JavaFX Spinner拋出IllegalArgumentException：起始必須<=結尾

Question

我在我的JavaFX應用程序中使用了spinners。我已將listener添加到我的微調器中，以便始終從Spinner獲取更新的值。這Spinner是雙值微調。

lengthOverAllSpinner.getEditor().textProperty().addListener((observable, oldValue, newValue) -> { 
      try { 
       lengthOverAllSpinner.getValueFactory().setValue(Double.parseDouble(newValue)); 
      } catch (NumberFormatException e) { 
       lengthOverAllSpinner.getValueFactory().setValue(Double.parseDouble(oldValue)); 
      } 
     }); 

但是，當我試圖從GUI編輯我的微調（例如電流值是340.23），當我按空格鍵並直到例外以下的小數位被拋出刪除的價值，但我得到的最新值始終。不知道爲什麼這個例外即將到來。請幫助：

Exception in thread "JavaFX Application Thread" java.lang.IllegalArgumentException: The start must be <= the end 
at javafx.scene.control.TextInputControl.getText(TextInputControl.java:446) 
at javafx.scene.control.TextInputControl.updateContent(TextInputControl.java:564) 
at javafx.scene.control.TextInputControl.replaceText(TextInputControl.java:548) 
at javafx.scene.control.TextInputControl.deleteText(TextInputControl.java:496) 
at javafx.scene.control.TextInputControl.deletePreviousChar(TextInputControl.java:897) 
at com.sun.javafx.scene.control.skin.TextFieldSkin.deleteChar(TextFieldSkin.java:589) 
at com.sun.javafx.scene.control.behavior.TextFieldBehavior.deleteChar(TextFieldBehavior.java:198) 
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.deletePreviousChar(TextInputControlBehavior.java:311) 
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.callAction(TextInputControlBehavior.java:143) 
at com.sun.javafx.scene.control.behavior.BehaviorBase.callActionForEvent(BehaviorBase.java:218) 
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.callActionForEvent(TextInputControlBehavior.java:127) 
at com.sun.javafx.scene.control.behavior.BehaviorBase.lambda$new$75(BehaviorBase.java:135) 
at com.sun.javafx.scene.control.behavior.BehaviorBase$$Lambda$206/1978625466.handle(Unknown Source) 
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218) 
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80) 
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238) 
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191) 
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59) 
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58) 
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) 
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) 
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74) 
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54) 
at javafx.event.Event.fireEvent(Event.java:198) 
at javafx.scene.Scene$KeyHandler.process(Scene.java:3965) 
at javafx.scene.Scene$KeyHandler.access$1800(Scene.java:3911) 
at javafx.scene.Scene.impl_processKeyEvent(Scene.java:2040) 
at javafx.scene.Scene$ScenePeerListener.keyEvent(Scene.java:2502) 
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:197) 
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:147) 
at java.security.AccessController.doPrivileged(Native Method) 
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleKeyEvent$349(GlassViewEventHandler.java:228) 
at com.sun.javafx.tk.quantum.GlassViewEventHandler$$Lambda$459/610595104.get(Unknown Source) 
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:404) 
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(GlassViewEventHandler.java:227) 
at com.sun.glass.ui.View.handleKeyEvent(View.java:546) 
at com.sun.glass.ui.View.notifyKey(View.java:956) 
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) 
at com.sun.glass.ui.win.WinApplication.lambda$null$145(WinApplication.java:101) 
at com.sun.glass.ui.win.WinApplication$$Lambda$36/2058534881.run(Unknown Source) 
at java.lang.Thread.run(Thread.java:745) 

在此先感謝。

Answer 1

您的問題與此ISSE：JavaFX Textfield with listener gives: "java.lang.IllegalArgumentException: The start must be <= the end"

我不認爲它是建立在你的Spinner的編輯TextField的Spinner值是個好主意。

從editablePropertySpinner的文檔：

如果編輯爲真，將用戶輸入一旦用戶類型 接收，並按下回車鍵。此時輸入被傳遞給SpinnerValueFactory轉換器的String.Converter.fromString（String） 方法 。然後將此調用（類型T）的返回值發送到SpinnerValueFactory.setValue（Object）方法 。如果值爲 有效，則它將保持爲值。如果它無效，工廠的值 需要作出相應的反應並退出此更改。

因此，默認的工作方式是，只有按住Enter鍵才能編輯文本。在回車鍵上按TextField的文字被提交，並傳遞到的valueFactory的fromString方法。你可以在工廠像處理這種情況：

lengthOverAllSpinner.getValueFactory().setConverter(new StringConverter<Double>() { 
    private final DecimalFormat df = new DecimalFormat("#.####"); 

    @Override public String toString(Double value) { 
     // If the specified value is null, return a zero-length String 
     if (value == null) { 
      return ""; 
     } 

     return df.format(value); 
    } 

    @Override public Double fromString(String value) { 
     try { 
      // If the specified value is null or zero-length, return null 
      if (value == null) 
       return null; 

      value = value.trim(); 

      if (value.length() < 1) 
       return null; 

      // Perform the requested parsing 
      return df.parse(value).doubleValue(); 

     } catch (Exception ex) { 
      return 0.0; 
     } 
    } 
}); 

此外，您可以過濾輸入不使用TextFormatter在TextField接受非法字符：

TextFormatter<Object> textFormatter = new TextFormatter<>(c -> { 

    if (c.getText().matches("[^0-9.,]+") && !c.getText().isEmpty()) 
     return null; 

    SpinnerValueFactory.DoubleSpinnerValueFactory factory = (SpinnerValueFactory.DoubleSpinnerValueFactory) spinner.getValueFactory(); 
    try { 
     Double newVal = Double.parseDouble(c.getControlNewText()); 
     return (newVal >= factory.getMin() && factory.getMax() >= newVal) ? c : null; 
    } catch (Exception ex) { 
     c.setText("0.0"); 
     return c; 
    } 
}); 

spinner.getEditor().setTextFormatter(textFormatter); 

此格式將只接受數字和「。」和「，」字符。