来自另一个FXML控制器的ImageView的Javafx setImage

来自另一个FXML控制器的ImageView的Javafx setImage,java,javafx,fxml,scenebuilder,Java,Javafx,Fxml,Scenebuilder,我有一个名为“AdjustmentBar”的类,它包括一个imageView、一个菜单栏和一些图片编辑功能(一个FXML文件和一个控制器)。AdjustmentBar被加载到另一个名为“ExamicationDisplayer”的类(也是一个FXML文件和一个控制器)。ExaminationDisplayer从一个在线MySQL数据库加载一些图像,我希望这些图像中的每一个都显示在一个单独的imageView中 我已经能够将AdjustmentBar加载到ExaminationalDisplaye

我有一个名为“AdjustmentBar”的类,它包括一个imageView、一个菜单栏和一些图片编辑功能(一个FXML文件和一个控制器)。AdjustmentBar被加载到另一个名为“ExamicationDisplayer”的类(也是一个FXML文件和一个控制器)。ExaminationDisplayer从一个在线MySQL数据库加载一些图像,我希望这些图像中的每一个都显示在一个单独的imageView中

我已经能够将AdjustmentBar加载到ExaminationalDisplayer中,但是我不知道如何设置AdjustmentBar中包含的imageView的image()。我可以在检查显示器中专门制作的imageview中显示数据库中的图像,如果单独运行,我可以在AdjustmentBar视图中显示图像。我只是无法让加载的调整栏在检查显示器中显示图像

当我运行它时,我得到了这行代码的nullpointerexception错误:imgView.setImage(image),它位于检查显示器控制器中:

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();
        }
    }
我不确定AdjustmentBar的FXML文件是否相关,但下面是:

<?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>

我希望你们中的一些人能帮助我!提前感谢:-)

每当您有要求并且需要将控件公开时,这就是代码气味。永远不要暴露你的UI节点

最好的方法是在
AdjustmentBarController
中添加一个方法来接受图像。然后,此方法将在控制器中定义的ImageView中设置此图像

public class AdjustmentBarController {

    ...

    @FXML
    private ImageView imgView;
    ...
    public void setImage(Image image) {
        imgView.setImage(image);
    }
}
// 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);
        ...
    }
}
现在,一旦这样做了。不要从
AdjustmentBarController
扩展
检查显示器控制器

对于在
检查显示器控制器
中加载的每个图像,加载
调整栏
的FXML文件,从FXMLLoader中取出控制器并在控制器中设置图像

public class AdjustmentBarController {

    ...

    @FXML
    private ImageView imgView;
    ...
    public void setImage(Image image) {
        imgView.setImage(image);
    }
}
// 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);
        ...
    }
}
有关更多信息,请浏览:

  • (特定于您的用例)
  • (一般做法)

有两条语句让我感到困惑——“AdjustmentBar被加载到另一个名为“ExaminationalDisplayer”的类中”和“我已经能够将AdjustmentBar加载到ExaminationalDisplayer中”"? 此外,我可以看到您的检查显示器控制器扩展了AdjustmentBarController,但它似乎不正确。你能解释一下你想在这里实现什么吗?@ItachiUchiha嗨!是的,检查显示器从数据库加载图片,并应在imageView中显示。但是,我不希望它只是一个常规的图像视图,而是应该是我在AdjustmentBar中设计的一个,因为它还有一个工具栏,允许我缩放/旋转/调整每个图像视图的对比度。我无法调用imgView(它是AdjustmentBar的ImageView的fixID),除非我添加了“extend”命令——但这可能根本不对。我希望这是有意义的!我还添加了我在帖子中遇到的错误。:-)@ItachiUchiha也就是说,我有一个名为ExaminationalDisplayer的FXML文件,它加载/打开/显示另一个名为AdjustmentBar的FXML文件。将加载多少AdjustmentBar ImageView取决于一次要显示多少图片。它可能只有一个,但通常是三个或四个。这不是继承的工作方式。继承是类之间的关系。当您执行
class AdjustmentBarController{private ImageView imgView;}
时,意味着每个
AdjustmentBarController
实例都有一个名为
imgView
的字段。当您编写
examinationalDisplayerController扩展AdjustmentBarController
时,这意味着每个
examinationalDisplayerController
实例也是
AdjustmentBarController
的实例(这没有意义),因此,每个
检查DisplayerController
实例也有一个
imgView
字段。(1/2)但这并不意味着一个实例中的
imgView
字段以某种方式设置为与另一个实例中的
imgView
字段相同的值。这里有两个控制器:一个是
检查显示器控制器
的实例,一个是
调整栏控制器
的实例。按照您的方式(同样,这没有意义),每一个都有自己的
imgView
字段。仅仅因为该字段在一个实例中被设置为非null值,在另一个实例中并不会以某种方式使其成为非null值。(2/2)谢谢你,这很有帮助!我试着用你的代码从我的项目中加载一个现有的图像文件,效果非常好。但不幸的是,我仍然无法显示SPECT_IMAGE.jpg。我想那一定是因为别的原因,所以我要做一些研究,看看哪里可能是错的。再次感谢你!完成研究后,请随时在下面的评论中提出任何其他问题。@Heidi image具有和属性,请尝试向它们添加侦听器或查询它们以查看是否有图像加载错误。@ItachiUchiha我只需要添加“I”到映像的路径-典型的初学者错误:-)映像映像=新映像(新文件(i+“SPECT_image.jpg”).toURI().toString());