使用Facebook的壁画加载位图 [英] Using Facebook's Fresco to load a bitmap

问题描述

我试图用壁画取代我的Android应用程序中的毕加索。然而，我不知道如何使用Fresco来简单加载位图。

毕加索我只会执行以下操作。

 位图Poster = Picasso.with（getActivity（））
 .load（url）
 .resize （Utils.convertDpToPixel（WIDTH，HEIGHT））
 .centerCrop（）
 .get（）; 
  

我一直无法弄清楚如何使用此壁画创建位图。有任何想法吗？

解决方案

如Fresco所说：

如果您对管道的请求是一个解码的图像 - 一个Android Bitmap，您可以利用我们更容易使用的BaseBitmapDataSubscriber：

  dataSource.subscribe （新的BaseBitmapDataSubscriber（）{
 @Override 
 public void onNewResultImpl（@Nullable Bitmap bitmap）{
 //您可以使用有限的方式
 //不需要做任何清理
} 
 
 @Override 
 public void onFailureImpl（DataSource dataSource）{
 //此处不需要清理
} 
}，
执行者）; 
  

您不能将位图分配给不在onNewResultImpl方法范围内的任何变量。

http：// frescolib。 org / docs / datasources-dataubscribers.html＃_

我的代码：

  public void setDataSubscriber（Context context，Uri uri，int width，int height）{
 DataSubscriber dataSubscriber = new BaseDataSubscriber< CloseableReference< CloseableBitmap>（）{
 @Override 
 public void onNewResultImpl（
 DataSource< CloseableReference< CloseableBitmap>> dataSource）{
 if（！dataSource.isFinished（））{
 return; 
} 
 CloseableReference< CloseableBitmap> imageReference = dataSource.getResult（）; 
 if（imageReference！= null）{
 final CloseableReference< CloseableBitmap> closeableReference = imageReference.clone（）; 
 try {
 CloseableBitmap closeableBitmap = closeableReference.get（）; 
 Bitmap bitmap = closeableBitmap.getUnderlyingBitmap（）; 
 if（bitmap！= null&！bitmap.isRecycled（））{
 //你可以在这里使用位图
} 
} finally {
 imageReference 。关（）; 
 closeableReference.close（）; 
} 
} 
} 
 @Override 
 public void onFailureImpl（DataSource dataSource）{
 Throwable throwable = dataSource.getFailureCause（）; 
 //处理失败
} 
}; 
 getBitmap（context，uri，width，height，dataSubscriber）; 
} 
 
 / ** 
 * 
 * @param上下文
 * @param uri 
 * @param width 
 * @param height 
 * @param dataSubscriber 
 * / 
 public void getBitmap（Context context，Uri uri，int width，int height，DataSubscriber dataSubscriber）{
 ImagePipeline imagePipeline = Fresco。 getImagePipeline（）; 
 ImageRequestBuilder builder = ImageRequestBuilder.newBuilderWithSource（uri）; 
 if（width> 0&&& height> 0）{
 builder.setResizeOptions（new ResizeOptions（width，height））; 
} 
 ImageRequest request = builder.build（）; 
 DataSource< CloseableReference< CloseableImage>> 
 dataSource = imagePipeline.fetchDecodedImage（request，context）; 
 dataSource.subscribe（dataSubscriber，UiThreadExecutorService.getInstance（））; 
} 
  

I'm trying to replace Picasso in my android app with Fresco. However I am unsure of how to simply load a bitmap using Fresco.

With Picasso I would just do the following.

Bitmap poster = Picasso.with(getActivity())
                    .load(url)
                    .resize(Utils.convertDpToPixel(WIDTH,HEIGHT))
                    .centerCrop()
                    .get();

I have been unable to figure out how to create a Bitmap with this Fresco. Any ideas?

解决方案

As Fresco said:

If your request to the pipeline is for a decoded image - an Android Bitmap, you can take advantage of our easier-to-use BaseBitmapDataSubscriber:

dataSource.subscribe(new BaseBitmapDataSubscriber() {
    @Override
    public void onNewResultImpl(@Nullable Bitmap bitmap) {
       // You can use the bitmap in only limited ways
      // No need to do any cleanup.
    }

    @Override
    public void onFailureImpl(DataSource dataSource) {
      // No cleanup required here.
    }
  },
  executor);

You can not assign the bitmap to any variable not in the scope of the onNewResultImpl method.

http://frescolib.org/docs/datasources-datasubscribers.html#_

My code :

public void setDataSubscriber(Context context, Uri uri, int width, int height){
    DataSubscriber dataSubscriber = new BaseDataSubscriber<CloseableReference<CloseableBitmap>>() {
        @Override
        public void onNewResultImpl(
                DataSource<CloseableReference<CloseableBitmap>> dataSource) {
            if (!dataSource.isFinished()) {
                return;
            }
            CloseableReference<CloseableBitmap> imageReference = dataSource.getResult();
            if (imageReference != null) {
                final CloseableReference<CloseableBitmap> closeableReference = imageReference.clone();
                try {
                    CloseableBitmap closeableBitmap = closeableReference.get();
                    Bitmap bitmap  = closeableBitmap.getUnderlyingBitmap();
                    if(bitmap != null && !bitmap.isRecycled()) {
                        //you can use bitmap here
                    }
                } finally {
                    imageReference.close();
                    closeableReference.close();
                }
            }
        }
        @Override
        public void onFailureImpl(DataSource dataSource) {
            Throwable throwable = dataSource.getFailureCause();
            // handle failure
        }
    };
    getBitmap(context, uri, width, height, dataSubscriber);
}

/**
 *
 * @param context
 * @param uri
 * @param width          
 * @param height         
 * @param dataSubscriber
 */
public void getBitmap(Context context, Uri uri, int width, int height, DataSubscriber dataSubscriber){
    ImagePipeline imagePipeline = Fresco.getImagePipeline();
    ImageRequestBuilder builder = ImageRequestBuilder.newBuilderWithSource(uri);
    if(width > 0 && height > 0){
        builder.setResizeOptions(new ResizeOptions(width, height));
    }
    ImageRequest request = builder.build();
    DataSource<CloseableReference<CloseableImage>>
            dataSource = imagePipeline.fetchDecodedImage(request, context);
    dataSource.subscribe(dataSubscriber, UiThreadExecutorService.getInstance());
}

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