title: back button inside AppBar showing black screen in flutter
body: <p>I have bottom tab navigator that contains of A and B screens, inside B screen I have widget that navigate to C page and inside C page I want to add back arrow to go back to previous screen (B screen), so...
  I have simple widget that the code looks like this</p>
  
  <pre><code>@override
    Widget build(BuildContext context) {
      return SafeArea(
          child: Scaffold(
              resizeToAvoidBottomPadding: false,
              appBar: AppBar(
                leading: IconButton(
                  icon: Icon(Icons.arrow_back),
                  onPressed: () =&gt; Navigator.of(context).pop(),
                ),
                title: Text("XXX"),
                centerTitle: true,
              ),
              body: detail()));
    }
  </code></pre>
  
  <p>the problem is whenever I click back arrow.. it turns to black screen... I don't get any idea what the problem is... so is there a way to go to my previous screen?
  and this is how I ndo navigate from B screen to C page</p>
  
  <pre><code>InkWell(
                        onTap: () {Navigator.of(context).pushReplacement(MaterialPageRoute(
                              builder: (context) =&gt; new NextScreen(check: values)));
                        },
                        child: Text(
                          "Next...",
                          style: TextStyle(
                            fontSize: 13.0,
                          ),
                        ),
                      )
  </code></pre>