Question

我试图在不同的场景之间切换/尽可能地加载不同的fxml文件。我已经对它进行了研究，以达到永恒的感觉，并且我知道有几种解决方案，但是它们似乎都以某种方式重复了这段代码：

Parent root = FXMLLoader.load(getClass().getResource("main.fxml"));
primaryStage.setTitle("Login");
primaryStage.setScene(new Scene(root));
primaryStage.show();

所以我认为可以实现MainController，实现某种switch()方法，并将MainController注入每个子Controller中。

好吧，好像我将自己重新陷入困境，目前陷入困境。可以这么说，我把自己编码成一条沟。

所以我有几个问题：

这种方法值得追求吗？真的有用吗？
如果是这样，我需要更改什么？我的错误在哪里？
您如何更大程度地应对这一问题？当然必须有更好的方法吗？

代码和错误代码发布在下面。我知道很多代码，但是尽我所能简化了代码。任何帮助和/或反馈都非常有用。

代码

主要

package test;

import java.io.IOException;
import javafx.application.Application;
import javafx.stage.Stage;

public class Main extends Application {

  public static void main(String[] args) {
    launch(args);
  }

  @Override
  public void start(Stage primaryStage) throws IOException {
    MainController mainController = new MainController(primaryStage);
    mainController.switchScreenState(ScreenState.GOTO1);
  }
}

main.fxml

<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.layout.AnchorPane?>
<AnchorPane prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.172-ea"
  xmlns:fx="http://javafx.com/fxml/1" fx:controller="test.MainController">
  <fx:include source="one.fxml"/>
</AnchorPane>

MainController

package test;

import java.io.IOException;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class MainController {

  @FXML private TwoController twoController;
  @FXML private OneController oneController;

  private Stage mainWindow;

  MainController(Stage mainWindow) {
    this.mainWindow = mainWindow;
  }

  @FXML
  private void initialize() {
    twoController.injectMainController(this);
  }

  public void switchScreenState(ScreenState state) throws IOException {
    switch (state) {
      case GOTO1:
        mainWindow.setScene(loadFXML("test/one.fxml"));
        break;
      case GOTO2:
        mainWindow.setScene(loadFXML("test/two.fxml"));
        break;
      default:
        //throw IllegaleStateexeption?
    }
    mainWindow.show();
  }

  private Scene loadFXML(String fxml) throws IOException {
    return new Scene(FXMLLoader.load(getClass().getResource(fxml)));
  }
}

one.fxml

<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.AnchorPane?>
<AnchorPane prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.172-ea"
  xmlns:fx="http://javafx.com/fxml/1" fx:controller="test.OneController">

  <Button layoutX="271.0" layoutY="187.0" mnemonicParsing="false" text="Switch to Two"
    onAction="#switchToTwo"/>
</AnchorPane>

OneController

package test;

import java.io.IOException;
import javafx.event.ActionEvent;

public class OneController {

  private MainController mainController;

  public void switchToTwo(ActionEvent event) throws IOException {
    mainController.switchScreenState(ScreenState.GOTO2);
  }

  public void injectMainController(MainController mainController) {
    this.mainController = mainController;
  }
}

ScreenState

package test;

public enum ScreenState {
  GOTO1,GOTO2

}

two.fxml和TwoController几乎相同。

当前我收到此错误：

/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/bin/java "-javaagent:/Applications/IntelliJ IDEA.app/Contents/lib/idea_rt.jar=54051:/Applications/IntelliJ IDEA.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath /Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/deploy.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/cldrdata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/dnsns.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/jaccess.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/jfxrt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/localedata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/nashorn.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/sunec.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/ext/zipfs.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/javaws.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/jfxswt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/management-agent.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/plugin.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/lib/ant-javafx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/lib/dt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/lib/javafx-mx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/lib/jconsole.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/lib/packager.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/lib/sa-jdi.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home/lib/tools.jar:/Users/maltewilhelm/Documents/LMU/18-19_WS/18W_informatik/SEP_Java/tasks/ex04-group-task/out/production/ex04-group-task test.Main
Exception in Application start method
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 com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
    at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
    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.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$154(LauncherImpl.java:182)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException: Location is required.
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3207)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
    at test.MainController.loadFXML(MainController.java:40)
    at test.MainController.switchScreenState(MainController.java:28)
    at test.Main.start(Main.java:17)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$161(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$174(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl.lambda$null$172(PlatformImpl.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$173(PlatformImpl.java:294)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
Exception running application test.Main

优雅地切换场景

0 个答案: