Answers for "add button in flutter"

flutter raisedbutton example

RaisedButton(child: Text("Rock & Roll"),
                onPressed: _changeText,
                color: Colors.red,
                textColor: Colors.yellow,
                padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
                splashColor: Colors.grey,
              )

flutter button

FlatButton(
              color: Colors.red,
              splashColor: Colors.black12,
              onPressed: (){
              },
              child: Text(
                "Nouvelle Texte"
              ),
            ),