Android: .png to Imageview? Most efficent way?

I've got a .png file in my D开发者_如何学编程rawable folder. How do I make it into an Imageview?

imageView.setImageResource(R.drawable.your_drawable);

<ImageView
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:src="@drawable/my_image"
/>