appbar.dart

TabController tabController;
@override
  void initState() {
    // TODO: implement initState
    super.initState();
    tabController = TabController(vsync: this, length: 2);
  }
AppBar(
        title: loader
            ? Shimmer.fromColors(
                child: Row(
                  crossAxisAlignment: CrossAxisAlignment.center,
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: <Widget>[
                    CircleAvatar(
                        // backgroundImage:
                        //     NetworkImage(auth.userdata[0].userimage),
                        ),
                    SizedBox(
                      width: 10,
                    ),
                    Text(
                      'Username',
                      style: TextStyle(
                          color: Colors.white,
                          fontSize: 22.0,
                          fontWeight: FontWeight.w600),
                    )
                  ],
                ),
                baseColor: Colors.grey,
                highlightColor: Colors.black)
            : Consumer<Auth>(
                builder: (ctx, auth, _) => GestureDetector(
                  onTap: () {
                    showDialog(
                      context: context,
                      builder: (BuildContext context) => CustomDialog(
                        username: auth.userdata[0].username,
                      ),
                    );
                  },
                  child: Container(
                      // color: Colors.red,
                      alignment: Alignment.center,
                      child: Row(
                        crossAxisAlignment: CrossAxisAlignment.center,
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: <Widget>[
                          CircleAvatar(
                            backgroundImage:
                                NetworkImage(auth.userdata[0].userimage),
                          ),
                          SizedBox(
                            width: 10,
                          ),
                          Text(
                            auth.userdata[0].username,
                            style: TextStyle(
                                color: Colors.white,
                                fontSize: 22.0,
                                fontWeight: FontWeight.w600),
                          )
                        ],
                      )),
                ),
              ),
        bottom: TabBar(
          tabs: [
            Tab(
              child: Text("Following"),
            ),
            Tab(
              child: Text("Followers"),
            ),
          ],
          indicatorColor: Colors.white,
          controller: tabController,
        ),
        backgroundColor: Colors.black,
      ),