Flutter PageView The method jumpToPage was called on null

Question

I'm new to dart and i tried to implement a BottomNaviagtor. I want to jump to a specific page when the BottomNavigatorItem is tapped.

Below is the error i'm getting:

I/flutter ( 2447): ══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════

I/flutter ( 2447): The following NoSuchMethodError was thrown while handling a gesture:

I/flutter ( 2447): The method 'jumpToPage' was called on null.

I/flutter ( 2447): Receiver: null

I/flutter ( 2447): Tried calling: jumpToPage(2)

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:skypeclone/utils/universal_variables.dart';

class HomeScreen extends StatefulWidget {
  @override
  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  PageController pageController;
  int _page = 0;

  @override
  void initState() {
    super.initState();
    pageController = PageController();
  }

  void onPageChanged(int page) {
    setState(() {
      _page = page;
    });
  }

  void navigationTapped(int page) {
    pageController.jumpToPage(page);
  }

  @override
  Widget build(BuildContext context) {
    double _labelFontSize = 10;

    return Scaffold(
      backgroundColor: UniversalVariables.blackColor,
      body: PageView(
        children: <Widget>[
          Center(
              child: Text(
            "Chat List Screen",
            style: TextStyle(color: Colors.white),
          )),
          Center(
              child: Text(
            "Call Logs",
            style: TextStyle(color: Colors.white),
          )),
          Center(
              child: Text(
            "Contact Screen",
            style: TextStyle(color: Colors.white),
          )),
        ],
        controller: pageController,
        onPageChanged: onPageChanged,
      ),
      bottomNavigationBar: Container(
        child: Padding(
          padding: EdgeInsets.symmetric(vertical: 10),
          child: CupertinoTabBar(
            backgroundColor: UniversalVariables.blackColor,
            items: <BottomNavigationBarItem>[
              BottomNavigationBarItem(
                icon: Icon(Icons.chat,
                    color: (_page == 0)
                        ? UniversalVariables.lightBlueColor
                        : UniversalVariables.greyColor),
                title: Text(
                  "Chats",
                  style: TextStyle(
                      fontSize: _labelFontSize,
                      color: (_page == 0)
                          ? UniversalVariables.lightBlueColor
                          : Colors.grey),
                ),
              ),
              BottomNavigationBarItem(
                icon: Icon(Icons.call,
                    color: (_page == 1)
                        ? UniversalVariables.lightBlueColor
                        : UniversalVariables.greyColor),
                title: Text(
                  "Calls",
                  style: TextStyle(
                      fontSize: _labelFontSize,
                      color: (_page == 1)
                          ? UniversalVariables.lightBlueColor
                          : Colors.grey),
                ),
              ),
              BottomNavigationBarItem(
                icon: Icon(Icons.contact_phone,
                    color: (_page == 2)
                        ? UniversalVariables.lightBlueColor
                        : UniversalVariables.greyColor),
                title: Text(
                  "Contacts",
                  style: TextStyle(
                      fontSize: _labelFontSize,
                      color: (_page == 2)
                          ? UniversalVariables.lightBlueColor
                          : Colors.grey),
                ),
              ),
            ],
            onTap: navigationTapped,
            currentIndex: _page,
          ),
        ),
      ),
    );
  }
}

Answer 1

PageController _controller = PageController(
    initialPage: 0,
);

Shouldn't the initialPage be declared in the controller ? And also you need to dispose the controller, like

@override
void dispose() {
  _controller.dispose();
  super.dispose();
}