在边框中心加载新的fxml [英] Load new fxml in borderpane center
本文介绍了在边框中心加载新的fxml的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
刚开始使用JavaFx（通常也是java的初学者），几天后我一直试图让它工作，但我一直无法解决它。我得到一个空指针异常，我知道这里涉及：
什么是NullPointerException，我该如何解决？
Just started with JavaFx (also a beginner of java generally) and for a few days I've been trying to get this to work but I've been unable to solve it. I'm getting a null pointer exception which I know is covered here: What is a NullPointerException, and how do I fix it?
所以我希望这个问题不会因为重复而被关闭因为我知道什么是npe并且（通常）知道如何解决这个问题。
So I hope this question doesn't get closed as duplicate since I know what npe is and (generally) know how to fix this.
我也知道（大部分时间）如何躲避它们和/或修复它们它发生但在这种情况下我只是不知道如何解决它。
I also know (most of the time) how to dodge them and/or fix them if it occurs but in this case I just don't know how to sort it out.
我还检查了一些关于fxml的其他问题，但仍然无法判断是出。
如何从LeftPane更改CenterPane javaFx borderPane？
在窗格之间切换javaFX中的BorderPane
加载新的fxml相同的场景
I've also checked some other questions regarding fxml but still can't figure is out.
How to change CenterPane from LeftPane in javaFx borderPane?
switching between panes in BorderPane in javaFX
Loading new fxml in the same scene
在我的应用程序中，我想要一个borderpane作为根，在左侧我有三个按钮，取决于什么按钮我按下带有tabpane的新fxml应该加载在borderpane的中心当我按下按钮我得到一个npe，我认为是由于我没有引用右边框但我无法看到我哪里出错了。
In my application I want to have a borderpane as a root and in the left side i have three buttons and depending on what button I press a new fxml with a tabpane should load in the center of the borderpane how ever when i press the button i get a npe which i presume is due to me not referencing the right borderpane but i cant see where i'm going wrong.
我想要做的是当我按下按钮custMenuButton时fxml应加载并设置为中心i在边框窗口。
What I'm trying to do is when i press the button custMenuButton the fxml should load and be set as center in the borderpane.
主要类
import java.io.IOException;
import javafx.application.Application;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
public class Main extends Application {
@FXML
private BorderPane root;
Stage window;
@Override
public void start(Stage primaryStage) throws IOException {
window = primaryStage;
FXMLLoader loader = new FXMLLoader(Main.class.getResource("MainWindowView.fxml"));
this.root = loader.load();
MainWindowController mwc = new MainWindowController();
mwc.setMain(this);
Scene scene = new Scene(root);
window.setTitle("JavaFX");
window.setScene(scene);
window.show();
}
public static void main(String[] args) {
launch(args);
}
public BorderPane getBorderPane() {
return root;
}
}
主窗口控制器
import java.io.IOException;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.control.Button;
import javafx.scene.control.TabPane;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.VBox;
public class MainWindowController {
private Main main;
@FXML private BorderPane root;
@FXML private VBox sideBox;
@FXML private Button custMenuButton;
@FXML private Button accMenuButton;
@FXML private Button transMenuButton;
public void setMain(Main main) {
this.main = main;
}
public void handleCustMenuButton() throws IOException {
FXMLLoader loader = new FXMLLoader(getClass().getResource("CustomerView.fxml"));
TabPane pane = (TabPane) loader.load();
CustomerViewController cvc = loader.getController();
cvc.setMain(main);
main.getBorderPane().setCenter(pane);
}
}
客户视图控制器
import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
public class CustomerViewController implements Initializable {
Main main;
@FXML private TabPane custTabPane;
@FXML private Tab createTab;
@FXML private Tab listAllTab;
@FXML private Tab deleteTab;
public void setMain(Main main){
this.main = main;
}
@Override
public void initialize(URL url, ResourceBundle rb) {
// TODO
}
}
Mainwindowview
Mainwindowview
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Menu?>
