进度条在javafx下载图像时

2 回答

• 1

  这个答案回答你的问题 Headers ：“在javafx下载图像时进度条” .

  你的问题中的代码有点不清楚，所以答案可能会也可能不会回答你真正希望实现的目标 .

  

  • 在background中加载图像 .

  • 将ProgressBar的progress属性绑定到图像的progessProperty .

  注意：对于示例代码和图像，图像加载速度非常快，因此您实际上看不到进度条的移动 . 对于正在加载的非常大的图像和非常慢的Internet连接，您可能会看到进度条随着加载的进行而移动 .

  import javafx.application.Application;
  import javafx.scene.Scene;
  import javafx.scene.control.ProgressBar;
  import javafx.scene.image.*;
  import javafx.scene.layout.VBox;
  import javafx.stage.Stage;
  
  public class ImageLoadProgress extends Application {
  
      private static final String IMAGE_LOC =
              "http://icons.iconarchive.com/icons/custom-icon-design/flatastic-10/128/Bear-icon.png";
  
      @Override
      public void start(Stage stage) throws Exception {
          Image image = new Image(IMAGE_LOC, true);
          ProgressBar bar = new ProgressBar();
          bar.progressProperty().bind(image.progressProperty());
  
          ImageView imageView = new ImageView(image);
          imageView.setFitWidth(128);
          imageView.setFitHeight(128);
          stage.setScene(new Scene(new VBox(5, bar, imageView)));
          stage.show();
      }
  
      public static void main(String[] args) {
          launch(args);
      }
  }
  

  更新其他问题

  如何创建一个包含多个图像下载和一个进度条的任务？

  使用DoubleExpression，它映射到所有图像的背景加载进度的平均值 .

  

  import javafx.application.Application;
  import javafx.beans.binding.DoubleExpression;
  import javafx.beans.property.SimpleDoubleProperty;
  import javafx.scene.Scene;
  import javafx.scene.control.ProgressBar;
  import javafx.scene.image.Image;
  import javafx.scene.image.ImageView;
  import javafx.scene.layout.VBox;
  import javafx.stage.Stage;
  
  import java.util.Arrays;
  import java.util.stream.Collectors;
  
  public class ImagesLoadProgress extends Application {
  
      private static final String IMAGE_PATH_PREFIX =
              "http://icons.iconarchive.com/icons/custom-icon-design/flatastic-10/128/";
  
      private static final String[] IMAGES_FILENAMES = {
              "Bear-icon.png",
              "Bow-icon.png",
              "Sport-american-football-icon.png",
              "Sport-baseball-icon.png"
      };
  
      @Override
      public void start(Stage stage) throws Exception {
          Image[] images =
                  Arrays.stream(IMAGES_FILENAMES)
                  .map(filename -> new Image(IMAGE_PATH_PREFIX + filename, true))
                  .toArray(Image[]::new);
  
          DoubleExpression totalImageDownloadProgress;
          if (images.length > 0) {
              totalImageDownloadProgress = new SimpleDoubleProperty(0);
              for (Image image: images) {
                  totalImageDownloadProgress = totalImageDownloadProgress.add(image.progressProperty());
              }
              totalImageDownloadProgress = totalImageDownloadProgress.divide(IMAGES_FILENAMES.length);
          } else {
              totalImageDownloadProgress = new SimpleDoubleProperty(1);
          }
  
  
          ProgressBar bar = new ProgressBar();
          bar.progressProperty().bind(totalImageDownloadProgress);
  
          VBox layout = new VBox(5, bar);
  
          Arrays.stream(images)
                  .map(this::createImageView)
                  .collect(Collectors.toCollection(layout::getChildren));
  
          stage.setScene(new Scene(layout));
          stage.show();
      }
  
      private ImageView createImageView(Image image) {
          ImageView imageView = new ImageView(image);
          imageView.setFitWidth(128);
          imageView.setFitHeight(128);
  
          return imageView;
      }
  
      public static void main(String[] args) {
          launch(args);
      }
  }
  

  上面的解决方案没有考虑到error conditions for images that fail to load，但我会给你添加这样的逻辑（主要是监视错误属性并调整加载进度的平均计算，使其不包括那些无法加载的图像） .

  回复于 2024-05-11T05:25:45+08:00
• 0

  谢谢你们的帮助，我找到了答案：

  final Task<ArrayList<Image>> task = new Task<ArrayList<Image>>() {
              @Override protected ArrayList<Image> call() throws Exception {
  
                  int id = Data_model.getInstance().currentid();
  
                  All_photos photos = (All_photos) new parse_object <All_photos> (All_photos.class).ParseUri("https://api.edmunds.com/api/media/v2/styles/"+id+"/photos?api_key=id&fmt=json");
  
                  ArrayList<String> list_href = new SlideShowHelper().get_href(photos);
  
                  ArrayList<Image> list = new ArrayList<Image>();
  
                  int i = 1;
  
                              for ( String st:list_href)
                              {
  
                                  System.out.println(st);
                                  list.add(new Image("https://media.ed.edmunds-media.com"+st+"",true));
                                  updateProgress(i, list_href.size());
                                  Thread.sleep(400);
                                  i++;
  
  
                              }
                              return list;
              }
  
  
               @Override protected void succeeded() {
  
                   super.succeeded();
  
                   updateProgress(10, 10);
  
                   img_slideshow.setImage(Images.get(0));
  
                   int count1 =count+1;
  
                   lbl_slideshow.setText(""+count1+" / "+Images.size()+"");
  
                   progress_sd.setVisible(false);  
  
                   btn_sd_back.setVisible(true);
                   btn_sd_next.setVisible(true);
  
  
               }
  
  
           };
  
          task.addEventHandler(WorkerStateEvent.WORKER_STATE_SUCCEEDED,new EventHandler<WorkerStateEvent>() {
  
              public void handle(WorkerStateEvent t) {
                  Images = task.getValue();
  
              }
          });
  
      new Thread(task).start();
  
  
      //progress_sd.visibleProperty().bind(task.runningProperty());
  
      progress_sd.progressProperty().bind(task.progressProperty());
  
  }
  

  它工作，但是？好吗 ？

  回复于 2024-05-11T05:25:45+08:00