为了在 JavaFX 中的 ImageView 上进行转换

Question

我已经看过How to wait for a transition to end in javafx 2.1?，但它并没有完全解决我的问题。

我有一个 ImageView 对象列表，我想遍历此列表并在列表的每个“幻灯片”上执行以下操作：

1. 淡入
2. 停留几秒钟
3. 淡出

我有以下代码，但由于过渡是异步的，因此循环将过渡同时应用于所有“幻灯片”：

// The method I am running in my class

public void start() {

    for (ImageView slide : slides) {

        SequentialTransition sequentialTransition = new SequentialTransition();

        FadeTransition fadeIn = Transition.getFadeTransition(slide, 0.0, 1.0, 2000);
        FadeTransition stayOn = Transition.getFadeTransition(slide, 1.0, 1.0, 2000);
        FadeTransition fadeOut = Transition.getFadeTransition(slide, 1.0, 0.0, 2000);

        sequentialTransition.getChildren().addAll(fadeIn, stayOn, fadeOut);               
        this.root.getChildren().add(slide);            
        sequentialTransition.play();

    }
}

// the method in the Transition helper class:

public static FadeTransition getFadeTransition(ImageView imageView, double fromValue, double toValue, int durationInMilliseconds) {

    FadeTransition ft = new FadeTransition(Duration.millis(durationInMilliseconds), imageView);
    ft.setFromValue(fromValue);
    ft.setToValue(toValue);

    return ft;

}

关于如何对这些 ImageView 对象列表进行动画处理的任何想法（与列表中的 ImageView 数量无关，因此我不想对其进行硬编码）。谢谢。

Answer 1

因此，对此的明显解决方法是为您的 SequentialTransition 使用环绕的 SequentialTransition 来播放这些转换，嗯，顺序而不是一次全部播放：

public void start() {

    SequentialTransition slideshow = new SequentialTransition();

    for (ImageView slide : slides) {

        SequentialTransition sequentialTransition = new SequentialTransition();

        FadeTransition fadeIn = Transition.getFadeTransition(slide, 0.0, 1.0, 2000);
        FadeTransition stayOn = Transition.getFadeTransition(slide, 1.0, 1.0, 2000);
        FadeTransition fadeOut = Transition.getFadeTransition(slide, 1.0, 0.0, 2000);

        sequentialTransition.getChildren().addAll(fadeIn, stayOn, fadeOut);               
        this.root.getChildren().add(slide);            
        slideshow.getChildren().add(sequentialTransition);

    }
    slideshow.play();
}

其次，您应该使用 PauseTransition 而不是从 1.0 插入到 1.0 的 FadeTransition。

一个完整的示例应用程序可能如下所示：

package slideshow;

import javafx.animation.FadeTransition;
import javafx.animation.PauseTransition;
import javafx.animation.SequentialTransition;
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;

public class SimpleSlideShowTest extends Application{

  class SimpleSlideShow {

    StackPane root = new StackPane();
    ImageView[] slides;

    public SimpleSlideShow() {
      this.slides = new ImageView[4];
      Image image1 = new Image(SlideShowTest.class.getResource("pic1").toExternalForm());
      Image image2 = new Image(SlideShowTest.class.getResource("pic2").toExternalForm());
      Image image3 = new Image(SlideShowTest.class.getResource("pic3").toExternalForm());
      Image image4 = new Image(SlideShowTest.class.getResource("pic4").toExternalForm());
      slides[0] = new ImageView(image1);
      slides[1] = new ImageView(image2);
      slides[2] = new ImageView(image3);
      slides[3] = new ImageView(image4);

    }

    public StackPane getRoot() {
      return root;
    }

    // The method I am running in my class

    public void start() {

      SequentialTransition slideshow = new SequentialTransition();

      for (ImageView slide : slides) {

        SequentialTransition sequentialTransition = new SequentialTransition();

        FadeTransition fadeIn = getFadeTransition(slide, 0.0, 1.0, 2000);
        PauseTransition stayOn = new PauseTransition(Duration.millis(2000));
        FadeTransition fadeOut = getFadeTransition(slide, 1.0, 0.0, 2000);

        sequentialTransition.getChildren().addAll(fadeIn, stayOn, fadeOut);
        slide.setOpacity(0);
        this.root.getChildren().add(slide);
        slideshow.getChildren().add(sequentialTransition);

      }
      slideshow.play();
    }

// the method in the Transition helper class:

    public FadeTransition getFadeTransition(ImageView imageView, double fromValue, double toValue, int durationInMilliseconds) {

      FadeTransition ft = new FadeTransition(Duration.millis(durationInMilliseconds), imageView);
      ft.setFromValue(fromValue);
      ft.setToValue(toValue);

      return ft;

    }
  }

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

  @Override
  public void start(Stage primaryStage) throws Exception {
    SimpleSlideShow simpleSlideShow = new SimpleSlideShow();
    Scene scene = new Scene(simpleSlideShow.getRoot());
    primaryStage.setScene(scene);
    primaryStage.show();
    simpleSlideShow.start();
  }
}