<?import javafx.scene.control.MenuBar?>
<?import javafx.scene.control.MenuItem?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.VBox?>
<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="600.0" prefWidth="800.0" xmlns="http://javafx.com/javafx/8.0.141" xmlns:fx="http://javafx.com/fxml/1" fx:controller="firstfx.MainWindowController">
<top>
<MenuBar BorderPane.alignment="CENTER">
<menus>
<Menu mnemonicParsing="false" text="File">
<items>
<MenuItem mnemonicParsing="false" text="Close" />
</items>
</Menu>
<Menu mnemonicParsing="false" text="Help">
<items>
<MenuItem mnemonicParsing="false" text="About" />
</items>
</Menu>
</menus>
</MenuBar>
</top>
<left>
<VBox fx:id="sideBox" prefHeight="200.0" prefWidth="150.0" spacing="2.0" BorderPane.alignment="CENTER">
<children>
<Button fx:id="custMenuButton" mnemonicParsing="false" onAction="#handleCustMenuButton" prefHeight="50.0" prefWidth="130.0" text="Kundmeny" />
<Button fx:id="accMenuButton" mnemonicParsing="false" prefHeight="50.0" prefWidth="130.0" text="Kontomeny" />
<Button fx:id="transMenuButton" mnemonicParsing="false" prefHeight="50.0" prefWidth="130.0" text="Transaktioner" />
</children>
<padding>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</padding>
</VBox>
</left>
</BorderPane>
客户视图fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Tab?>
<?import javafx.scene.control.TabPane?>
<?import javafx.scene.layout.AnchorPane?>
<TabPane fx:id="custTabPane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" tabClosingPolicy="UNAVAILABLE" xmlns="http://javafx.com/javafx/8.0.141" xmlns:fx="http://javafx.com/fxml/1" fx:controller="firstfx.CustomerViewController">
<tabs>
<Tab fx:id="createTab" text="Skapa kund">
<content>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0" />
</content>
</Tab>
<Tab fx:id="listAllTab" text="Lista alla kunder">
<content>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0" />
</content>
</Tab>
<Tab fx:id="deleteTab" text="Radera kund">
<content>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0" />
</content>
</Tab>
</tabs>
</TabPane>
Stacktrace
Stacktrace
Executing /home/garnbutik/NetBeansProjects/FirstFX/dist/run1223809748/FirstFX.jar using platform /home/garnbutik/jdk1.8.0_151/jre/bin/java
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:8413)
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$MouseEventNotification.run(GlassViewEventHandler.java:381)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$353(GlassViewEventHandler.java:417)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
at com.sun.glass.ui.gtk.GtkApplication.lambda$null$48(GtkApplication.java:139)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771)
... 48 more
Caused by: java.lang.NullPointerException
at firstfx.MainWindowController.handleCustMenuButton(MainWindowController.java:31)
... 58 more
BUILD STOPPED (total time: 4 minutes 14 seconds)
推荐答案
你没有在cr的控制器上调用 setMain（...）在加载 MainWindowView.fxml 时加载。因此，当您尝试执行 MainWindowController 时
You don't call setMain(...) on the controller that is created when you load MainWindowView.fxml. Consequently in MainWindowController when you try to do
main.getBorderPane()...
你得到一个空指针异常。
you get a null pointer exception.
在 start（）方法中，您需要以稍后在 handleCustMenuButton（...）中执行的方式获取控制器，即
In your start() method, you need to get the controller in the same way you do later in handleCustMenuButton(...), i.e.
FXMLLoader loader = new FXMLLoader(Main.class.getResource("MainWindowView.fxml"));
this.root = loader.load();
// MainWindowController mwc = new MainWindowController();
MainWindowController mwc = loader.getController();
mwc.setMain(this);
这篇关于在边框中心加载新的fxml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！
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