Fresco图片加载框架一些简单使用

最新推荐文章于 2021-05-26 17:59:50 发布

独行者mj

最新推荐文章于 2021-05-26 17:59:50 发布

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CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/u014687525/article/details/52688978

本文介绍了使用Fresco库进行图片加载及处理的方法，包括图片缩放、设置默认图、失败图，以及如何通过定制化的加载流程实现图片的模糊显示等高级特性。

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//图片缓存
SimpleDraweeView photoIV;
String imgUrl;
View itemView;
//初始化配置设置默认图等
photoIV.setHierarchy(createVideoCoverBuilder(itemView.getResources()));
public GenericDraweeHierarchy createVideoCoverBuilder(Resources resources) {
    GenericDraweeHierarchyBuilder builder = GenericDraweeHierarchyBuilder.newInstance(resources);
    builder.setPlaceholderImage(resources.getDrawable(drawable.shape_default_image));
    builder.setFailureImage(resources.getDrawable(drawable.shape_default_image));
    return builder.build();
}

Uri uri = Uri.parse(imgUrl);
ImageRequest request = ImageRequestBuilder.newBuilderWithSource(uri)
        .setResizeOptions(new ResizeOptions(50, 50))
        .build();
DraweeController controller = Fresco.newDraweeControllerBuilder()
        .setOldController(holder.photoIV.getController())
        .setImageRequest(request)
        .build();
photoIV.setController(controller);

//以下两个方法与其他网上不同，避免内存溢出
//判断是否缓存了图片，并进行加载（不做处理）
public void loadImage(Context context, String uri, ImageSize size, final ImageLoadingListener listener) {
    if (listener == null) {
        return;
    }

    if (TextUtils.isEmpty(uri)) {
        listener.onFailure();
        return;
    }

    ImageRequestBuilder builder = ImageRequestBuilder
            .newBuilderWithSource(Uri.parse(uri))
            .setProgressiveRenderingEnabled(false);
    if (size != null) {
        builder.setResizeOptions(new ResizeOptions(size.getWidth(), size.getHeight()));
    }

    ImageRequest imageRequest = builder.build();
    ImagePipeline imagePipeline = Fresco.getImagePipeline();
    final DataSource<CloseableReference<CloseableImage>>
            dataSource = imagePipeline.fetchDecodedImage(imageRequest, context);

    final DataSubscriber<CloseableReference<CloseableImage>> dataSubscriber = new
            BaseDataSubscriber<CloseableReference<CloseableImage>>() {
                @Override
                public void onNewResultImpl(
                        DataSource<CloseableReference<CloseableImage>> dataSource) {
                    if (!dataSource.isFinished()) {
                        return;
                    }
                    CloseableReference<CloseableImage> closeableReference = dataSource
                            .getResult();
                    if (closeableReference == null) {
                        return;
                    }
                    try {
                        Bitmap bitmap = null;
                        if (closeableReference.get() instanceof CloseableBitmap) {
                            CloseableBitmap closeableBitmap = (CloseableBitmap)
                                    closeableReference.get();
                            bitmap = closeableBitmap.getUnderlyingBitmap();
                        }

                        //Bitmap bitmap = closeableBitmap.getUnderlyingBitmap();
                        if (bitmap != null && !bitmap.isRecycled()) {
                            //Bitmap copybitmap =
                            SoftReference<Bitmap> copyBitmap = new SoftReference<Bitmap>(Bitmap.createBitmap(bitmap));
                            //  Bitmap copybitmap = ImageBlur.createRGBABitmap(bitmap, bitmap.getWidth(), bitmap.getHeight(),1);
                            listener.onSuccess(copyBitmap.get());
                        }
                    } finally {
                        closeableReference.close();
                        dataSource.close();
                    }
                }

                @Override
                public void onFailureImpl(DataSource dataSource) {
                    listener.onFailure();
                    dataSource.close();
                }
            };
    dataSource.subscribe(dataSubscriber, CallerThreadExecutor.getInstance());
}
//（做处理压缩重新设置宽高）模糊化需要
@Override
public void getImageThumbnail(Context context, String uri, ImageSize size, final ImageLoadingListener listener) {
    if (listener == null) {
        return;
    }

    if (TextUtils.isEmpty(uri)) {
        listener.onFailure();
        return;
    }

    ImageRequestBuilder builder = ImageRequestBuilder
            .newBuilderWithSource(Uri.parse(uri))
            .setProgressiveRenderingEnabled(false);
    if (size != null) {
        builder.setResizeOptions(new ResizeOptions(size.getWidth(), size.getHeight()));
    }

    ImageRequest imageRequest = builder.build();
    ImagePipeline imagePipeline = Fresco.getImagePipeline();
    final DataSource<CloseableReference<CloseableImage>>
            dataSource = imagePipeline.fetchDecodedImage(imageRequest, context);

    dataSource.subscribe(new BaseDataSubscriber<CloseableReference<CloseableImage>>() {
                             @Override
                             public void onNewResultImpl(
                                     DataSource<CloseableReference<CloseableImage>> dataSource) {
                                 if (!dataSource.isFinished()) {
                                     return;
                                 }
                                 CloseableReference<CloseableImage> closeableReference = dataSource
                                         .getResult();
                                 if (closeableReference != null) {
                                     try {
                                         Bitmap bitmap = null;
                                         if (closeableReference.get() instanceof CloseableBitmap) {
                                             CloseableBitmap closeableBitmap = (CloseableBitmap)
                                                     closeableReference.get();
                                             bitmap = closeableBitmap.getUnderlyingBitmap();
                                         }
                                         //Bitmap bitmap = closeableBitmap.getUnderlyingBitmap();
                                         if (bitmap != null && !bitmap.isRecycled()) {
                                             // Bitmap thumbbitmap = ThumbnailUtils.extractThumbnail(bitmap, 100, 100);
                                             SoftReference<Bitmap> copyBitmap = new SoftReference<Bitmap>(ImageUtil.createThumbnail(bitmap, 100, 100));
                                             listener.onSuccess(copyBitmap.get());
                                         }
                                     } finally {
                                         closeableReference.close();
                                         dataSource.close();
                                     }
                                 }
                             }

                             @Override
                             public void onFailureImpl(DataSource dataSource) {
                                 listener.onFailure();
                                 dataSource.close();
                             }
                         },
            CallerThreadExecutor.getInstance());
}
//回调接口
public interface ImageLoadingListener {
    void onSuccess(Bitmap var1);

    void onFailure();
}
//加载不做处理的
loadImage(context,imageView,null,new ImageLoadingListener() {
            @Override
            public void onSuccess(final Bitmap bitmap) {
//                ImageUtil.blurBitMap(bitmap, 10);
//                ad_cover.setImageBitmap(bitmap);
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        ad_cover.setImageBitmap(bitmap);
                    }
                });

            }

            @Override
            public void onFailure() {

            }
        });
//加载压缩过的（模糊化处理）
getImageThumbnail(context,imageView,null,new ImageLoadingListener() {
            @Override            
	    public void onSuccess(final Bitmap bitmap) {                
		blurBitMap(bitmap, 10);//模糊化处理（压缩后处理效率高）
//                ad_cover.setImageBitmap(bitmap);                
		handler.post(new Runnable() {                    
		@Override                    
		public void run() {                        
		ad_cover.setImageBitmap(bitmap);                    
		}                
		});            
		}            
		@Override            
		public void onFailure() {     
		       }        });