如何在 javafx 中保存选定的图像？

Question

like this blank image is saving

 import java.io.File;
    import java.io.IOException;
    import javafx.application.Application;
    import javafx.embed.swing.SwingFXUtils;
    import javafx.event.EventHandler;
    import javafx.scene.Scene;
    import javafx.scene.SnapshotParameters;
    import javafx.scene.effect.Light.Point;
    import javafx.scene.image.WritableImage;
    import javafx.scene.input.KeyCode;
    import javafx.scene.input.KeyEvent;
    import javafx.scene.layout.Pane;
    import javafx.scene.paint.Color;
    import javafx.scene.shape.Rectangle;
    import javafx.scene.web.WebEngine;
    import javafx.scene.web.WebView;
    import javafx.stage.Stage;
    import javax.imageio.ImageIO;

public class JavaFxSelectPlay extends Application {

    public static void main(String[] args) {
        launch();
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        Pane root = new Pane();
        WebView wv = new WebView();
        WebEngine Img = wv.getEngine();
        Img.load("https://app.leadlock.pro/upload/69/1019/images/welcome.jpeg");
        final Rectangle selection = new Rectangle();
        final Point anchor = new Point();

        wv.setOnMousePressed(event -> {
            anchor.setX(event.getX());
            anchor.setY(event.getY());
            selection.setX(event.getX());
            selection.setY(event.getY());
            selection.setFill(null); // transparent 
            selection.setStroke(Color.BLACK); // border
            selection.getStrokeDashArray().add(10.0);
         root.getChildren().add(selection);
        });

        wv.setOnMouseDragged(event -> {
            selection.setWidth(Math.abs(event.getX() - anchor.getX()));
            selection.setHeight(Math.abs(event.getY() - anchor.getY()));
            selection.setX(Math.min(anchor.getX(), event.getX()));
            selection.setY(Math.min(anchor.getY(), event.getY()));
        });

        wv.setOnMouseReleased(event -> {
            // Do what you want with selection's properties here
            System.out.printf("X: %.2f, Y: %.2f, Width: %.2f, Height: %.2f%n", 
                    selection.getX(), selection.getY(), selection.getWidth(), selection.getHeight());
          //  root.getChildren().remove(selection);
           // selection.setWidth(0);
          //  selection.setHeight(0);
        });
          wv.addEventFilter(KeyEvent.KEY_RELEASED, (KeyEvent e1) -> {
            if (e1.getCode() == KeyCode.SPACE ) {
     selection.setFill(Color.WHITE); // transparent 
            }
            });
          wv.setOnKeyPressed(new EventHandler<KeyEvent>() {
 public void handle(final KeyEvent keyEvent) {
   if (keyEvent.getCode() == KeyCode.F5) {
    System.out.println("F5 pressed");
    //Stop letting it do anything else
   // WritableImage croppedImage = selection.snapshot(null, null);


           WritableImage image = selection.snapshot(new SnapshotParameters(), null);

    // TODO: probably use a file chooser here
     File file = new File("C:/temp/snapshot.jpg");

    try {
        ImageIO.write(SwingFXUtils.fromFXImage(image, null), "jpg", file);
    } catch (IOException e) {
        // TODO: handle exception here
    }
}
            System.out.println("snapshot saved: " );
   }
 });

        root.getChildren().add(wv);
        Scene scene = new Scene(root, 300, 200);
        primaryStage.setScene(scene);
        primaryStage.setTitle("Primary Stage");
        primaryStage.show();
    }
 }

这个代码我试过了，它运行很好，但是保存的图像是用白色保存的，它没有保存原始选择的图像，所以我该怎么做，请帮助我保存选择的图像我做了白色但不是白色而是选择的图像所以请告诉我怎么做以及我做错了什么。

Answer 1

这里似乎发生了两件事。

首先，您可能不想拍摄用于标记选择的 Rectangle 的快照，而是拍摄根的快照并使用选择矩形指定快照的哪一部分拿。所以，而不是写

        WritableImage image = selection.snapshot(new SnapshotParameters(), null);

尝试写作

        SnapshotParameters params = new SnapshotParameters();
        params.setViewport(
            new Rectangle2D(
                selection.getX(),
                selection.getY(),
                selection.getWidth(),
                selection.getHeight()));

        root.getChildren().remove(selection);
        WritableImage image = root.snapshot(params, null);

我还从根部删除了矩形，这样它就不会出现在输出图像中。

发生的第二件事是图像变成粉红色。这似乎是一个 existing issue which is supposed to have been fixed in Java 8 但我仍然可以在 Java 8 update 152 中重现它。调整我链接到的问题中的代码，你将不得不替换行

            ImageIO.write(SwingFXUtils.fromFXImage(image, null), "jpg", file);

和

            BufferedImage bufferedImage = SwingFXUtils.fromFXImage(image, null);
            BufferedImage imageRGB = new BufferedImage(
                bufferedImage.getWidth(), bufferedImage.getHeight(), BufferedImage.OPAQUE);
            Graphics2D graphics = imageRGB.createGraphics();
            graphics.drawImage(bufferedImage, 0, 0, null);
            ImageIO.write(imageRGB, "jpg", file);

如何在 javafx 中保存选定的图像？

How to save selected image in javafx?

java

javafx

selection