![]() ![]() They can do much more than just downloading and displaying images, including: creating and managing the memory/disk cache, resizing images, transforming them and more. Now the introduction of the great stuff - the libraries. The DownloadManager also does not provide any API for you app to track the download progress. Using the DownloadManager is generally not a good idea if you also want to display the image, since you'd need to read and decode the saved file instead of just setting the downloaded Bitmap into an ImageView. The setup is pretty much straightforward, refer to the linked project for sample code. You can also register a BroadcastReceiver to get notified after you download is complete. You may let your download happen silently and invisible to the user, or you can enable the user to see the download in the notification area. It's actually capable of downloading any kind of files, not just images. Note: in case of large images, you might need to scale themĪndroid DownloadManager is a way to let the system handle the download for you. A good way to go if all you need is downloading/displaying and saving some images, whilst you don't care about maintaining a memory/disk cache. The advantage of this approach - it is simple and you have a clear overview of what's going on. All it does is connecting to the given url, reading the data and trying to decode it as a Bitmap, triggering the OnImageLoaderListener interface callbacks when appropriate. First of all, this is a BasicImageDownloader and that's it. Let's start with an own implementation (you can find the code at the end of the post). In my conclusion at the end of this post I will share my humble opinion about the proper use-case for each particular way of image downloading I've mentioned. Note: I have not adjusted the permission management for SDK 23+ (Marshmallow) yet, thus the project is targeting SDK 22 (Lollipop). You can view the complete source code or download the project on GitHub. I've created a demo project named "Image Downloader" that demonstrates how to download (and save) an image using my own downloader implementation, the Android's built-in DownloadManager as well as some popular open-source libraries. Since this post has received quite a lot of attention, I have decided to completely rework it to prevent the folks from using deprecated technologies, bad programming practices or just doing silly things - like looking for "hacks" to run network on the main thread or accept all SSL certs. Note: though the BasicImageDownloader handles possible errorsĪnd will prevent your app from crashing in case anything goes wrong, it will not performĪny post-processing (e.g. Into your project, implement the OnImageLoaderListener interface Skip to the bottom of this post, copy the BasicImageDownloader (javadoc version here) Edit as of - The Ultimate Guide to image downloading ![]()
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