How to prevent this? Is there a better method for downloading images that is also faster? Improve this question. Adam Johns To make the object null , we can assign it null i. You can catch out of memory in Android Here is the wonderful example to convert images to bitmap and list them in gridview, listview and in pager.
Check this out github. Add a comment. Active Oldest Votes. Improve this answer. Piyush Piyush Great library. I struggled a little trying to get it to work in a listview just by reading the instructions, but after downloading their sample project and modeling my usage after theirs, it works flawlessly. Note that since , development at least from the original author has stopped.
It would help if you always mention class names and project names. Notice that those links go to landing pages that give you no idea of the project? Roger Roger 2 2 silver badges 6 6 bronze badges.
Kindle Q 2 2 gold badges 16 16 silver badges 27 27 bronze badges. Ankit Singh Ankit Singh 3 3 silver badges 14 14 bronze badges. Add following lines of code at the top of tag of AndroidManifest.
Prateek Jain Prateek Jain 73 1 1 silver badge 5 5 bronze badges. Max Base 1 1 gold badge 6 6 silver badges 15 15 bronze badges. John smith John smith 1, 15 15 silver badges 27 27 bronze badges. Please advice me how memoryCache is used. I am new. VishnuPrabhu you can use Glide that is much easier way to show images and some of feature are very new in that: github.
FranciscoBouza 6 6 silver badges 18 18 bronze badges. Options ; options. Zubair Ahmed Zubair Ahmed 2, 2 2 gold badges 25 25 silver badges 47 47 bronze badges. I recommend using the altex-image-downloader library, which makes it easy to download images: AltexImageDownloader.
Expert Suggestion Expert Suggestion 5 5 silver badges 16 16 bronze badges. Shahzad Afridi Shahzad Afridi 1, 20 20 silver badges 22 22 bronze badges. Christopher Mills Christopher Mills 9 9 silver badges 23 23 bronze badges. Pramesh Bhalala Pramesh Bhalala 1 1 gold badge 2 2 silver badges 8 8 bronze badges.
Please consider explaining how the code helps to solve OP's issue instead of spoonfeeding code. Request uri ; request. Ali shahid Ali shahid 1 1 1 bronze badge. JPEG, , fos fos. Kishan Mevada Kishan Mevada 27 4 4 bronze badges. The Overflow Blog.
You can view the complete source code or download the project on GitHub. 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. Let's start with an own implementation you can find the code at the end of the post. First of all, this is a Basic ImageDownloader and that's it.
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. The advantage of this approach - it is simple and you have a clear overview of what's going on. Note: in case of large images, you might need to scale them down. Android DownloadManager is a way to let the system handle the download for you. It's actually capable of downloading any kind of files, not just images.
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. You can also register a BroadcastReceiver to get notified after you download is complete. The setup is pretty much straightforward, refer to the linked project for sample code.
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. Now the introduction of the great stuff - the libraries.
I will start with Volley , a powerful library created by Google and covered by the official documentation. While being a general-purpose networking library not specializing on images, Volley features quite a powerful API for managing images. You will need to implement a Singleton class for managing Volley requests and you are good to go. You might want to replace your ImageView with Volley's NetworkImageView , so the download basically becomes a one-liner:.
If you need more control, this is what it looks like to create an ImageRequest with Volley:. It is worth mentioning that Volley features an excellent error handling mechanism by providing the VolleyError class that helps you to determine the exact cause of an error.
If your app does a lot of networking and managing images isn't its main purpose, then Volley it a perfect fit for you. Square's Picasso is a well-known library which will do all of the image loading stuff for you.
Just displaying an image using Picasso is as simple as:. For more control you can implement the Target interface and use it to load your image into - this will provide callbacks similar to the Volley example. Check the demo project for examples. Picasso also lets you apply transformations to the downloaded image and there are even other libraries around that extend those API.
Universal Image Loader is an another very popular library serving the purpose of image management. It uses its own ImageLoader that once initialized has a global instance which can be used to download images in a single line of code:.
The opts argument in this example is a DisplayImageOptions object. Refer to the demo project to learn more. Note : the author has mentioned that he is no longer maintaining the project as of Nov 27th, But since there are many contributors, we can hope that the Universal Image Loader will live on. Facebook's Fresco is the newest and IMO the most advanced library that takes image management to a new level: from keeping Bitmaps off the java heap prior to Lollipop to supporting animated formats and progressive JPEG streaming.
To learn more about ideas and techniques behind Fresco, refer to this post. The basic usage is quite simple. Note that you'll need to call Fresco. Initializing Fresco more than once may lead to unpredictable behavior and OOM errors. Fresco uses Drawee s to display images, you can think of them as of ImageView s:.
As you can see, a lot of stuff including transformation options gets already defined in XML, so all you need to do to display an image is a one-liner:. Fresco provides an extended customization API, which, under circumstances, can be quite complex and requires the user to read the docs carefully yes, sometimes you need to RTFM.
Note that the following text reflects my personal opinion and should not be taken as a postulate. In case you missed that, the Github link for the demo project. I have just came from solving this problem on and I would like to share the complete code that can download, save to the sdcard and hide the filename and retrieve the images and finally it checks if the image is already there.
The url comes from the database so the filename can be uniquely easily using id. Why do you really need your own code to download it? How about just passing your URI to Download manager? I have a simple solution which is working perfectly. The code is not mine, I found it on this link. Here are the steps to follow:. It needs a context, better to use the pass in the application context by getApplicationContext.
This method can be dumped into your Activity class or other util classes. This private class need to be placed in your Activity class as a subclass. After the image is downloaded, in the onPostExecute method, it calls the saveImage method defined above to save the image.
The AsyncTask for downloading the image is defined, but we need to execute it in order to run that AsyncTask. To do so, write this line in your onCreate method in your Activity class, or in an onClick method of a button or other places you see fit. IMO this solves the issue! If you want further steps such as load the image you can follow these extra steps:.
After the image is downloaded, we need a way to load the image bitmap from the internal storage, so we can use it. This method takes two paramethers, a context and an image file name, without the full path, the context.
Now we have everything we needed for setting the image of an ImageView or any other Views that you like to use the image on. Droidman post is pretty comprehensive. Volley works good with small data of few kbytes. When I tried to use the 'BasicImageDownloader. I used Volley in another test app and that kept crashing because of leaks so I am worried about using Volley for the image downloader images can be few kB. I used Picasso and it worked well, there is small change probably an update on Picasso from what is posted above.
Below code worked for me:. As Google tells, for now, don't forget to add also readable on external storage in the manifest :. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow.
Learn more. How to download and save an image in Android Ask Question. Asked 8 years, 8 months ago. Active 2 months ago. Viewed k times. How do you download and save an image from a given url in Android?
Improve this question. Lance Roberts Droidman Droidman Add a comment. Active Oldest Votes. Edit as of Just displaying an image using Picasso is as simple as: Picasso. It uses its own ImageLoader that once initialized has a global instance which can be used to download images in a single line of code: ImageLoader. I have included examples for progressive JPEG's and animated images into the sample project.
Conclusion - "I have learned about the great stuff, what should I use now? If your app saves images or other files as a result of a user or an automated action and you don't need the images to be displayed often, use the Android DownloadManager. And here's the BasicImageDownloader. Bitmap; import android.
0コメント