Stack(

    alignment: Alignment.center,

    children: [

        Container(

        width: 160.0,

        height: 160.0,

        child: ClipRRect(

                borderRadius: BorderRadius.all(Radius.circular(16.0)),

                child: Image.asset('images/default_avatar.jpg'),

            ),

        ),

        Material(

        type: MaterialType.transparency,

        child: InkWell(

                borderRadius: BorderRadius.all(Radius.circular(16.0)),

                child: Container(

                    width: 160.0,

                    height: 160.0,

                    ),

                onTap: () {},

            ),

        ),

    ],

);