Sebelumnya baca tutorial : LATIHAN FLUTTER WEEK#1 : COLUMN CLASS
Ubah bagian body menjadi
body: new Center( child: new Row( children: <Widget>[ Container( margin: EdgeInsets.all(5.0), width: 100.0,height: 100.0,color: Colors.orange, child: new Center(child: new Icon(Icons.camera,color: Colors.white,size: 80.0,),), ), Container( margin: EdgeInsets.all(5.0), width: 100.0,height: 100.0,color: Colors.blueAccent, child: new Center(child: new Icon(Icons.image,color: Colors.white,size: 80.0,),), ), Container( margin: EdgeInsets.all(5.0), width: 100.0,height: 100.0,color: Colors.redAccent, child: new Center(child: new Icon(Icons.favorite,color: Colors.white,size: 80.0,),), ) ], ) )
Semoga bermanfaat