borderRadius property
If non-null, the corners of this box are rounded by this BorderRadius.
Applies only to boxes with rectangular shapes; ignored if shape is not BoxShape.rectangle.
The shape or the borderRadius won't clip the children of the decorated Container.
If the clip is required, insert a clip widget (e.g., ClipRect, ClipRRect, ClipPath) as the child of the Container.
Be aware that clipping may be costly in terms of performance.
Implementation
final BorderRadiusGeometry borderRadius;