fxml组合框，将选定的值获取到javafx中 [英] fxml combobox, get the selected value into javafx

问题描述

我如何捕获fxml组合框的选定值并将其实现到javafx类中？

我给组合框fx：idsample具有onAction =＃test的按钮并尝试.getValue和.getPromptText。

  @FXML private ComboBox< String>样品; 
 
 @FXML protected void test（ActionEvent event）{
 String output =（String）Sample.getValue（）; 
 System.out.println（output）; 
 
 String output =（String）Sample.getPromptText（）; 
 System.out.println（output）; 
} 
  

如果我尝试运行它，我得到一个错误：

  java.lang.RuntimeException：java.lang.reflect.InvocationTargetException 
 at javafx.fxml.FXMLLoader $ ControllerMethodEventHandler.handle（FXMLLoader.java ：1440）
 at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent（CompositeEventHandler.java:69）
 at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent（EventHandlerManager.java:217）
 at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent（EventHandlerManager.java:170）
 at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent（CompositeEventDispatcher.java:38）
 at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent（BasicEventDispatcher.java:37）
 at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent（EventDispatchChainImpl.java:92）
 at com.sun。 javafx.event.BasicEventDispatcher.dispatchEvent（BasicEventDispatcher.java:35）
 at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent（EventDispatchChainImpl.java:92）
 at com.sun.javafx.event。 BasicEventDispatcher.dispatchEvent（BasicEventDispatcher.java:35）
 at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent（EventDispatchChainImpl.java:92）
 at com.sun.javafx.event.EventUtil.fireEventImpl EventUtil.java:53）
 at com.sun.javafx.event.EventUtil.fireEvent（EventUtil.java:28）
 at javafx.event.Event.fireEvent（Event.java:171）
 at javafx.scene.Node.fireEvent（Node.java:6863）
 at javafx.scene.control.Button.fire（Button.java:179）
 at com.sun.javafx.scene .control.behavior.ButtonBehavior.mouseReleased（ButtonBehavior.java:193）
 at com.sun.javafx.scene.control.skin.SkinBase $ 4.handle（SkinBase.java:336）
 at com。 sun.javafx.scene.control.skin.SkinBase $ 4.handle（SkinBase.java:329）
 at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent（CompositeEventHandler.java:64）
 at com .sun.javafx.event.EventHandlerManager.dispatchBubblingEvent（EventHandlerManager.java:217）
 at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent（EventHandlerManager.java:170）
 at com.sun.javafx .event.CompositeEventDispatcher.dispatchBubblingEvent（CompositeEventDispatcher.java:38）
 at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent（BasicEventDispatcher.java:37）
 at com.sun.javafx.event.EventDispatchChainImpl .dispatchEvent（EventDispatchChainImpl.java:92）
 at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent（BasicEventDispatcher.java:35）
 at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent（EventDispatchChainImpl .java：92）
 at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent（BasicEventDispatcher.java:35）
 at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent（EventDispatchChainImpl.java:92 ）
 at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent（BasicEventDispatcher.java:35）
 at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent（EventDispatchChainImpl.java:92）
 at com.sun.javafx.event.EventUtil.fireEventImpl（EventUtil.java:53）
 at com.sun.javafx.event.EventUtil.fireEvent（EventUtil.java:33）
在javafx。 event.Event.fireEvent（Event.java:171）
在javafx.scene.Scene $ MouseHandler.process（Scene.java:3324）
在javafx.scene.Scene $ MouseHandler.process（Scene。 java：3164）
在javafx.scene.Scene $ MouseHandler.access $ 1900（Scene.java:3119）
在javafx.scene.Scene.impl_processMouseEvent（Scene.java:1559）
 javafx.scene.Scene $ ScenePeerListener.mouseEvent（Scene.java:2261）
 at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent（GlassViewEventHandler.java:228）
 at com.sun。 glass.ui.View.handleMouseEvent（View.java:528）
 at com.sun.glass.ui.View.notifyMouse（View.java:922）
 at com.sun.glass.ui。 win.WinApplication._runLoop（Native方法）
 at com.sun.glass.ui.win.WinApplication.access $ 100（WinApplication.java:29）
 at com.sun.glass.ui.win。 WinApplication $ 3 $ 1.run（WinApplication.java:73）
在java.lang.Thread.run（Thread.java:722）
导致：java.lang.reflect.InvocationTargetException 
 at sun.reflect.NativeMethodAccessorImpl.invoke0（Native方法）
 at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:57）
 at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）
 at java.lang.reflect.Method.invoke（Method.java:601）
 at javafx.fxml.FXMLLoader $ ControllerMethodEventHandler.handle（FXMLLoader.java:1435）
 ... 45更多
 Caused by：java.lang.NullPointerException 
 at TW_JAVAFX_Undecorator.ButtonController.pruefen（ButtonController.java:60）
 ...另外50个
  

提前感谢

Zombie

解决方案

我认为你的问题中的代码应该工作，只要在代码中的combobox标识符的情况下匹配你的fxml fx：id 。

我修改了此 JavaFX fxml组合框选择演示app 添加一个带有onAction方法的按钮，使用comboBox getValue（）方法从组合框中检索值，并且对我来说工作正常。 p>

检查事情的情况，我注意到你说 fx：id 是 / code>，但在你的代码中你使用 Sample - 并且这些情况必须匹配，否则fxml加载器不会将节点注入到控制器中。很难说如果 NullPointerException 在您的代码中与您的组合框值检索问题相关，因为您不说 TW_JAVAFX_Undecorator.ButtonController.pruefen（ButtonController.java:60）中的代码是或提供完整的可执行代码来复制该问题。

how can i catch the selected value of a fxml combobox and implement it into a javafx class?

i gave the combobox the fx:id "sample" and created a button with onAction="#test" and tried .getValue and .getPromptText.

@FXML private ComboBox<String> Sample;

@FXML protected void test( ActionEvent event ) { 
String output = (String) Sample.getValue();
System.out.println(output);

String output = (String) Sample.getPromptText();
System.out.println(output);
}

If i try to run it i get an error:

java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1440)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:69)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:28)
    at javafx.event.Event.fireEvent(Event.java:171)
    at javafx.scene.Node.fireEvent(Node.java:6863)
    at javafx.scene.control.Button.fire(Button.java:179)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:193)
    at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:336)
    at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:329)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:64)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
    at javafx.event.Event.fireEvent(Event.java:171)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3324)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3164)
    at javafx.scene.Scene$MouseHandler.access$1900(Scene.java:3119)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1559)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2261)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:228)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:528)
    at com.sun.glass.ui.View.notifyMouse(View.java:922)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:29)
    at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:73)
    at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1435)
    ... 45 more
Caused by: java.lang.NullPointerException
    at TW_JAVAFX_Undecorator.ButtonController.pruefen(ButtonController.java:60)
    ... 50 more

Thanks in advance

Zombie

解决方案

I think the code you have in your question should work as long as the case of the combobox identifier in the code matches that of your fxml fx:id.

I modified this JavaFX fxml combo box selection demonstration app to add a button with an onAction method to retrieve a value from the combo box using the comboBox getValue() method and it worked fine for me.

Check the case of things, I notice that you say the fx:id is sample, yet in your code you use Sample - and the cases must match otherwise the fxml loader won't inject the node into your controller correctly.

Hard to say if the NullPointerException in your code is related to your combo box value retrieval issue as you don't say what the code at TW_JAVAFX_Undecorator.ButtonController.pruefen(ButtonController.java:60) is or provide full executable code to replicate the issue.

这篇关于fxml组合框，将选定的值获取到javafx中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IT屋！