Load images from disk cache with Picasso if offlin

2019-01-07 13:30发布

I have some images that I download from different web sites when the app starts, by doing this:

Picasso.with(context).load(image_url).fetch();

Now, suppose the user closes the app and turns offline. When the app starts again, Picasso display the images in this way:

Picasso.with(ctx).load(image_url).placeholder(R.drawable.ph).into(imageView);

The problem is that some images are loaded from the disk cache (yellow triangle in debug mode), and for the others Picasso shows the placeholder.

Why? I'm expecting that every image is loaded from the disk cache.

5条回答
干净又极端
2楼-- · 2019-01-07 14:13

To avoid creating of separate instance of RequestCreator like here , do this:

 RequestCreator request = mPicasso.load(TextUtils.isEmpty(imageUrl) ? null : imageUrl)
                    .placeholder(R.drawable.ic_default)
                    .error(R.drawable.ic_default)
                    .transform(transformations)
                    .noFade()
                    .centerCrop();
            request
                    .networkPolicy(NetworkPolicy.OFFLINE)
                    .into(mImageView, new Callback.EmptyCallback(){
                        @Override
                        public void onError() {
                            super.onError();
                            request.into(mImageView);
                        }
                    });
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唯我独甜
3楼-- · 2019-01-07 14:15

You can use this code by this strategy Picasso will look for images in cache and if it failed only then image will be downloaded over network.

 Picasso.with(context)
                    .load(Uri.parse(getItem(position).getStoryBigThumbUrl()))
                    .networkPolicy(NetworkPolicy.OFFLINE)
                    .into(holder.storyBigThumb, new Callback() {
                        @Override
                        public void onSuccess() {

                        }

                        @Override
                        public void onError() {
                            // Try again online if cache failed
                            Picasso.with(context)
                                    .load(Uri.parse(getItem(position)
                                            .getStoryBigThumbUrl()))
                            .placeholder(R.drawable.user_placeholder)
                            .error(R.drawable.user_placeholder_error)
                                    .into(holder.storyBigThumb);
                        }
                    });
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别忘想泡老子
4楼-- · 2019-01-07 14:22

Do this:

Picasso.with(this)
            .load(url)
            .networkPolicy(NetworkPolicy.OFFLINE)
            .into(imageView);

Also check my previous answer, maybe will help you: Invalidate cache in Picasso

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Juvenile、少年°
5楼-- · 2019-01-07 14:31

This logic worked for me:

if network is available:
    Picasso.with(context).load(image).into(imageView);
else:
    Picasso.with(context).load(image).networkPolicy(NetworkPolicy.OFFLINE).into(imageView);
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欢心
6楼-- · 2019-01-07 14:32

Is OkHttp and Okio present on the class path? (or in your dependencies) Because by default Picasso lets the HttpClient handle the caching (it does not do this by default)

You have 2 options

  • include the mentioned dependencies (recommended)
  • specify the cache manually
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