Javafx-将FXML组件加载到选项卡上时FXML加载异常

Question

我想拥有一个带有标签的页面，在每个选项卡中，我将调用另一个FXML组件。我已经尝试了很多答案，它们都不对我有用。我的TABPANE为home.fxml的主页以及我要调用的选项卡之一，我要调用view.fxml。现在，我正在尝试这种方法：

home.fxml页面：

<VBox xmlns="http://javafx.com/javafx/8"
  xmlns:fx="http://javafx.com/fxml/1"
  prefHeight="${screen.visualBounds.height}"
  fx:controller="pkg.magazineservice.home_controller"
  fx:id="wrapper">

<fx:define>
    <Screen fx:factory="getPrimary" fx:id="screen" />
</fx:define>

<VBox style="-fx-background-color: #003d80" alignment="CENTER" prefHeight="${wrapper.height * 0.10}" >
    <Label BorderPane.alignment="CENTER" style="-fx-text-fill: white" text="Magazine Service" >
        <font>
            <Font size="32" />
        </font>
    </Label>
</VBox>

<TabPane style="-fx-close-tab-animation: none" fx:id="contentWrapper" prefHeight="${wrapper.height * 0.9}" prefWidth="${screen.visualBounds.width}">
    <Tab fx:id="View" text="View">
        <VBox>
            <!--<fx:include source="view.fxml" />-->
        </VBox>
    </Tab>
    <Tab fx:id="Create" text="Create">
        <VBox>
            <!--<fx:include source="view.fxml" />-->
        </VBox>
    </Tab>
    <Tab fx:id="Edit" text="Edit">
        <VBox>
            <!--<fx:include source="view.fxml" />-->
        </VBox>
    </Tab>
</TabPane>

On it's controller, I'm trying to initialize a page:

home_controller.java

 @Override
public void initialize(URL location, ResourceBundle resources)
{
    try
    {
        Tab tab = new Tab();
        View.setContent((Node) FXMLLoader.load(this.getClass().getResource("view.fxml")));
    }
    catch(IOException iex)
    {
        System.out.println(iex.getCause().toString());
        System.out.println("File not found");
    }
} 

但是，它一直在扔JavanullPoInterException。

这是view.fxml：

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<?import javafx.stage.Screen?>

<VBox xmlns="http://javafx.com/javafx/8"
     xmlns:fx="http://javafx.com/fxml/1"
     fx:id="View"
     alignment="CENTER"
     prefHeight="${screen.height * 0.9}"
     prefWidth="${screen.visualBounds.width}"
     fx:controller="pkg.magazineservice.view_controller"
     >

<fx:define>
    <Screen fx:factory="getPrimary" fx:id="screen" />
</fx:define>

<VBox fx:id="listsWrapper" alignment="CENTER" prefHeight="${View.height}" prefWidth="${View.width * 0.50}">
    <VBox>

    </VBox>

    <Separator orientation="HORIZONTAL" prefWidth="${listsWrapper.width}" style="-fx-background-color: black" />

    <VBox>

    </VBox>

    <Separator orientation="VERTICAL" prefHeight="${View.height}" style="-fx-background-color: black" />

    <VBox fx:id="detailsWrapper" alignment="CENTER" prefHeight="${View.height}" prefWidth="${View.width * 0.50}">

    </VBox>
</VBox>

我已经尝试使用fx：root，但它一直抱怨root未被设置，我不知道如何在家中实现root控制器。任何帮助和建议都很棒！

编辑： StackTrace：

javafx.fxml.LoadException:
/MagazineService/target/classes/pkg/magazineservice/view.fxml:40

at javafx.fxml/javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2625)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2603)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2466)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3237)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3194)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3163)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3136)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3113)
at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:3106)
at com.magazineservice.magazineservice/pkg.magazineservice.home_controller.initialize(home_controller.java:40)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2573)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2466)
at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:2435)
at com.magazineservice.magazineservice/pkg.magazineservice.HelloApplication.start(HelloApplication.java:25)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:846)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:455)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:428)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:427)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.NullPointerException
at javafx.fxml/com.sun.javafx.fxml.expression.Expression.lambda$multiply$2(Expression.java:928)
at javafx.fxml/com.sun.javafx.fxml.expression.BinaryExpression.evaluate(BinaryExpression.java:55)
at javafx.fxml/com.sun.javafx.fxml.expression.ExpressionValue.getValue(ExpressionValue.java:192)
at javafx.base/com.sun.javafx.binding.ExpressionHelper.addListener(ExpressionHelper.java:53)
at javafx.base/javafx.beans.value.ObservableValueBase.addListener(ObservableValueBase.java:55)
at javafx.fxml/com.sun.javafx.fxml.expression.ExpressionValue.addListener(ExpressionValue.java:201)
at javafx.base/javafx.beans.binding.DoubleBinding.bind(DoubleBinding.java:152)
at javafx.base/javafx.beans.property.DoublePropertyBase$ValueWrapper.<init>(DoublePropertyBase.java:277)
at javafx.base/javafx.beans.property.DoublePropertyBase$2.<init>(DoublePropertyBase.java:182)
at javafx.base/javafx.beans.property.DoublePropertyBase.bind(DoublePropertyBase.java:182)
at javafx.graphics/javafx.css.StyleableDoubleProperty.bind(StyleableDoubleProperty.java:75)
at javafx.fxml/javafx.fxml.FXMLLoader$Element.processPropertyAttribute(FXMLLoader.java:326)
at javafx.fxml/javafx.fxml.FXMLLoader$Element.processInstancePropertyAttributes(FXMLLoader.java:242)
at javafx.fxml/javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:775)
at javafx.fxml/javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2838)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2557)
... 21 more

Answer 1

多亏了@james_d的评论，他指出prefwidth和prefheight是问题所在。只需从view.fxml删除这些行就解决了我的问题。

解决方案：

<VBox xmlns="http://javafx.com/javafx/8"
 xmlns:fx="http://javafx.com/fxml/1"
 fx:id="View"
 alignment="CENTER"
 fx:controller="pkg.magazineservice.view_controller"
 >
<!-- NO WIDTH AND HEIGHT-->