title: NoSuchMethodError : The setter 'text=' was called on null. Receiver: null Tried calling: text="2020-12-10 00:00:00.000"
body: <p>I navigate to EditOrderPage and pass some data to it (using which I need to pre-fill TextFormFields)</p>
  <pre><code>onPressed: () {
   Navigator.push(
     context,
     MaterialPageRoute(
       builder: (context) =&gt; EditOrderPage(
         title: &quot;Изменить&quot;,
         date: DateTime.parse(feedbackItems[index].date)
             .toLocal()
             .toString(),
         name: feedbackItems[index].name,
         product: feedbackItems[index].product,
         quantity: feedbackItems[index].quantity,
         discount: feedbackItems[index].discount,
         delivery: feedbackItems[index].delivery,
         payment: feedbackItems[index].payment,
         paymethod: feedbackItems[index].paymethod,
       ),
     ),
   );
  },
  </code></pre>
  <p>Then I have <code>EditOrderScreen</code> which has a state <code>EditOrderPage</code></p>
  <pre><code>class EditOrderScreen extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
        debugShowCheckedModeBanner: false,
        title: 'Feedback Responses',
        theme: ThemeData(
          textTheme: GoogleFonts.montserratTextTheme(
            Theme.of(context).textTheme,
          ),
        ),
        home: EditOrderPage(
          title: &quot;Изменить&quot;,
        ),
      );
    }
  }
  
  class _EditOrderPageState extends State&lt;EditOrderPage&gt; {
    ValueNotifier isActive = ValueNotifier(true);
    final _formKey = GlobalKey&lt;FormState&gt;();
    final _scaffoldKey = GlobalKey&lt;ScaffoldState&gt;();
  
    TextEditingController edateController;
    TextEditingController enameController;
    TextEditingController eproductController;
    TextEditingController equantityController;
    TextEditingController ediscountController;
    TextEditingController epriceController;
    TextEditingController edeliveryController;
    TextEditingController epaymentController;
    TextEditingController epaymethodController;
  
    @override
    void initState() {
      edateController.text = widget.date;
      enameController.text = widget.name;
      eproductController.text = widget.product;
      equantityController.text = widget.quantity;
      ediscountController.text = widget.discount;
      epriceController.text = widget.price;
      edeliveryController.text = widget.delivery;
      epaymentController.text = widget.payment;
      epaymethodController.text = widget.paymethod;
      super.initState();
    }
  }
  </code></pre>
  <p>What is causing the error? (Sorry..looks messy and pretty hard coded ..Just beginner in Flutter*) Thank you ~</p>