The BoxDecoration class provides a variety of ways to draw a box. The box has a border, a body, and may cast a boxShadow. The shape of the box can be a circle or a rectangle. If it is a rectangle, then the borderRadius property controls the roundness of the corners. The following applies a BoxDecoration to a Container widget to draw an image of an owl with a thick black border and rounded corners.
color: const Color(0xff7c94b6),
image: const DecorationImage(
fit: BoxFit.cover, ),
border: Border.all( color: Colors.black, width: 8, ),
borderRadius: BorderRadius.circular(12), ), )