本文介绍了如何在 JavaFX 中切换场景的处理方法，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
我查看了很多页面，试图找出如何切换场景，但都没有成功.
I have looked on many pages to try and find out how to switch scenes but I have been unsuccessful.
我有一个计算器，我的目标是选择一个菜单选项来更改计算器(即:基本和科学).现在我只是在测试，所以这是我迄今为止与这个问题相关的代码(我正在使用 Scene Builder):
I have a calculator and my goal is to select a menu option to change Calculators(ie: basic and scientific). Right now I am just testing so here is my code relevant to this question thus far (I am using Scene Builder):
@FXML private MenuItem basic;
@FXML private MenuItem testSwitch;
public static void main(String[] args)
{
Application.launch( args );
}
@Override
public void start(Stage primaryStage) throws Exception
{
Parent pane = FXMLLoader.load(
getClass().getResource( "calculator.fxml" ) );
Scene scene = new Scene( pane );
primaryStage.setScene(scene);
primaryStage.setTitle( "Calculator" );
primaryStage.show();
}
@FXML
public void handleMenuOption(ActionEvent e)
{
if(e.getSource()==basic)
{
changeScene("calculator.fxml");
}
else if(e.getSource()==testSwitch)
{
changeScene("TestSwitch.fxml");
}
}
public void changeScene(String fxml)
{
//this prints out
System.out.println(fxml);
}
编辑我已经尝试了很多东西.不管怎样，我总是得到这个 NullPointerException.我有一种感觉，这可能与在场景构建器中设置某些内容有关，但我一直找不到答案
EDITI've tried quite a few things already. No matter what, I always get this NullPointerException. I have a feeling it may have to do with setting something in scene builder but I just have not been able to find an answer
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(Unknown Source)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at javafx.event.Event.fireEvent(Unknown Source)
at javafx.scene.control.MenuItem.fire(Unknown Source)
at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer.doSelect(Unknown Source)
at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer.lambda$createChildren$343(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at javafx.event.Event.fireEvent(Unknown Source)
at javafx.scene.Scene$MouseHandler.process(Unknown Source)
at javafx.scene.Scene$MouseHandler.access$1500(Unknown Source)
at javafx.scene.Scene.impl_processMouseEvent(Unknown Source)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(Unknown Source)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
at com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
at com.sun.glass.ui.View.notifyMouse(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.reflect.misc.Trampoline.invoke(Unknown Source)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.reflect.misc.MethodUtil.invoke(Unknown Source)
... 44 more
Caused by: java.lang.NullPointerException
at CalculatorMain.changeScene(CalculatorMain.java:75)
at CalculatorMain.handleMenuOption(CalculatorMain.java:64)
... 53 more
at CalculatorMain.changeScene(CalculatorMain.java:75)
This is at:stage . getScene() . setRoot(pane);
at CalculatorMain.handleMenuOption(CalculatorMain.java:64)
This is at:changeScene ("TestSwitch.fxml");
工作代码:
我尝试使用以下建议并使用此代码使其工作:
I played around using suggestions below and used this code to make it work:
private Stage stage;
public static void main(String[] args)
{
Application.launch( args );
}
@Override
public void start(Stage primaryStage) throws Exception
{
this.stage = primaryStage;
FXMLLoader loader = new FXMLLoader(getClass()
.getResource("calculator.fxml"));
Parent root = (Parent)loader.load();
BasicCalculatorView controller = (BasicCalculatorView)loader.getController();
controller.setModel(new BasicCalculatorModelTest(controller));
controller.setLogic(this);
primaryStage.setTitle("Calculator");
primaryStage.setScene(new Scene(root));
primaryStage.show();
}
public void switchScene(String fxmlFile)
{
FXMLLoader loader = new FXMLLoader(getClass()
.getResource(fxmlFile));
Parent root;
try
{
root = (Parent)loader.load();
if(fxmlFile.equals("calculator.fxml"))
{
BasicCalculatorView controller = (BasicCalculatorView)loader.getController();
controller.setModel(new BasicCalculatorModelTest(controller));
controller.setLogic(this);
}
else if(fxmlFile.equals("TestSwitch.fxml"))
{
TestSwitch controller = (TestSwitch)loader.getController();
controller.setLogic(this);
}
this.stage.setScene(new Scene(root));
}
catch (IOException e)
{
e.printStackTrace();
}
}
推荐答案
我编写了这个控制器来跟踪不同的场景图.
I wrote this controller to keep track of the different scenegraphes.
public class ScreenController {
private HashMap<String, Pane> screenMap = new HashMap<>();
private Scene main;
public ScreenController(Scene main) {
this.main = main;
}
protected void addScreen(String name, Pane pane){
screenMap.put(name, pane);
}
protected void removeScreen(String name){
screenMap.remove(name);
}
protected void activate(String name){
main.setRoot( screenMap.get(name) );
}
}
所以我可以写:
ScreenController screenController = new ScreenController(scene);
screenController.add("calculator", FXMLLoader.load(getClass().getResource( "calculator.fxml" )));
screenController.add("testSwitch", FXMLLoader.load(getClass().getResource( "TestSwitch.fxml" )));
screenController.activate("calculator");
这是全屏应用程序的一种解决方法，每次舞台切换场景时都会显示 MacOS 全屏转换.
This was a workaround for a fullscreen application, where the MacOS fullscreen transition was shown every time a stage switches its scene.
这篇关于如何在 JavaFX 中切换场景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！