时间轴在幻灯片中逐个显示随机图像 [英] Timeline to Display Random images one by one in a slideshow

问题描述

我想逐个随机显示我的图片。以下代码仅在我将持续时间以秒为单位时逐个显示图像：

I want to display my images randomly one by one. The code below displays images one by one only if i put the duration time in seconds like:

 new KeyFrame(Duration.seconds(1), new KeyValue(imageView.imageProperty(), image1)),
 new KeyFrame(Duration.seconds(2), new KeyValue(imageView.imageProperty(), image2)),
 new KeyFrame(Duration.seconds(3), new KeyValue(imageView.imageProperty(), image3)),
 new KeyFrame(Duration.seconds(4), new KeyValue(imageView.imageProperty(), image4)),

因此，我的代码将显示image1 firstn image 2秒，image3 thirds等等。

So, my code will display image1 firstn image 2 second, image3 thirds and so on.

1）我希望它每次都能显示随机图像。

2）不依赖于持续时间。因为如果我把 Duration.seconds（3）添加到所有这些，它将只显示第一个。

1) I want it to display random images every time.
2) Not to depend on duration time . Because if i put Duration.seconds(3) to all of them it will display just the first one.

代码如下所示：

package imagedisplayy;

import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.util.Duration;
/**
 *
 * @author D
 */
public class ImageDisplayy extends Application {

    @Override
    public void start(Stage primaryStage) {
        Image image1 = new Image("file:lib/1.jpg");
        Image image2 = new Image("file:lib/2.jpg");
        Image image3 = new Image("file:lib/3.jpg");
        Image image4 = new Image("file:lib/4.jpg");
        ImageView imageView = new ImageView();
        Timeline timeline = new Timeline(

                new KeyFrame(Duration.seconds(3), new KeyValue(imageView.imageProperty(), image1)),
                new KeyFrame(Duration.seconds(3), new KeyValue(imageView.imageProperty(), image2)),  
                new KeyFrame(Duration.seconds(3), new KeyValue(imageView.imageProperty(), image3)),
                new KeyFrame(Duration.seconds(3), new KeyValue(imageView.imageProperty(), image4)),   
                new KeyFrame(Duration.seconds(3), new KeyValue(imageView.imageProperty(), null))
                );
        timeline.play();
        StackPane root = new StackPane();
        root.getChildren().add(imageView);
        primaryStage.setScene(new Scene(root, 800, 600));
        primaryStage.show();
    }

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

推荐答案

这里是一种基于数组的解决方案，循环显示随机选择的图像。阵列中的所有图像将以随机顺序显示一次，然后阵列将被混洗，允许所有图像以不同的随机顺序再次显示。

Here is an array based solution that cycles displaying a random choice of images. All images in the array will be displayed once in random order, then the array will be shuffled, allowing all images to be displayed again in a different random order.

import javafx.animation.*;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.image.*;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.util.Duration;

import java.util.*;
import java.util.stream.Collectors;

public class ImageDisplay extends Application {

    private List<Image> images;
    private Iterator<Image> imageIterator;

    @Override
    public void start(Stage stage) {
        images = Arrays.stream(IMAGE_LOCS)
                .map(Image::new)
                .collect(Collectors.toList());
        Collections.shuffle(images);
        imageIterator = images.iterator();
        ImageView imageView = new ImageView();

        Timeline timeline = new Timeline(
                new KeyFrame(
                        Duration.ZERO,
                        e -> {
                            imageView.setImage(imageIterator.next());
                            System.out.println(
                                 "Displaying " + imageView.getImage().impl_getUrl()
                            );
                        }
                ),
                new KeyFrame(Duration.seconds(1))
        );
        timeline.setCycleCount(images.size());
        timeline.setOnFinished(event -> {
            Collections.shuffle(images);
            imageIterator = images.iterator();
            timeline.playFromStart();
        });
        timeline.play();

        StackPane layout = new StackPane(imageView);
        stage.setScene(new Scene(layout));
        stage.show();
    }

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

    // image license: linkware - backlink to http://www.fasticon.com
    private static final String[] IMAGE_LOCS = {
        "http://icons.iconarchive.com/icons/fasticon/fish-toys/128/Blue-Fish-icon.png",
        "http://icons.iconarchive.com/icons/fasticon/fish-toys/128/Red-Fish-icon.png",
        "http://icons.iconarchive.com/icons/fasticon/fish-toys/128/Yellow-Fish-icon.png",
        "http://icons.iconarchive.com/icons/fasticon/fish-toys/128/Green-Fish-icon.png"
    };
}

因为我们每次都会洗牌，所以显示的最后一张图片可能是洗牌成为下一个周期的第一个图像（连续两次显示）。如果您不希望顺序在循环之间更改，只需删除时间完成播放时执行的随机播放命令。

Because we shuffle each time, it is possible for the last image displayed to be shuffled to be the first image on the next cycle (displaying it twice in a row). If you don't want the order to change between cycles, just remove the shuffle command executed when the time completes playing.

注意，为简单起见，代码使用 impl_getUrl（）将显示的图像URL的日志输出到控制台 - 不建议在生产代码中使用impl方法。

Note, for simplicity, the code uses impl_getUrl() to output a log of displayed image urls to the console - use of impl methods is not recommended in production code.

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