RaisedButton' is deprecated and shouldn't be used.
FlatButton, RaisedButton, and OutlineButton have been replaced by TextButton, ElevatedButton, and OutlinedButton respectively. ButtonTheme has been replaced by TextButtonTheme, ElevatedButtonTheme, and OutlinedButtonTheme. The original classes will be deprecated soon, please migrate code that uses them. There's a detailed migration guide for the new button and button theme classes in flutter. dev/go/material-button-migration-guide. refrence: https://api.flutter.dev/flutter/material/RaisedButton-class.html