flutter button border radius

    
        RaisedButton(
                onPressed: () {},
                color: Colors.amber,
                shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(10)),
                child: Text("Click This"),
              )
    

ElevatedButton(
  onPressed: () {},
  style: ElevatedButton.styleFrom(
  	shape: new RoundedRectangleBorder(
    	borderRadius: new BorderRadius.circular(30.0),
  	),
  ),
  child: Text(
    "Click ME!!"
  ),
)

OutlinedButton(
  child: Text('Woolha.com'),
  style: OutlinedButton.styleFrom(
    primary: Colors.white,
    backgroundColor: Colors.teal,
    shape: const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(10))),
  ),
)

shape: RoundedRectangleBorder(
  borderRadius: BorderRadius.circular(18.0),
  side: BorderSide(color: Colors.red)
),

style: ButtonStyle(
  shape: MaterialStateProperty.all<RoundedRectangleBorder>(
    RoundedRectangleBorder(
      borderRadius: BorderRadius.circular(18.0),
      side: BorderSide(color: Colors.red)
    )
  )
)

FlatButton(
              color: Colors.red,
              shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(18.0)),
              child: new Text('round button'),
              onPressed: () {},
            ),