使用SharedPreferences设置登录状态并在应用启动时进行检索-Flutter

您可以使用FutureBuilder解决此问题。

@overrideWidget build(BuildContext context) { new FutureBuilder<String>(    future: getLoginState(),    builder: (BuildContext context, AsyncSnapshot<String> snapshot) {      switch (snapshot.connectionState) {        case ConnectionState.active:        case ConnectionState.waiting:          return new Text('Loading...');        case ConnectionState.done:          if (snapshot.hasData) { loginState = snapshot.data; if(loginState) {  return Container(child: Text('Logged In')); } else {  return Container(child: Text('Not Logged In)); }          } else {return  Container(child: Text('Error..));          }      }    },  ) }

注意：我们不需要

isLoggedIn