Change the length of the appBar flutter code example
Example 1: height appbar flutter
appBar: PreferredSize(
preferredSize: Size.fromHeight(100.0),
child: AppBar(
automaticallyImplyLeading: false, // hides leading widget
flexibleSpace: SomeWidget(),
)
),
Example 2: get appbar size flutter
var height = AppBar().preferredSize.height;