Flutter add shadow effects

Container(
                  width: double.infinity,
                  height: ScreenUtil.getInstance().setHeight(500),
                  decoration: BoxDecoration(
                      color: Colors.white,
                      borderRadius: BorderRadius.circular(8.0),
                      boxShadow: [
                        BoxShadow(
                            color: Colors.black12,
                            offset: Offset (0.0, 15.0), // xy-offset shadow
                            blurRadius: 15.0, // shadow blur
                            spreadRadius: 1.0 // shadow diffusion degree
                            )
                      ]),
                )