颤振保持闪屏3秒钟。如何在Flutter中实现启动屏幕？

您可以使用延迟执行代码

Future.delayed

new Future.delayed(const Duration(seconds: 3), () {  Navigator.pushNamed(context, '/login');});

更新

const delay = 3;widget.countdown = delay;StreamSubscription sub;sub = new Stream.periodic(const Duration(seconds: 1), (count) {  setState(() => widget.countdown--);    if(widget.countdown <= 0) {    sub.cancel();    Navigator.pushNamed(context, '/login');  }});