android - ImageView with setBackgroundResource and setImageBitmap -

I have an image view that I'm making it dynamic, now I

  set imageView I am doing SetImageBitmap (bitmap); ImageView.setBackgroundResource (R.drawable.a);   
 setBackgroundResource is dragging the image, because bitmap size increases.  
 Why is that so? Is there any remedy?   
 
 
 A background resource is designed to fill the entire scene, which is why the content of the scene Has increased in size.  
 A possible solution would be to use 9-patch drawables, which is only assigned by you.  
 Alternatively, your background needs to be scaled to normal view content increase, and reset it to a new background.