title: Lazy loading in android
body: <p>I want to lazy load thumbnails of images that i receive via bluetooth in to a ListView . I saw many implementation of LazyLoading in android, but i just could not understand the flow how the lazy loader was working. </p>
  
  <p>Btw I referred to this site</p>
  
  <p><a href="http://androidexample.com/Download_Images_From_Web_And_Lazy_Load_In_ListView_-_Android_Example/index.php?view=article_discription&amp;aid=112&amp;aaid=134" rel="nofollow">http://androidexample.com/Download_Images_From_Web_And_Lazy_Load_In_ListView_-_Android_Example/index.php?view=article_discription&amp;aid=112&amp;aaid=134</a></p>
  
  <p>In the above implementation they use both Memory cache as well as File cache (In the class ImageLoader). I can't get why is it necessary to maintain two cache?<br>
  And in the same class he maintains a Map imageViews. Why would he need a mapping of imageViews and Image url? .</p>
  
  <p>Can anyone explain the flow of the above code or give some tips on designing my own lazyloader class.</p>
  
  <p>Thanks in advance </p>