Javafx setImage für ImageView von einem anderen FXML-Controller

Question

Ich habe eine Klasse namens "AdjustmentBar", die eine ImageView, eine Menüleiste und einige Bildbearbeitungsfunktionen (eine FXML-Datei und ein Controller) enthält. AdjustmentBar wird in eine andere Klasse namens "ExaminationDisplayer" (auch eine FXML-Datei und ein Controller) geladen. ExaminationDisplayer lädt einige Bilder aus einer Online-MySQL-Datenbank, und ich möchte, dass jedes dieser Bilder in einem separaten Bild angezeigt wird.

Ich konnte die AdjustmentBar in den ExaminationDisplayer laden, aber ich kann nicht herausfinden, wie ImageImage() des imageView gesetzt wird, das in AdjustmentBar enthalten ist. Ich kann ein Bild von der Datenbank in einer Bildansicht anzeigen, die ich speziell im ExaminationDisplayer mache, und ich kann ein Bild in der AdjustmentBar-Ansicht anzeigen, wenn ich das separat ausführe. Ich kann die geladene Justierungsleiste nicht aufrufen, um das Bild im ExaminationDisplayer anzuzeigen.

Wenn ich es laufen bekomme ich einen Fehler Nullpointer für diese Codezeile: imgView.setImage (Bild), die in dem ExaminationDisplayerController ist:

public class ExaminationDisplayerController extends AdjustmentBarController { 
    @FXML 
    private void handlebtnFraminghamAction(ActionEvent event) throws IOException {showCardiacConditionEstimator(); } 
    @FXML 
    private AnchorPane anchorPane; 
    @FXML 
    private LineChart<Number, Number> lcChart; 
    @FXML 
    private NumberAxis xAxis; // x-Axis is defined 
    @FXML 
    private NumberAxis yAxis; //y-Axis is defined 

    public void initialize() throws ClassNotFoundException, SQLException, IOException { // Loading methods in ExaminationDisplayerController 
     SPECTLoad(); 
    } 

    public void showCardiacConditionEstimator() throws IOException { // Method for displaying CardiacConditionEstimator 
     Parent parent = FXMLLoader.load(getClass().getResource("/fxml/CardiacConditionEstimator.fxml")); //Reference to the fxml file 
     Stage stage = new Stage(); // creating a new stage 
     Scene scene = new Scene(parent); // creating a new scene for the file to be shown onto 
     stage.setScene(scene); // sets the scene on the stage 
     stage.show(); // Displaying the stage 
     stage.setMaximized(false); // maximizing the stage 
    } 

    public void SPECTLoad() throws SQLException, ClassNotFoundException { 
     DBConnection dbConn = new DBConnection(); 
     Connection conn = dbConn.connect(); 
     PreparedStatement pstmt = null; 

     try { 

      for (int numberOfExaminations = 0; numberOfExaminations < 3; numberOfExaminations++) { 

       String[] ID = {"1111", "1112", "1113"}; 
       List<String> chosenExaminations = Arrays.asList(ID); 
       String SQL = "SELECT `IMAGE` FROM `SPECT` WHERE `ID` = ?;"; 
       pstmt = conn.prepareStatement(SQL); 

       pstmt.setString(1, chosenExaminations.get(numberOfExaminations)); 

       ResultSet rs = pstmt.executeQuery(); 

       while (rs.next()) { 
        InputStream is = rs.getBinaryStream("IMAGE"); 
        OutputStream os = new FileOutputStream(new File("SPECT_IMAGE.jpg")); 

        byte[] content = new byte[1024]; 
        int size = 0; 
        while ((size = is.read(content)) != -1) { // Når inputstream er real passer den et -1 værdi og så stoppes loopet 
         os.write(content, 0, size); 
        } 
        os.close(); 
        is.close(); 

        Image image = new Image(new File("SPECT_IMAGE.jpg").toURI().toString(), 200, 200, true, true); 

        anchorPane.getChildren().add(FXMLLoader.load(getClass().getResource("/fxml/AdjustmentBar.fxml"))); 
        imgView.setImage(image); 
       } 
      } 

//} 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

Hier ist der Code für AdjustmentBarController:

public class AdjustmentBarController { 

    @FXML 
    private AnchorPane AnchorPane; 
    @FXML 
    private ScrollPane ScrollPane; 
    @FXML 
    public ImageView imgView; 
    @FXML 
    private Slider contrastAdjuster; 
    @FXML 
    private ToggleButton btnMeasure; 
    @FXML 
    private Pane imgContainer; 
    @FXML 
    private Label txtLabel; 

