Expanded
A widget that expands a child of a Row, Column, or Flex so that the child fills the available space.
Example
Center( child: Column( children: <Widget>[ Container( color: Colors.red, height: 100, width: 100, ), Expanded( child: Container( color: Colors.blue, width: 100, ), ), Container( color: Colors.red, height: 100, width: 100, ), ], ), )