Javafx将多个imageView添加到scrollpanel会使应用程序爬行

Question

我一直在学习JavaFX。

我制作的一个样本是图像查看器 显示文件夹中的所有图像。

然而，应用程序运行速度非常慢，在任务管理器中需要900-1000MB内存。

将图像逐个添加到数组中效果更好，但仍然不如它应该的那么快。

理想情况下，我希望它能显示至少200-300张图像

任何保持记忆力的方法，也许不会让所有东西都爬行

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.ScrollPane;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.Priority;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

import java.io.*;
import java.net.MalformedURLException;
import java.util.ArrayList;

public class Main extends Application {
    ArrayList<File> files = new ArrayList<>();
    final ScrollPane sp = new ScrollPane();
    final VBox vb = new VBox();
    final Label fileName = new Label();
    /*final File [] imageNames = new File[]{
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 01.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 02.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 03.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 04.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 05.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 06.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 07.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 08.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 09.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 10.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 11.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 12.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 13.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 14.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 15.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 16.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 17.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 18.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 19.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 20.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 21.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 22.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 23.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 24.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 25.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 26.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 27.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 28.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 29.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 30.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 31.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 32.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 33.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 34.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 35.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 36.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 37.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 38.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 39.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 40.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 41.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 42.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 43.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 44.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 45.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 46.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 47.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 48.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 49.jpg"),
            new File("C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images\\08-05-10 01 50.jpg")
    };
    final Image[] images = new Image[imageNames.length];
    final ImageView[] pics = new ImageView[imageNames.length];
*/
    @Override
    public void start(Stage stage) {
        VBox box = new VBox();
        Scene scene = new Scene(box, 600, 400);
        stage.setScene(scene);
        stage.setTitle("Scroll Pane");
        box.getChildren().addAll(sp, fileName);
        VBox.setVgrow(sp, Priority.ALWAYS);
/*       
        for (int i = 0; i < imageNames.length; i++) {
            try {
                images[i] = new Image(imageNames[i].toURI().toURL().toString());
            } catch (MalformedURLException e) {
                e.printStackTrace();
            }
            pics[i] = new ImageView(images[i]);
           // pics[i].setFitWidth(100);
            pics[i].setPreserveRatio(true);
            vb.getChildren().add(pics[i]);
        }*/
        initialize();
        //sp.setVmax(440);
        //sp.setPrefSize(100, 100);
        sp.setContent(vb);
        stage.show();
    }
     void initialize(){
        getImages(new File( "C:\\Users\\user\\IdeaProjects\\untitled\\src\\sample\\images"));

        for(File file: files){
            addImage(file);

        }
        files.clear();
    }

    void addImage(File f){
        // load the image
        Image image = null;
        try {
            //FileInputStream inputStream=new FileInputStream(f);
            image = new Image(f.toURI().toURL().toString());
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }

        ImageView iv = new ImageView();
        iv.setImage(image);
        //iv.setFitWidth(100);
        iv.setPreserveRatio(true);
        iv.setSmooth(true);
        iv.setCache(true);

        vb.getChildren().add(iv);
    }

    void getImages(File dir) {
        if (dir.isDirectory()) {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++) {
                getImages(new File(dir, children[i]));
            }
        }else
        {
            files.add(dir);

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

Answer 1

你的影像有多大？例如，如果一个图像大约10 MB，那么100个图像将解释您的内存使用情况...... 我用大约200张图片测试了它，占用了大约1.9 GB的空间。 当然，如果你加载它们的原始大小，它将会很慢。 但您可以在加载期间指定图像大小：

void addImage(File f) {
    // load the image
    Image image = null;
    try {
        // much better memory footprint
        image = new Image(f.toURI().toURL().toString(),400,400,true, true, true);
        //image = new Image(f.toURI().toURL().toString()); // bad idea with many big images
    } catch (MalformedURLException e) {
        e.printStackTrace();
    }

    ImageView iv = new ImageView();
    iv.setImage(image);
    iv.setPreserveRatio(true);
    iv.setSmooth(true);
    iv.setCache(true);

    vb.getChildren().add(iv);
}