Graphics JavaFX TreeView:setGraphic()用于不同级别的treeItem
我正在创建一个树视图,对于不同层次的树结构应该有不同的图形。它是一个三层结构,根隐藏在其中 可扩展节点的图形: 叶节点的图形: 只是hBox中的一个标签 这是我到目前为止尝试过的,但我得到一个nullPointerException,基本上是说getTreeView为null: CustomTreeCellFactoryGraphics JavaFX TreeView:setGraphic()用于不同级别的treeItem,graphics,javafx,treeview,Graphics,Javafx,Treeview,我正在创建一个树视图,对于不同层次的树结构应该有不同的图形。它是一个三层结构,根隐藏在其中 可扩展节点的图形: 叶节点的图形: 只是hBox中的一个标签 这是我到目前为止尝试过的,但我得到一个nullPointerException,基本上是说getTreeView为null: CustomTreeCellFactory public final class CustomTreeCellFactory extends TreeCell<String>{ private TextFi
public final class CustomTreeCellFactory extends TreeCell<String>{
private TextField textField;
private HBox hBox;
public CustomTreeCellFactory(){
super();
if (getTreeView()==null){
System.out.println("Her er problem");
}
if (getTreeView().getTreeItemLevel(getTreeItem())==1){
try {
hBox = (HBox) FXMLLoader.load(getClass().getResource("/Views/TreCell.fxml"));
} catch (IOException e) {
System.out.println("This didn't work");
e.printStackTrace();
}
}
else if (getTreeView().getTreeItemLevel(getTreeItem())==2){
try {
hBox = (HBox) FXMLLoader.load(getClass().getResource("/Views/TreCellLowestLevel.fxml"));
} catch (IOException e) {
System.out.println("This didn't work");
e.printStackTrace();
}
}
}
TreeView<String> tree = (TreeView) parent.getChildren().get(0);
tree.setRoot(root);
tree.setShowRoot(false);
tree.setEditable(true);
tree.setCellFactory(new Callback<TreeView<String>, TreeCell<String>>() {
@Override
public TreeCell<String> call(TreeView<String> param) {
return new CustomTreeCellFactory();
}
});
公共最终类CustomTreeCellFactory扩展了TreeCell{
私有文本字段文本字段;
私人HBox;
公共CustomTreeCellFactory(){
超级();
如果(getTreeView()==null){
System.out.println(“她的er问题”);
}
如果(getTreeView().getTreeItemLevel(getTreeItem())==1){
试一试{
hBox=(hBox)fxmloader.load(getClass().getResource(“/Views/TreCell.fxml”);
}捕获(IOE异常){
System.out.println(“这不起作用”);
e、 printStackTrace();
}
}
else if(getTreeView().getTreeItemLevel(getTreeItem())==2){
试一试{
hBox=(hBox)fxmloader.load(getClass().getResource(“/Views/trecellllowestlevel.fxml”);
}捕获(IOE异常){
System.out.println(“这不起作用”);
e、 printStackTrace();
}
}
}
设置单元格工厂的代码片段
public final class CustomTreeCellFactory extends TreeCell<String>{
private TextField textField;
private HBox hBox;
public CustomTreeCellFactory(){
super();
if (getTreeView()==null){
System.out.println("Her er problem");
}
if (getTreeView().getTreeItemLevel(getTreeItem())==1){
try {
hBox = (HBox) FXMLLoader.load(getClass().getResource("/Views/TreCell.fxml"));
} catch (IOException e) {
System.out.println("This didn't work");
e.printStackTrace();
}
}
else if (getTreeView().getTreeItemLevel(getTreeItem())==2){
try {
hBox = (HBox) FXMLLoader.load(getClass().getResource("/Views/TreCellLowestLevel.fxml"));
} catch (IOException e) {
System.out.println("This didn't work");
e.printStackTrace();
}
}
}
TreeView<String> tree = (TreeView) parent.getChildren().get(0);
tree.setRoot(root);
tree.setShowRoot(false);
tree.setEditable(true);
tree.setCellFactory(new Callback<TreeView<String>, TreeCell<String>>() {
@Override
public TreeCell<String> call(TreeView<String> param) {
return new CustomTreeCellFactory();
}
});
TreeView tree=(TreeView)parent.getChildren().get(0);
树根;
tree.setShowRoot(false);
tree.setEditable(true);
setCellFactory(新回调(){
@凌驾
公共TreeCell调用(TreeView参数){
返回新的CustomTreeCellFactory();
}
});
我发现了问题所在
当树视图被设置时,我试图做的事情需要在更新方法中完成
以下是解决问题的代码:
**Constructor**
public CustomTreeCellFactory(){
try {
hBox = (HBox) FXMLLoader.load(getClass().getResource("/Views/TreCell.fxml"));
} catch (IOException e) {
System.out.println("This didn't work");
e.printStackTrace();
}
try {
hBoxLeaf = (HBox) FXMLLoader.load(getClass().getResource("/Views/TreCellLowestLevel.fxml"));
} catch (IOException e) {
System.out.println("This didn't work");
e.printStackTrace();
}
}
更新方法
@Override
public void updateItem(String item, boolean empty) {
super.updateItem(item, empty);
if (item != null) {
if (getTreeView().getTreeItemLevel(getTreeItem())==1) {
setGraphic(this.hBox);
}else if (getTreeView().getTreeItemLevel(getTreeItem())==2){
setGraphic(this.hBoxLeaf);
}
} else {
setGraphic(null);
}
}