    @FXML 
    private void btnZoomInAction(ActionEvent event) {...} 

    @FXML 
    private void btnZoomOutAction(ActionEvent event) {...} 

    @FXML 
    private void btnRotateRightAction(ActionEvent event) {...} 

    @FXML 
    private void btnRotateLeftAction(ActionEvent event) {...} 

    /** 
    * Initializes the controller class. 
    * 
    * @param url 
    * @param rb 
    */ 
    public void initialize(URL url, ResourceBundle rb 
    ) { 
     contrastAdjuster.valueProperty().addListener((observable, oldValue, newValue) -> { 
      double value = contrastAdjuster.getValue(); 
      ColorAdjust colorAdjust = new ColorAdjust(); 
      colorAdjust.setContrast(value); 
      imgView.setEffect(colorAdjust); 
     }); 
    } 
} 

ich bin mir nicht sicher, ob die FXML Datei für AdjustmentBar relevant ist, aber hier geht:

<?xml version="1.0" encoding="UTF-8"?> 

<?import javafx.geometry.Insets?> 
<?import javafx.scene.control.Button?> 
<?import javafx.scene.control.Label?> 
<?import javafx.scene.control.ScrollPane?> 
<?import javafx.scene.control.Slider?> 
<?import javafx.scene.control.ToggleButton?> 
<?import javafx.scene.image.Image?> 
<?import javafx.scene.image.ImageView?> 
<?import javafx.scene.layout.AnchorPane?> 
<?import javafx.scene.layout.BorderPane?> 
<?import javafx.scene.layout.HBox?> 
<?import javafx.scene.layout.Pane?> 

<AnchorPane id="AnchorPane" prefHeight="435.0" prefWidth="435.0" xmlns="http://javafx.com/javafx/8.0.111" xmlns:fx="http://javafx.com/fxml/1" fx:controller="Multimodality.controller.AdjustmentBarController"> 
    <children> 
     <BorderPane prefHeight="435.0" prefWidth="435.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0"> 
     <center> 
      <ScrollPane fx:id="ScrollPane" pannable="true" prefHeight="435.0" prefWidth="435.0" BorderPane.alignment="CENTER"> 
       <content> 
        <Pane fx:id="imgContainer"> 
        <children> 
          <ImageView fx:id="imgView" fitHeight="400.0" fitWidth="400.0" nodeOrientation="INHERIT" pickOnBounds="true" preserveRatio="true" /> 
         <Label fx:id="txtLabel" alignment="TOP_LEFT" layoutX="336.0" layoutY="-1.0" prefHeight="134.0" prefWidth="75.0" wrapText="true" /> 
        </children> 
        </Pane> 
       </content> 
      </ScrollPane> 
     </center> 
     <bottom> 
      <HBox alignment="CENTER" prefHeight="35.0" prefWidth="435.0" spacing="8.0" BorderPane.alignment="CENTER"> 
       <children> 
         <Button fx:id="btnZoomOut" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" onAction="#btnZoomOutAction" prefHeight="25.0" prefWidth="25.0"> 
          <graphic> 
           <ImageView fitHeight="20.0" fitWidth="20.0" preserveRatio="true"> 
            <image> 
             <Image url="/img/icon_zoomout.png" /> 
            </image> 
           </ImageView> 
          </graphic> 
         </Button> 
         <Button fx:id="btnZoom100" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" onAction="#btnZoom100Action" prefHeight="25.0" prefWidth="25.0"> 
          <graphic> 
           <ImageView fitHeight="20.0" fitWidth="20.0" preserveRatio="true"> 
            <image> 
             <Image url="/img/icon_fit.png" /> 
            </image> 
           </ImageView> 
          </graphic> 
         </Button> 
         <Button fx:id="btnZoomIn" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" onAction="#btnZoomInAction" prefHeight="25.0" prefWidth="25.0"> 
          <graphic> 
           <ImageView fitHeight="20.0" fitWidth="20.0" preserveRatio="true"> 
            <image> 
             <Image url="/img/icon_zoomin.png" /> 
            </image> 
           </ImageView> 
          </graphic> 
         </Button> 
         <Button fx:id="btnRotateRight" contentDisplay="CENTER" graphicTextGap="0.0" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" onAction="#btnRotateRightAction" prefHeight="25.0" prefWidth="25.0"> 
          <graphic> 
           <ImageView fitHeight="20.0" fitWidth="20.0" preserveRatio="true"> 
            <image> 
             <Image url="/img/shape_rotate_clockwise.png" /> 
            </image> 
           </ImageView> 
          </graphic> 
         </Button>  
         <Button fx:id="btnRotateLeft" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" onAction="#btnRotateLeftAction" prefHeight="25.0" prefWidth="25.0"> 
          <graphic> 
           <ImageView fitHeight="20.0" fitWidth="20.0" preserveRatio="true"> 
            <image> 
             <Image url="/img/shape_rotate_anticlockwise.png" /> 
            </image> 
           </ImageView> 
          </graphic> 
         </Button> 
        <ToggleButton fx:id="btnMeasure" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" mnemonicParsing="false" onAction="#btnMeasureAction" prefHeight="25.0" prefWidth="25.0"> 
        <graphic> 
         <ImageView fitHeight="20.0" fitWidth="20.0" preserveRatio="true"> 
          <image> 
           <Image url="/img/ruler.png" /> 
          </image> 
         </ImageView> 
        </graphic> 
        </ToggleButton> 
        <ImageView fitHeight="20.0" fitWidth="20.0" preserveRatio="true"> 
        <image> 
         <Image url="/img/contrast.png" /> 
        </image> 
        <HBox.margin> 
         <Insets left="8.0" right="-2.0" /> 
        </HBox.margin> 
        </ImageView> 
         <Slider fx:id="contrastAdjuster" blockIncrement="0.1" majorTickUnit="0.5" max="1.0" min="-1.0" minorTickCount="4" prefHeight="24.0" prefWidth="128.0" showTickMarks="true" /> 
       </children> 
       <BorderPane.margin> 
        <Insets /> 
       </BorderPane.margin> 
      </HBox> 
     </bottom> 
     </BorderPane> 
    </children> 
</AnchorPane> 

