Best way to download images on Android

问题

I'm developing an Android application which uses several images and I would like transfer bigger images (2-6 MB) on a web server to download them when need.
I've never tried it before so I've found a method which uses AsyncTask to download images on button click, is this the best solution?

Any better options or opinions?


EDIT: I'm trying koush's ion

EDIT 2: I tried ion (https://github.com/koush/ion) and I like it here very well, very easy to use. advised

回答1:

   Use Universal image loader for downloading images asynchronously.  

  [https://github.com/nostra13/Android-Universal-Image-Loader][1].


  The Library itself has a sample code to download image.you may refer it..


  [1]: https://github.com/nostra13/Android-Universal-Image-Loader
After downloading library  add library with your project and insert the below code at necessary place


String final_url="www.google.com/.....";
ImageView image;

ImageLoader  imageloader = ImageLoader.getInstance();

imageloader.init(ImageLoaderConfiguration.createDefault(context));

DisplayImageOptions options; = new DisplayImageOptions.Builder()
                .showImageForEmptyUri(R.drawable.ic_empty)
                .showImageOnFail(R.drawable.ic_error)
                .resetViewBeforeLoading(true).cacheOnDisk(true)
                .imageScaleType(ImageScaleType.EXACTLY)
                .bitmapConfig(Bitmap.Config.RGB_565).considerExifParams(true)
                .cacheInMemory(true)
                .displayer(new FadeInBitmapDisplayer(300)).build();
imageloader.displayImage(final_url, image);

回答2:

Best practice: http://developer.android.com/training/displaying-bitmaps/index.html. Useful libraries: Picasso - http://square.github.io/picasso; Glide - github.com/bumptech/glide.

回答3:

I strongly recommend to use Glide or Picasso, which are the most used libraries nowadays. Just google "Glide for Android" or "Picasso for Android" and they take care of the threading, caching, optimization, etc. I hope it helps!

回答4:

Actually the most important reason to useAsyncTask is that you want a mechanism to do a lengthy operation with out blocking your UI. With it you also get rid of managing child thread and synchronization. And that's it. If you want other functionalities, such as bitmap caching, you will have to implement on your own or use some third-party tools.

回答5:

Use lazy loading images for this and use image caching.This is the best way to do it.

https://github.com/thest1/LazyList

http://androidexample.com/Download_Images_From_Web_And_Lazy_Load_In_ListView_-_Android_Example/index.php?view=article_discription&aid=112&aaid=134

http://sunil-android.blogspot.in/2013/09/lazy-loading-image-download-from.html

You can find some more examples for lazyloading.Hope the above links are also useful.

来源：https://stackoverflow.com/questions/25499868/best-way-to-download-images-on-android