堆棧內存溢出
  簡體   English   中英

在JavaFX的GridPane中從TextArea獲取文本

[英]Getting text from TextArea in a GridPane in JavaFX

 原文  2016-09-24 01:41:13  7   1    java/ javafx

問題描述

我有一個項目，詢問用戶使用什么類型的電子設備來告訴他們需要多少個太陽能電池板和電池。

為了收集信息，我使用了具有三列的gridPane，其中有TextArea和可變數量的行。 我需要在gridPane的第二行和第三行中收集信息。

我使用以下方法，該方法是我在這里問到的另一個問題所發現的。 

private void calculer(ActionEvent event)
{
    double ampApp = 0;
    double heureApp = 0;
    double wattTotal = 0;
    double nbJourAuto;
    double heureSoleil;
    int nbPanneau;
    int nbBatterie;
    String stringTemp;

    for(int i =1; i < rangee; i++)
    {
        stringTemp = getNodeByRowColumnIndex( i, 1, gridApp).toString();
        ampApp += parseDouble(stringTemp);
    }

    for(int i =1; i < rangee; i++)
    {
        stringTemp = getNodeByRowColumnIndex(i, 2, gridApp).toString();
        heureApp += parseDouble(stringTemp);
    }

（這只是方法的第一部分，我知道這里缺少“}”）

這是getNodeByRowColumnIndex代碼： 

public Node getNodeByRowColumnIndex( final int row, final int column, GridPane gridPane) {
   Node result = null;
   ObservableList<Node> childrens = gridPane.getChildren();
   for(Node node : childrens) 
   {
        if(gridPane.getRowIndex(node) == row && gridPane.getColumnIndex(node) == column) 
        {
           result = node;
           break;
        }
   }
   return result;
}

我嘗試了此方法，但一直在獲取java.lang.NullPointerException

有誰知道為什么以及如何解決這個問題？

編輯：

根據要求，這里是堆棧跟蹤 

Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
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.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8411)
at javafx.scene.control.Button.fire(Button.java:185)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$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.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$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:380)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:294)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:416)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:415)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
... 48 more
Caused by: java.lang.NullPointerException
at systemesolaire.FXMLDocumentController.getNodeByRowColumnIndex(FXMLDocumentController.java:111)
at systemesolaire.FXMLDocumentController.calculer(FXMLDocumentController.java:81)
... 58 more

這是我初始化孩子的方式（我使用了SceneBuilder，所以這里是FXML文件） 

<content>
        <GridPane fx:id="gridApp" prefHeight="141.0" prefWidth="452.0">
           <columnConstraints>
              <ColumnConstraints hgrow="SOMETIMES" maxWidth="226.0" minWidth="10.0" prefWidth="226.0" />
              <ColumnConstraints hgrow="SOMETIMES" maxWidth="146.0" minWidth="10.0" prefWidth="123.0" />
              <ColumnConstraints hgrow="SOMETIMES" maxWidth="113.0" minWidth="10.0" prefWidth="103.0" />
           </columnConstraints>
           <rowConstraints>
              <RowConstraints minHeight="40.0" prefHeight="40.0" vgrow="NEVER" />
              <RowConstraints minHeight="40.0" prefHeight="40.0" vgrow="NEVER" />
              <RowConstraints minHeight="40.0" prefHeight="40.0" vgrow="NEVER" />
           </rowConstraints>
           <children>
              <Label text="  Nom de l'appareil">
                 <font>
                    <Font name="Anke" size="18.0" />
                 </font>
              </Label>
              <Label text="Ampérage" GridPane.columnIndex="1">
                 <font>
                    <Font name="Anke" size="14.0" />
                 </font>
              </Label>
              <Label text="Heures utilisation" GridPane.columnIndex="2">
                 <font>
                    <Font name="Anke" size="13.0" />
                 </font>
              </Label>
              <TextArea prefHeight="200.0" prefWidth="200.0" promptText="Nom" GridPane.rowIndex="1" />
              <TextArea prefHeight="200.0" prefWidth="200.0" promptText="Amp" GridPane.columnIndex="1" GridPane.rowIndex="1" />
              <TextArea prefHeight="200.0" prefWidth="200.0" promptText="Heure" GridPane.columnIndex="2" GridPane.rowIndex="1" />
              <TextArea prefHeight="200.0" prefWidth="200.0" promptText="Nom" GridPane.rowIndex="2" />
              <TextArea prefHeight="200.0" prefWidth="200.0" promptText="Amp" GridPane.columnIndex="1" GridPane.rowIndex="2" />
              <TextArea prefHeight="200.0" prefWidth="200.0" promptText="Heure" GridPane.columnIndex="2" GridPane.rowIndex="2" />
           </children>
        </GridPane>
     </content>

這是我如何在gridPane中添加一行 

 @FXML
private void ajouteRangee(ActionEvent event) 
{

   TextArea nom =  new TextArea();
   TextArea amp = new TextArea();
   TextArea heure = new TextArea();



   nom.setPromptText("Nom");
   amp.setPromptText("Amp");
   heure.setPromptText("heure");


   gridApp.addRow(rangee, nom, amp, heure);
   gridApp.layout();
   rangee++;

}

1 個解決方案

解決方案1
 1 已采納  2016-09-26 15:30:56

在老師的幫助下，我得到了答案。如果有人遇到同樣的問題，這就是我的解決方法。

NullPointerException用於getColumnIndex，該解決方案繞過了該問題，但是我不知道為什么首先要獲得此異常。

由於行和列的數量是已知的，因此無需在每個節點中搜索正確的行和列。 另外，由於每行的子代數相同，因此有一種邏輯方法可以獲取特定的子代。 這是如何做 ： 

 public TextArea getNodeByRowColumnIndex( final int row, final int column, GridPane gridPane) 
{

   ObservableList<Node> childrens = gridPane.getChildren();
   TextArea result = (TextArea) childrens.get((row*3)+column);

   return result;
}

ObservableList從左到右逐行獲取子對象，因此您可以使用此公式到達列表中的特定對象（（（（rowIndex + 1）*每行對象的數量）+您的對象所在的列）

然后，您可以通過執行以下操作獲取TextArea文本： 

 stringTemp = getNodeByRowColumnIndex( i, 1, gridApp).getText();

暫無
暫無

聲明:本站的技術帖子網頁，遵循CC BY-SA 4.0協議，如果您需要轉載，請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.

相關問題 獲取按鈕在gridPane中並使用javaFx更改其文本 Javafx從gridpane中的文本字段獲取文本 使用GridPane由TextArea覆蓋的JavaFX ListView 從javaFX中的TabPane獲取TextArea 帶換行文字的javafx gridpane布局 GridPane（JavaFX）中的居中按鈕和文本 從JavaFX TextArea獲取Scrollbar / Scrollpane位置 JavaFX-獲取在網格窗格上單擊的位置 JavaFX如何將包裝的文本添加到GridPane Javafx GridPane，如何居中居中？ （文本/標簽）
相關標簽
 
粵ICP備18138465號  © 2020-2024 STACKOOM.COM