我想通过单击按钮将FXML加载到我的BorderPane中。
问题是，我单击按钮[语言]时会收到以下错误：
由以下原因引起：java.lang.NullPointerException 在control.options.options.onLanguageClick（options.java:83））
问题是我（可能发生错误？）无法访问控制器中的内容窗格。
view.options.Options.java
package view.options;
import constants.FileConstants;
import javafx.application.*;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
import javafx.scene.text.Font;
import javafx.stage.Stage;
public class Options extends Application {
@Override
public void init() throws Exception {
super.init();
Font.loadFont(getClass().getResourceAsStream(FileConstants.OPTIONS_PATH + "/resources/options/Seattle_Avenue.ttf"), 14);
}
public static void main(String[] args) {
Application.launch(args);
System.out.println("exited");
}
@Override
public void start(Stage primaryStage) throws Exception {
BorderPane mainBorderPane = FXMLLoader.load(Options.class.getResource("main.fxml"));
primaryStage.setScene(new Scene(mainBorderPane));
primaryStage.show();
}
}
view.options.main.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.Pane?>
<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="720.0" prefWidth="1280.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="control.options.options">
<top>
<fx:include source="title.fxml"/>
</top>
<bottom>
<fx:include source="bottom.fxml"/>
</bottom>
<left>
<fx:include source="left.fxml"/>
</left>
<center>
<!--
<fx:include source="resolutionSettings.fxml"/>
-->
<Pane fx:id="content"/>
</center>
</BorderPane>
view.options.languageSettings.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.RadioButton?>
<?import javafx.scene.control.ToggleGroup?>
<?import javafx.scene.layout.Pane?>
<Pane xmlns:fx="http://javafx.com/fxml/1" fx:id="content" xmlns="http://javafx.com/javafx/8.0.171"
fx:controller="control.options.options">
<RadioButton fx:id="languageGerman" layoutX="274.0" layoutY="114.0" mnemonicParsing="false" text="Deutsch">
<toggleGroup>
<ToggleGroup fx:id="language" />
</toggleGroup></RadioButton>
<RadioButton fx:id="languageEnglish" layoutX="274.0" layoutY="199.0" mnemonicParsing="false" text="English" toggleGroup="$language" />
<Button layoutX="758.0" layoutY="406.0" mnemonicParsing="false" onAction="#onLanguageSaveClick" text="Save" />
</Pane>
control.options.options.java
package control.options;
import java.io.IOException;
import java.net.URL;
import java.util.ResourceBundle;
import constants.FileConstants;
import javafx.application.Platform;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.control.Label;
import javafx.scene.control.RadioButton;
import javafx.scene.control.Slider;
import javafx.scene.control.ToggleGroup;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Pane;
import view.options.Options;
import javax.swing.event.TreeModelEvent;
public class options {
@FXML
private ResourceBundle resources;
@FXML
private URL location;
@FXML
private Label label_general;
@FXML
private Label label_effects;
@FXML
private Label label_music;
@FXML
private Pane content;
@FXML
private Slider slider_general;
@FXML
private Slider slider_effects;
@FXML
private Slider slider_music;
@FXML
private ToggleGroup language;
@FXML
private RadioButton languageGerman;
@FXML
private RadioButton languageEnglish;
@FXML
void onEffectsChanged(MouseEvent event) {
int sliderValue = (int) slider_effects.getValue();
System.out.println(sliderValue + " ");
label_effects.setText("general (" + slider_effects.getValue()+"%)");
}
@FXML
void onExitClick(ActionEvent event) {
Platform.exit();
}
@FXML
void onGeneralChanged(MouseEvent event) {
int sliderValue = (int) slider_general.getValue();
System.out.println(sliderValue + " ");
label_general.setText("general (" + slider_general.getValue()+"%)");
}
@FXML
void onGraphicsClick(ActionEvent event) {
}
@FXML
void onLanguageClick(ActionEvent event) throws IOException {
System.out.println("click! taskBarButton2");
Parent language = FXMLLoader.load(getClass().getResource("/view/options/languageSettings.fxml"));
content.getChildren().clear();
content.getChildren().add(language);
}
@FXML
void onLanguageSaveClick(ActionEvent event) {
RadioButton selectedRadioButton = (RadioButton) language.getSelectedToggle();
String toogleGroupValue = selectedRadioButton.getText();
System.out.println(toogleGroupValue);
}
@FXML
void onMusicChanged(MouseEvent event) {
int sliderValue = (int) slider_music.getValue();
System.out.println(sliderValue + " ");
label_music.setText("general (" + slider_music.getValue()+"%)");
}
@FXML
void onResolutionSaveClick(ActionEvent event) {
}
@FXML
void onSoundClick(ActionEvent event) {
}
@FXML
void initialize() {
}
}
这是错误日志：
click! taskBarButton2
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$2(GlassViewEventHandler.java:417)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$3(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
... 48 more
Caused by: java.lang.NullPointerException
at control.options.options.onLanguageClick(options.java:83)
... 58 more
exited
Process finished with exit code 0
options.java:83是content.getChildren().clear();
因此，FXML的加载不是问题。孩子们的清理是。