URL location, ResourceBundle resources) {
 5         // TODO Auto-generated method stub
 6         initTreeView();
 7     }
 8     private void initTreeView(){
 9         TreeItem<String> item = new TreeItem<>("跟节点");
10         tv.setRoot(item);
11         item.setExpanded(false);
12         TreeItem<String> i1 = new TreeItem<>("电影");
13         TreeItem<String> i2 = new TreeItem<>("音乐");
14         TreeItem<String> i3 = new TreeItem<>("游戏");
15         item.getChildren().addAll(i1,i2,i3);
16         TreeItem<String> i4 = new TreeItem<>("荡寇风云");
17         TreeItem<String> i5 = new TreeItem<>("变形金刚5");
18         i1.setExpanded(false);
19         i1.getChildren().addAll(i4,i5);
20
21     }