Container(
                  width: double.infinity,
                  height: 100,
                  decoration: BoxDecoration(
                      color: Colors.white,
                      borderRadius: BorderRadius.circular(8.0),
                      boxShadow: [
                        BoxShadow(
                            color: Colors.black12,
                            offset: Offset(0.0, 15.0), //阴影xy轴偏移量
                            blurRadius: 15.0, //阴影模糊程度
                            spreadRadius: 1.0 //阴影扩散程度
                            )
                      ]),
                )