show method
Implementation
void show(BuildContext context, {bool dismissCurrent = true}) {
final messenger = ScaffoldMessenger.maybeOf(context);
if (messenger == null) return;
if (dismissCurrent) messenger.removeCurrentMaterialBanner();
final banner = build(
context,
onClose: actions == null
? () => messenger.hideCurrentMaterialBanner(reason: MaterialBannerClosedReason.dismiss)
: null,
onCancel: messenger.hideCurrentMaterialBanner,
);
messenger.showMaterialBanner(banner);
}