Last but not least, hier ist die Nullpointer ich, wenn ich den Code ausführen:

java.lang.NullPointerException 
    at Multimodality.controller.ExaminationDisplayerController.SPECTLoad(ExaminationDisplayerController.java:224) 
    at Multimodality.controller.ExaminationDisplayerController.initialize(ExaminationDisplayerController.java:86) 
    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.loadImpl(FXMLLoader.java:2566) 
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441) 
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214) 
    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 Multimodality.controller.ExaminationOverviewController.showExaminationDisplayer(ExaminationOverviewController.java:352) 
    at Multimodality.controller.ExaminationOverviewController.btnChooseExaminationsAction(ExaminationOverviewController.java:341) 
    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$MethodHandler.invoke(FXMLLoader.java:1769) 
    at javafx.fxml.FXMLLoader$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$MouseEventNotification.run(GlassViewEventHandler.java:381) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:417) 
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389) 
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416) 
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555) 
    at com.sun.glass.ui.View.notifyMouse(View.java:937) 
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) 
    at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191) 
    at java.lang.Thread.run(Thread.java:745) 

BUILD SUCCESSFUL 

Total time: 52.909 secs 

Ich hoffe, dass einige von euch kann mir helfen! Vielen Dank im Voraus :-)

Answer 1

Immer wenn Sie eine Anforderung haben und Sie Ihre Kontrollen public machen müssen, ist es ein Code-Geruch. Setzen Sie Ihre UI-Knoten niemals frei.

Der beste Weg, dies zu tun wäre, eine Methode in der AdjustmentBarController hinzufügen, um ein Bild zu akzeptieren. Diese Methode würde dann dieses Bild in der ImageView festlegen, die im Controller definiert ist.

public class AdjustmentBarController { 

    ... 

    @FXML 
    private ImageView imgView; 
    ... 
    public void setImage(Image image) { 
     imgView.setImage(image); 
    } 
} 

Nun, sobald dies erledigt ist. Erweitern Sie nicht die ExaminationDisplayerController von AdjustmentBarController.

Laden Sie für jedes Bild, das Sie in ExaminationDisplayerController laden, die FXML-Datei für AdjustmentBar, holen Sie den Controller vom FXMLLoader und stellen Sie das Image im Controller ein.

// Do not extend from AdjustmentBarController 
public class ExaminationDisplayerController { 

    ... 

    public void SPECTLoad() throws SQLException, ClassNotFoundException { 
     DBConnection dbConn = new DBConnection(); 
     ... 
     Image image = new Image(new File("SPECT_IMAGE.jpg").toURI().toString(), 200, 200, true, true); 
     FXMLLoader loader = new FXMLLoader(getClass().getResource("/fxml/AdjustmentBar.fxml")); 
     AnchorPane anchorPaneFromAdjustmentBar = loader.load(); 
     anchorPane.getChildren().add(anchorPaneFromAdjustmentBar); 
     // Get the controller from the FXMLLoader 
     AdjustmentBarController controller = (AdjustmentBarController) loader.getController(); 
     // Set the image 
     controller.setImage(image); 
     ... 
    } 
} 

Für weitere Informationen, gehen Sie durch:

• JavaFX : Pass parameters while instantiating controller class (speziell für Ihren Anwendungsfall)
• Passing Parameters JavaFX FXML (allgemeiner Ansatz)