我正在开发一个使用 java 和 javaFX 的项目，我需要知道是否有办法获得第一个 TiteledPane在Accordion 默认打开..

我的意思是当舞台加载时，第一个TiteledPane被选中并显示其内容无需任何用户干预。我尝试了所有建议的方法，但没有一个看起来像我想要的。正如我所见，官方文档或本网站或其他网站中也没有描述任何类似的内容。

另外:

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>

这里是个异常(exception):

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

这是我所依赖的文档中的文本。

public final void setExpandedPane(TitledPane value)

The expanded TitledPane that is currently visible. While it is technically possible to set the expanded pane to a value that is not in getPanes(), doing so will be treated by the skin as if expandedPane is null. If a pane is set as the expanded pane, and is subsequently removed from getPanes(), then expanded pane will be set to null, if possible. (This will not be possible if you have manually bound the expanded pane to some value, for example).

如果有什么不明白的地方欢迎评论。任何建议都会有所帮助..谢谢

最佳答案

对于那些想要在 FXML 而不是代码中包含默认展开 Pane 的人:

<Accordion expandedPane="$myPane">
    <panes>
      <TitledPane fx:id="myPane">
          ...
      </TitledPane>
      <TitledPane>
          ...
      </TitledPane>
    </panes>
</Accordion>

关于JavaFX:如何设置默认选择/打开的 TiteledPane，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33194517/