So far whenever I needed to use a conditional statement within a Widget I have done the following (Using Center and Containers as simplified dummy examples):
I personally use if/else statement in children with this kind of block statement. It only supports on Dart version 2.3.0 above.
if / else
Column(
children: [
if (_selectedIndex == 0) ...[
DayScreen(),
] else ...[
StatsScreen(),
],
],
),
if / else if
Column(
children: [
if (_selectedIndex == 0) ...[
DayScreen(),
] else if(_selectedIndex == 1)...[
StatsScreen(),
],
],
),