Flutter Layout Container Margin

You can use left and right values :)

@override
Widget build(BuildContext context) {
  return Scaffold(
    backgroundColor: Colors.white,
    body: Container(
      margin: const EdgeInsets.only(left: 20.0, right: 20.0),
      child: Container(),
    ),
  );
}

You can try: To the margin of any one edge

new Container(
    margin: const EdgeInsets.only(left: 20.0, right: 20.0),
    child: new Container()
)

You can try :To the margin of any all edge

new Container(
    margin: const EdgeInsets.all(20.0),
    child: new Container()
)

If you need the current system padding or view insets in the context of a widget, consider using [MediaQuery.of] to obtain these values rather than using the value from [dart:ui.window], so that you get notified of changes.

new Container(
    margin: EdgeInsets.fromWindowPadding(padding, devicePixelRatio),
    child: new Container()
)