title: How to download and save image into the app directory using Ion library
body: <p>I am using the Ion library, and its working well. But on the other Hand I have to download image and save it to app directory. </p>
  
  <p>What I am trying to do is , using a Image view in the navigation view header and  want to download image one time and to show that image for the next time until and Unless I discharge it</p>
  
  <p>So I as I am using the Ion library to make calls to server , SO I am thinking to Why not use Ion library for this purpose too. All I know that it has a valid function for downloading image and to show it in image view like that </p>
  
  <pre><code> // This is the "long" way to do build an ImageView request... it allows you to set headers, etc.
  Ion.with(context)
  .load("http://example.com/image.png")
  .withBitmap()
  .placeholder(R.drawable.placeholder_image)
  .error(R.drawable.error_image)
  .animateLoad(spinAnimation)
  .animateIn(fadeInAnimation)
  .intoImageView(imageView);
  
  // but for brevity, use the ImageView specific builder...
  Ion.with(imageView)
  .placeholder(R.drawable.placeholder_image)
  .error(R.drawable.error_image)
  .animateLoad(spinAnimation)
  .animateIn(fadeInAnimation)
  .load("http://example.com/image.png");
  </code></pre>
  
  <p>I really do not know how to use it and save the image in the app directory rather then showing it directly in the Image view. </p>
  
  <p>I want to download image and save image in the app directory. Can I use Ion library for this purpose or I have to do something more. ?? Please help. </p>