执行 Navigator.pop 时出现黑屏。我尝试了其他链接但没有得到解决方案答案

【问题标题】：Getting black screen when doing Navigator.pop. I have tried other links but not getting the solution执行 Navigator.pop 时出现黑屏。我尝试了其他链接但没有得到解决方案
【发布时间】：2020-01-07 07:50:07
【问题描述】：

I am getting black screen when hitting Navigator.pop

https://stackoverflow.com/questions/53723294/flutter-navigator-popcontext-returning-a-black-screen/54146583


// Main Code

        void main() => runApp(MaterialApp(

              theme: ThemeData(
                  primaryColor: Color(0xfffea502), accentColor: Colors.blueAccent),
              debugShowCheckedModeBanner: false,
              home: SplashScreen(),
            ));

// 子类

        class SplashScreen extends StatefulWidget {
          @override
          _SplashScreenState createState() => _SplashScreenState();
        }

        class _SplashScreenState extends State<SplashScreen> {

          var prefs = null;

          BuildContext mContext;

          Future<void> _addSharedPreference() async {
            prefs = await SharedPreferences.getInstance();
          }

          @override
          void initState() {
            // TODO: implement initState
            super.initState();



            _addSharedPreference();

            Timer(Duration(seconds: 3), () {
              var memberId = prefs.getString(SupportableConstant.MEMBERID_Pref);


              if (memberId == null || memberId == "0") {

    // Going to other activity

                Navigator.pop(mContext);
                Navigator.push(
                  mContext,
                  MaterialPageRoute(builder: (context) => LoginScreen()),
                );
              } else {

    // Going to other activity

        enter code here
                Navigator.pop(mContext);
                Navigator.push(
                  mContext,
                  MaterialPageRoute(builder: (context) => BottomNavigationScreen()),
                );
              }
            });
          }

这是 main.dart 代码。这里我使用了 MaterialApp 来进一步运行应用程序。

当我要进行其他活动时，它工作正常，但如果我从任何活动上方按后退按钮，则它会显示黑屏。

我尝试了一些解决方案，但都不起作用。

【问题讨论】：

标签： flutter

【解决方案1】：

If you want your code to execute after the future function has been executed. Then put .then() after the function call. i.e  functionName().then(); 
 _addSharedPreference().then((_){
        var memberId = prefs.getString(SupportableConstant.MEMBERID_Pref);

                Navigator.pushReplacement(
                  mContext,
                  MaterialPageRoute(builder: (context) => LoginScreen()),
                );
    });

【讨论】：

没有。我的活动正确重定向但是当我关闭所有其他活动时，最后我得到了黑屏

【解决方案2】：

 class SplashScreen extends StatefulWidget {
      @override
      _SplashScreenState createState() => _SplashScreenState();
    }

    class _SplashScreenState extends State<SplashScreen> {

      var prefs = null;

      BuildContext mContext;

      Future<void> _addSharedPreference() async {
        prefs = await SharedPreferences.getInstance();
      }

      @override
      void initState() {
        // TODO: implement initState
        super.initState();



        _addSharedPreference();

        Timer(Duration(seconds: 3), () {
          var memberId = prefs.getString(SupportableConstant.MEMBERID_Pref);


          if (memberId == null || memberId == "0") {

// Going to other activity


            Navigator.pushReplacement(
              mContext,
              MaterialPageRoute(builder: (context) => LoginScreen()),
            );
          } else {

// Going to other activity



            Navigator.pushReplacement(
              mContext,
              MaterialPageRoute(builder: (context) => BottomNavigationScreen()),
            );

或

Navigator.of(context).pushReplacement(MaterialPageRoute(
        builder: (BuildContext context) => BottomNavigationScreen()));
          }
        });
      }

【讨论】：