I always used Picasso Library for images. It's very useful for managing images and no worry about Memory problem. When I' download images from server or json , I used. And i store that image url to Database or somewhere. Now we can use that image in anywhere offline also. You should use an image loader library like Picasso, Volley or Universal Image Loader because they do the following things that your code doesn't do:.
By the way, you must never perform network requests on the UI thread and since HoneyComb, Android doesn't let you do it. If you will use the core method of loading image from network then it would take larger amount of code. But if we will use a 3rd party library like picasso then we will achieve our goal in few lines of code.
And Picasso Library is the best and simplest I found so far. We only need to write the following to load an image from internet using picasso. But if we will not use picasso library or any other library we may need to do it using AsyncTask that will require more lines of code. Source: Picasso Android Tutorial. Picasso automatically handles all pitfalls associated with image downloading such as caching downloaded image, look up cache, cancelling existing request, performing image transormations and decoding, resizing and cropping of images.
And it allows you to customize it, you can configure memory for cache, add request transformer used for adding global information to every request, add bitmap config to handle decoding images for format not covered by default bitmap config. It allows you to specify memory policy and network policy which makes it to use either cache or to download from the network.
It allows you to add placeholder and error images to be used while downloading and in case of error in downloading respectively. Here is the code using latest version 2. 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. Why use Android Picasso library to download images? Ask Question. Asked 7 years, 8 months ago.
Active 3 years, 8 months ago. In the first line, we are getting the ImageView instance from the layout. Java import androidx. AppCompatActivity; import android. Bundle; import android. ImageView; import com. More Functionalities of the Picasso Library For any real-time application, we must think of all possible cases. In the above code, we just download the image from the server link.
But how to display that image in the app. How to resize it and what if the image loading failed? We need to have another image showing an error message that image loading failed. This all matters for an app developer. The following code changes are made in the MainActivity. The placeholder image is shown immediately and replaced by the remote image when Picasso has finished fetching it.
Oct 24, Aug 17, Prepare version e. Mar 7, Remove references to building with maven. Jul 12, Initial commit. Feb 16, Aug 24, Update build. Fix checkstyle issue. Mar 5, Update links to Javadoc. If you experience errors loading images, you can attach a listener to the Builder object to print the stack trace.
If we wish to readjust the ImageView size after the image has been retrieved, we first define a Target object that governs how the Bitmap is handled:. Note: The Target object must be stored as a member field or method and cannot be an anonymous class otherwise this won't work as expected. The reason is that Picasso accepts this parameter as a weak memory reference. Because anonymous classes are eligible for garbage collection when there are no more references, the network request to fetch the image may finish after this anonymous class has already been reclaimed.
See this Stack Overflow discussion for more details. In other words, you are not allowed to do Picasso. We can use this custom Target approach to create a staggered image view using RecyclerView. We can then set the ratio before the image has loaded if we already know the height:width ratio using onBindViewHolder as shown below:.
Alternatively, we can set the ratio after the bitmap has loaded if we don't know that ratio ahead of time. To avoid using an anonymous class, we will implement the Target interface on the ViewHolder class itself for RecyclerView. When the callback is fired, we will calculate and update the image aspect ratio:.
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