flutter 线性布局，填充

       Row(             mainAxisAlignment: MainAxisAlignment.spaceBetween,             children: [               Expanded(/个很关键                 child: Container(                   alignment: Alignment.center,//这是填充                   child: const Text(                     " ",                     style: TextStyle(fontSize: 18),                   ),                 ),               ),               Expanded(/个很关键                 child: Container(                   margin: const EdgeInsets.only(left: 16, top: 15),                   alignment: Alignment.center,//这是填充                   child: const Text(                     "扔一个",                     style: TextStyle(                         fontSize: 16,                         color: Color(0xFF1A1A1A),                         fontWeight: FontWeight.w500),                   ),                 ),               ),               Expanded(/个很关键                   child: GestureDetector(                 onTap: () { 
                          MyRouter.pushMy(context, BottleRule());
                },
                child: Container(
                  alignment: Alignment.centerRight,//这个是填满
                  margin: EdgeInsets.only(top: 15),
                  child: Container(
                    margin: EdgeInsets.only(right: 16),
                    child: const Image(
                      image: AssetImage(
                          'assets/images/icon_drift_instrution_black.png'),
                      width: 24,
                      height: 24,
                    ),
                  ),
                ),
              )),
            ],
          ),