I'm practising this code

CodePudding user response：

https://api.flutter.dev/flutter/widgets/StatefulWidget/createState.html

Change this,

 class HomePage extends StatefulWidget{
              @override
                _HomePageState createSatate ()=> _HomePageState(); // change createSatate to createState
              }

To,

 class HomePage extends StatefulWidget{
              @override
                _HomePageState createState ()=> _HomePageState();
              }

CodePudding user response：

class HomePage extends StatefulWidget{
  @override
  _HomePageState createSatate ()=> _HomePageState();
}

It's because of a typo.

Change createSatate to createState.

Your Homepage class will look like

class HomePage extends StatefulWidget{
  @override
  _HomePageState createState ()=> _HomePageState();
}