未弹出“循环进度指示器”的颤振“ showDialog”

Question

未弹出带有“循环进度指示器”的Flutter“ showDialog”。我该如何解决？

void verifyOTP(String smsCode, String username) async {
    var _authCredential = PhoneAuthProvider.credential(
        verificationId: verificationId, smsCode: smsCode);

    showDialog(
        useRootNavigator: false,
        context: context,
        barrierDismissible: true,
        builder: (context) {
          return Container(
            child: Center(
              child: CircularProgressIndicator(),
            ),
          );
        });

    firebaseAuth
        .signInWithCredential(_authCredential)
        .then((UserCredential result) {
      User user = result.user;

      if (user != null) {
        FirebaseFirestore.instance
            .collection('users')
            .doc(user.phoneNumber)
            .set({'username': username, 'phoneNo': user.phoneNumber});

        userAuthorized();
      }

      ///go To Next Page

      Future.delayed(Duration.zero, () {
        Navigator.pop(context);
      });

      Navigator.of(context).pushReplacementNamed(OrdersScreen.routeName);
    }).catchError((error) {
      Navigator.pop(context);
    });
  }