问题描述
我希望在装有 FXMLoader
的场景中找到一个VBox节点,这要归功于 Node#lookup()
但是我得到以下异常:
I want to find a VBox node in a scene loaded with FXMLoader
thanks to Node#lookup()
but I get the following exception :
java.lang.ClassCastException:com.sun.javafx.scene.control.skin.SplitPaneSkin $ Content not not be转发给javafx.scene.layout.VBox
代码:
public class Main extends Application {
public static void main(String[] args) {
Application.launch(Main.class, (java.lang.String[]) null);
}
@Override
public void start(Stage stage) throws Exception {
AnchorPane page = (AnchorPane) FXMLLoader.load(Main.class.getResource("test.fxml"));
Scene scene = new Scene(page);
stage.setScene(scene);
stage.show();
VBox myvbox = (VBox) page.lookup("#myvbox");
myvbox.getChildren().add(new Button("Hello world !!!"));
}
}
fxml文件:
<AnchorPane id="AnchorPane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns:fx="http://javafx.com/fxml" >
<children>
<SplitPane dividerPositions="0.5" focusTraversable="true" prefHeight="400.0" prefWidth="600.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<items>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0" />
<VBox fx:id="myvbox" prefHeight="398.0" prefWidth="421.0" />
</items>
</SplitPane>
</children>
</AnchorPane>
我想知道:
1.为什么查找方法返回 SplitPaneSkin $ Content
而不是 VBox
?
2.如何获得 VBox
以另一种方式?
I would like to know :
1. Why lookup method return a SplitPaneSkin$Content
and not a VBox
?
2. How I can get the VBox
in another manner ?
提前致谢
推荐答案
-
SplitPane将所有项目放在单独的堆栈窗格中(想象为
SplitPaneSkin $ Content
)。由于未知原因,FXMLLoader为它们分配与root child相同的id。您可以通过下一个实用方法获得所需的VBox:
SplitPane puts all items in separate stack panes (fancied as
SplitPaneSkin$Content
). For unknown reason FXMLLoader assign them the same id as root child. You can get VBox you need by next utility method:
public <T> T lookup(Node parent, String id, Class<T> clazz) {
for (Node node : parent.lookupAll(id)) {
if (node.getClass().isAssignableFrom(clazz)) {
return (T)node;
}
}
throw new IllegalArgumentException("Parent " + parent + " doesn't contain node with id " + id);
}
并使用下一个方式:
VBox myvbox = lookup(page, "#myvbox", VBox.class);
myvbox.getChildren().add(new Button("Hello world !!!"));
你可以使用并添加自动填充字段:
you can use Controller and add autopopulated field:
@FXML
VBox myvbox;
这篇关于JavaFX 2.0 + FXML - 奇怪的查找行为的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!