JavaFX：如何设置默认选择/打开的TiteledPane

FX开发一个项目,我需要知道是否有办法让Accordion中的第一个TiteledPane默认打开.

我的意思是在加载舞台时,会选择第一个TiteledPane并显示其内容而无需任何用户干预.我尝试了所有建议的方法,但没有人看起来像我想要的.正如我所看到的还没有在官方文档中描述或在本网站或其他地方给出的一样.

此外：

这是我的方法:(代码java和FXML)

@FXML
private Accordion accord_pane;
@FXML
private TitledPane pane_ara,pane_sci,pane_soc,pane_art,pane_spo,pane_fra,pane_ang;

...

pane_ara.setText("TitledPane A");
pane_sci.setText("TitledPane B");

accord_pane.setExpandedPane(pane_ara);

<Accordion fx:id="accord_pane" layoutX="20.0" layoutY="100.0" prefHeight="400.0" prefWidth="680.0">
                  <panes>
                    <TitledPane fx:id="pane_ara" animated="false">
                         <content>
                            <Pane prefHeight="200.0" prefWidth="200.0">
                               <children>
                                  <ImageView fx:id="img_unit_ara" fitHeight="250.0" fitWidth="650.0" layoutX="15.0" layoutY="15.0" pickOnBounds="true" preserveRatio="true">
                                     <image>
                                        <Image url="@temp_5.png" />
                                     </image>
                                  </ImageView>
                               </children>
                            </Pane>
                         </content>
                    </TitledPane>
                      <TitledPane fx:id="pane_sci" animated="false">
                         <content>
                            <Pane prefHeight="200.0" prefWidth="200.0">
                               <children>
                                  <ImageView fx:id="img_unit_sci" fitHeight="190.0" fitWidth="650.0" layoutX="15.0" layoutY="15.0" pickOnBounds="true" preserveRatio="true">
                                     <image>
                                        <Image url="@temp_3.png" />
                                     </image>
                                  </ImageView>
                               </children>
                            </Pane>
                         </content>
                      </TitledPane>
                     </panes>
                   </Accordion>

这是例外：

javafx.fxml.LoadException: 
/C:/Users/Malek%20Boubakri/Google%20Drive/workspace/Sirat/bin/vue/Enseignant.fxml
at javafx.fxml.FXMLLoader.constructLoadException(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.load(Unknown Source)
at vue.Enseignant.start(Enseignant.java:18)
at vue.Index.stageCtrlHandler(Index.java:85)
at controleur.MenuCtrl.click_btn(MenuCtrl.java:69)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.reflect.misc.Trampoline.invoke(Unknown Source)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.reflect.misc.MethodUtil.invoke(Unknown Source)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(Unknown Source)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at javafx.event.Event.fireEvent(Unknown Source)
at javafx.scene.Scene$ClickGenerator.postProcess(Unknown Source)
at javafx.scene.Scene$ClickGenerator.access$8100(Unknown Source)
at javafx.scene.Scene$MouseHandler.process(Unknown Source)
at javafx.scene.Scene$MouseHandler.access$1500(Unknown Source)
at javafx.scene.Scene.impl_processMouseEvent(Unknown Source)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$350(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$$Lambda$165/775736639.get(Unknown Source)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
at com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
at com.sun.glass.ui.View.notifyMouse(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$145(Unknown Source)
at com.sun.glass.ui.win.WinApplication$$Lambda$36/2117255219.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
    at controleur.EnsCtrl.initialize(EnsCtrl.java:301)
    ... 54 more

这是我依赖的文档中的文本.

如果有任何不清楚的地方请评论.任何建议都会有所帮助.谢谢

关于代码困难,强烈建议每次处理时刷新项目,然后从javaFX场景构建器保存FXML文件,因为eclipse不会自动执行此操作.

如果您仍然遇到一些代码问题,则会验证此示例：

@FXML
private Accordion accord;
@FXML
private TitledPane pane1,pane2;

//codes in controller.intialize()
...
    pane1.setText("TitledPane A");
    pane2.setText("TitledPane B");
    accord.setExpandedPane(pane1);

关于你在评论中提到的云问题,因为我知道将工作区放在谷歌驱动器文件夹中是没有害处的.如果你每次完成代码的一部分都做备份会更好,因为有时驱动器崩溃当他尝试加载另一个程序已经使用过的文件时.