flutter rounded container white stripes code example

Example 1: flutter container radius

Container(
  child: Text("It's text..."),
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(10),  // radius of 10
    color: Colors.green  // green as background color
  )
)

Example 2: flutter rounded container transperent corners

new Container(
          height: 300.0,
          color: Colors.transparent,
          child: new Container(
            decoration: new BoxDecoration(
              color: Colors.green,
              borderRadius: new BorderRadius.only(
                topLeft: const Radius.circular(40.0),
                topRight: const Radius.circular(40.0),
              )
            ),
            child: new Center(
            child: new Text("Hi modal sheet"),
           )
         ),
        ),