ImageView setImage RuntimeException NullPointerException-Java 学习之路

有2个 *.fxml file ，每个都连接到 *.java 文件 . 在 one.fxml 中有 ImageView FX: ID = "image" 如何在 ImageView 图像文件 one.fxml 中安装 TwoController.java 的图像 .

它我的代码TwoController.java：

OneController oneJavaFile;
Image img = new Image(getClass().getResource("logo.png").toExternalForm());
ImageView image = new ImageView(img);
oneJavaFile.anchorPane.getChildren().add(image); // 46 line

代码在one.fxml中

@FXML
public ImageView image;

@FXML
public AnchrorPane anchorPane

为什么我得到的是例外：

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.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.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$MouseEventNotification.run(GlassViewEventHandler.java:380)
 at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:294)
 at java.security.AccessController.doPrivileged(Native Method)
 at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:416)
 at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
 at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:415)
 at com.sun.glass.ui.View.handleMouseEvent(View.java:555) at com.sun.glass.ui.View.notifyMouse(View.java:937)
 at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
 at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
 at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:498)
 at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
 at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:498)
 at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
 at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771)
... 52 more
Caused by: java.lang.NullPointerException
 at sample.MenuController.OnClickScaner(MenuController.java:46)
... 62 more

1 回答

可能是不完美的解决方案，但它是一个有效的

OneController.java

@FXML
public static ImageView image;

@FXML
public AnchorPane anchorPane;

@FXML
public void initialize(URL url, ResourceBundle br) {
        click();
}

void click(){
TwoController contr = new TwoController();
image = new Image();
if(image != null){
Image i = null;
Image im = contr.setImage(i);
image.setImage(contr.setImage(im));
anchorPane.getChildren().add(image);
  }
}

TwoController.java

....
public Image setImage(Image img){
Image img = null;
    i = img;
    i = new Image(String.valueOf(getClass().getResource("logo.png")));
return img;
}

回复于 2024-05-02T10:21:44+08:00

ImageView setImage RuntimeException NullPointerException

1 回答

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