Flutter routing A—>B—>C

1. Conventional push, result and pop will not be described in detail

2. A—>B—>C, C directly returns to A after the operation is successful

Navigator.of(context)..pop()..pop(); 

chain programming, 
such as: _listDate..addAll(datas)..addAll(datas); equivalent to 
_listDate.addAll(datas); 
_listDate.addAll( datas);