JavaFX:如何设置默认选择/打开的TiteledPane

Question

我正在使用java和javaFX开发一个项目,我需要知道是否有办法TiteledPane 在默认情况下Accordion打开第一个..

我的意思是当加载舞台时,第一个TiteledPane被选中并且其内容在没有任何用户干预的情况下显示.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.

public final void setExpandedPane(TitledPane value)

目前可见的扩展TitledPane.虽然从技术上讲,可以将展开的窗格设置为不在getPanes()中的值,但是皮肤会将其视为expandPane为null.如果窗格设置为展开的窗格,并随后从getPanes()中删除,则展开的窗格将设置为null(如果可能).(例如,如果您已将展开的窗格手动绑定到某个值,则无法执行此操作).

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

Answer 1

对于那些想要在FXML中而不是在代码中包含默认扩展窗格的用户:

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

Answer 2

关于代码困难,强烈建议每次使用时刷新项目,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.

如果你仍然有一些代码问题,这个例子被验证:

@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章节都做备份会更好,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.