flutter button with border code example

Example 1: flat button rounded shape

new OutlineButton(
  child: new Text("Button text"),
  onPressed: null,
  shape: new RoundedRectangleBorder(borderRadius: new BorderRadius.circular(30.0))
)

Example 2: flutter button border radius

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