This post will introduce some ways to make a widget center horizontally and vertically within a screen.
Use Center widget
Center is a widget that make its child center-aligned within itself. Center widget will be as big as possible if its dimensions are constrained and
heightFactor are null
Scaffold( appBar: AppBar( title: Text('Home'), ), backgroundColor: Colors.white, body: SafeArea( child: Center(child: Text('Centered text')), ), );
Align widget aligns its child within itself and optionally sizes itself based on the child’s size. Its
alignment determine how to align its child.
alignment: Alignment.center makes its child align center vertically and horizontally.
Container( width: double.infinity, height: double.infinity, child: Align( alignment: Alignment.center, child: FlutterLogo( size: 120, ), ), )
Column widget displays its children in a vertical array. It has 2 properties which help align its children, which are
crossAxisAlignment. The former one determines how its children should be placed along the main axis, the later uses cross axis.
If we wrap a Column within a Container with max width and height, we can set Column’s children to center aligned by applying
mainAxisAlignment: MainAxisAlignment.center and
Container( width: double.infinity, height: double.infinity, child: Column( mainAxisAlignment: MainAxisAlignment.center, crossAxisAlignment: CrossAxisAlignment.center, children: [ Container( width: 100, height: 100, color: Colors.blueAccent, ) ], ), )
Row displays its children in a horizontal array. We can apply Row widget to solve this problem like we apply Column, but only need
mainAxisAlignment: MainAxisAlignment.center property.
Container( width: double.infinity, height: double.infinity, child: Row( mainAxisAlignment: MainAxisAlignment.center, children: [ Container( width: 100, height: 100, color: Colors.orange, ) ], ), )