在JavaFX中调整窗口大小时如何调整图像大小

Question

我有下面的代码，它设置了一个特定大小的窗口。它还从外部URL加载图像。

@Override
public void start(Stage primaryStage) {

    MenuBar menuBar=new MenuBar();
    Menu menuGame = new Menu("Game");
    MenuItem newGame = new MenuItem("New Game                F1");
    MenuItem exit = new MenuItem("Exit                            F2");
    exit.setOnAction(new EventHandler<ActionEvent>() {

        @Override
        public void handle(ActionEvent event) {
            primaryStage.close();
        }

    });
    menuGame.getItems().addAll(newGame,new SeparatorMenuItem(),exit);
    menuBar.getMenus().addAll(menuGame);

    Image image = new Image("http://docs.oracle.com/javafx/"
    + "javafx/images/javafx-documentation.png");
    ImageView imageView = new ImageView();
    imageView.setImage(image);


    VBox vbox=new VBox();
    StackPane root=new StackPane();
    root.getChildren().addAll(imageView);

    vbox.getChildren().addAll(menuBar,root);

    Scene scene= new Scene(vbox,400,400);
    primaryStage.setScene(scene);

    primaryStage.setMaxHeight(800);
    primaryStage.setMinHeight(400);
    primaryStage.setMaxWidth(1000);
    primaryStage.setMinWidth(800);

    primaryStage.setTitle("Minesweeper");
    primaryStage.show();

}

Answer 1

将JavaFx图像大小调整的解决方案应用到示例代码中，并调整窗口的大小，对我来说会产生不同的图像大小。

import javafx.application.Application;
import javafx.beans.property.*;
import javafx.beans.value.*;
import javafx.event.*;
import javafx.geometry.HPos;
import javafx.geometry.VPos;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.image.*;
import javafx.scene.layout.*;
import javafx.stage.Stage;

public class ImageResizer extends Application {
    @Override
    public void start(Stage primaryStage) {
        MenuBar menuBar=new MenuBar();
        Menu menuGame = new Menu("Game");
        MenuItem newGame = new MenuItem("New Game                F1");
        MenuItem exit = new MenuItem("Exit                            F2");
        exit.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                primaryStage.close();
            }
        });
        menuGame.getItems().addAll(newGame,new SeparatorMenuItem(),exit);
        menuBar.getMenus().addAll(menuGame);

        Image image = new Image("http://docs.oracle.com/javafx/"
                + "javafx/images/javafx-documentation.png");
        ImageView imageView = new ImageView();
        imageView.setImage(image);

        ImageViewPane viewPane = new ImageViewPane(imageView);

        VBox vbox=new VBox();
        StackPane root=new StackPane();
        root.getChildren().addAll(viewPane);

        vbox.getChildren().addAll(menuBar,root);
        VBox.setVgrow(root, Priority.ALWAYS);

        Scene scene= new Scene(vbox,200,200);
        primaryStage.setScene(scene);

        primaryStage.setMaxHeight(400);
        primaryStage.setMinHeight(200);
        primaryStage.setMaxWidth(500);
        primaryStage.setMinWidth(400);

        primaryStage.setTitle("Minesweeper");
        primaryStage.show();

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





/*
 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 */


/**
 *
 * @author akouznet
 */
class ImageViewPane extends Region {

    private ObjectProperty<ImageView> imageViewProperty = new SimpleObjectProperty<ImageView>();

    public ObjectProperty<ImageView> imageViewProperty() {
        return imageViewProperty;
    }

    public ImageView getImageView() {
        return imageViewProperty.get();
    }

    public void setImageView(ImageView imageView) {
        this.imageViewProperty.set(imageView);
    }

    public ImageViewPane() {
        this(new ImageView());
    }

    @Override
    protected void layoutChildren() {
        ImageView imageView = imageViewProperty.get();
        if (imageView != null) {
            imageView.setFitWidth(getWidth());
            imageView.setFitHeight(getHeight());
            layoutInArea(imageView, 0, 0, getWidth(), getHeight(), 0, HPos.CENTER, VPos.CENTER);
        }
        super.layoutChildren();
    }

    public ImageViewPane(ImageView imageView) {
        imageViewProperty.addListener(new ChangeListener<ImageView>() {

            @Override
            public void changed(ObservableValue<? extends ImageView> arg0, ImageView oldIV, ImageView newIV) {
                if (oldIV != null) {
                    getChildren().remove(oldIV);
                }
                if (newIV != null) {
                    getChildren().add(newIV);
                }
            }
        });
        this.imageViewProperty.set(imageView);
    }
}

基于评论的备选方法和额外信息

如果您必须这样做，那么这是JavaFX平台的一个弱点。理想情况下，我希望在图像上有一个scale属性，可以设置它，这样它就可以使用SceneGraph来确定它的大小。

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if (imageView.isPreserveRatio()) {
    if (getHeight() > getWidth()) {
        imageView.setFitWidth(getWidth());
        imageView.setFitHeight(0);
    } else {
        imageView.setFitWidth(0);
        imageView.setFitHeight(getHeight());
    }
} else {
    imageView.setFitWidth(getWidth());
    imageView.setFitHeight(getHeight());
}