How to using TextEditingController

Question

I make a page to verify a phone number and then verify the OTP on a second page. Now my problem is I can send the phone number and can't go to the OTP verify page.
phone: +60176713856 otp: 134679

But I also need to send data of TextEditingController (patientnumberController) values from this page:

    import 'package:flutter/material.dart';
    import 'package:nodejs_jwt/api_service.dart';
    import 'package:snippet_coder_utils/FormHelper.dart';
    import 'package:snippet_coder_utils/ProgressHUD.dart';
    import 'package:snippet_coder_utils/hex_color.dart';
    
    import 'otp_verify_page.dart';
    
    class LoginOTPPage extends StatefulWidget {
      const LoginOTPPage({Key? key}) : super(key: key);
    
      _LoginOTPageState createState() => _LoginOTPageState();
    }
    
    class _LoginOTPageState extends State<LoginOTPPage> {
      String mobileNo = '+60176713856';
      bool isAPICallProcess = false;
    
      @override
      Widget build(BuildContext context) {
        final patientPhoneNumberController = TextEditingController();
    
        
        return SafeArea(
          child: Scaffold(
            body: ProgressHUD(
              child: loginUI(),
              inAsyncCall: isAPICallProcess,
              opacity: .3,
              key: UniqueKey(),
            ),
          ),
        );
      }
    
      loginUI() {
        return Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Image.network(
              "https://i.imgur.com/bOCEVJg.png",
              height: 180,
              fit: BoxFit.contain,
            ),
            Padding(
              padding: const EdgeInsets.only(top: 10),
              child: Center(
                child: Text(
                  "Login Mobile Number",
                  style: TextStyle(
                    fontSize: 20,
                    fontWeight: FontWeight.bold,
                  ),
                ),
              ),
            ),
            const SizedBox(
              height: 10,
            ),
            const Center(
              child: Text(
                "Enter Patient Phone Number",
                style: TextStyle(
                  fontSize: 14,
                ),
              ),
            ),
            const SizedBox(
              height: 10,
            ),
            Padding(
              padding: const EdgeInsets.fromLTRB(20, 0, 20, 0),
              child: Row(
                mainAxisAlignment: MainAxisAlignment.start,
                crossAxisAlignment: CrossAxisAlignment.center,
                children: [
                  Flexible(
                    child: Container(
                      height: 47,
                      width: 50,
                      margin: const EdgeInsets.fromLTRB(0, 10, 3, 30),
                      decoration: BoxDecoration(
                        borderRadius: BorderRadius.circular(4),
                        border: Border.all(
                          color: Colors.grey,
                        ),
                      ),
                      child: const Center(
                        child: Text(
                          "",
                          style: TextStyle(
                            color: Colors.black,
                            fontWeight: FontWeight.bold,
                          ),
                        ),
                      ),
                    ),
                  ),
                  Flexible(
                    flex: 5,
                    child: TextFormField(
                      maxLines: 1,
                      maxLength: 10,
                      decoration: const InputDecoration(
                        contentPadding: EdgeInsets.all(6),
                        enabledBorder: OutlineInputBorder(
                          borderSide: BorderSide(color: Colors.green, width: 1),
                        ),
                        border: OutlineInputBorder(
                          borderSide: BorderSide(
                            color: Colors.grey,
                            width: 1,
                          ),
                        ),
                        focusedBorder: OutlineInputBorder(
                          borderSide: BorderSide(
                            color: Colors.blue,
                            width: 1,
                          ),
                        ),
                      ),
                      initialValue: mobileNo,
                      keyboardType: TextInputType.number,
                      onChanged: (String value) {
                        if (value.length >= 9) {
                          mobileNo = "+60" + value;
                        }
                      },
                    ),
                  )
                ],
              ),
            ),
            Center(
              child: FormHelper.submitButton(
                "Continue",
                () async {
                  if (mobileNo.length >= 9) {
                    setState(() {
                      isAPICallProcess = true;
                    });
                    APIService.signin(mobileNo).then((respone) async {
                      setState(() {
                        isAPICallProcess = false;
                      });
                      if (respone) {
                        Navigator.pushAndRemoveUntil(
                          context,
                          MaterialPageRoute(
                            builder: (context) => OtpVerifyPage(
                              mobileNo: mobileNo,
                            ),
                          ),
                          (route) => false,
                        );
                      }
                    });
                  }
                },
                borderColor: HexColor("#78D0B1"),
                btnColor: HexColor("#78D0B1"),
                txtColor: HexColor("#000000"),
                borderRadius: 20,
              ),
            )
          ],
        );
      }
    }
    

---

and send data of TextEditingController (otpverfyController) values from this page:

    import 'package:flutter/material.dart';
    import 'package:sms_autofill/sms_autofill.dart';
    import 'package:snippet_coder_utils/FormHelper.dart';
    import 'package:snippet_coder_utils/ProgressHUD.dart';
    import 'package:snippet_coder_utils/hex_color.dart';
    
    import 'api_service.dart';
    import 'appointments_list.dart';
    
    class OtpVerifyPage extends StatefulWidget {
      final String? mobileNo;
      const OtpVerifyPage({
        Key? key,
        this.mobileNo,
      }) : super(key: key);
    
      @override
      _OtpVerifyPageState createState() => _OtpVerifyPageState();
    }
    
    class _OtpVerifyPageState extends State<OtpVerifyPage> {
      String _otpCode = "134679";
      final int _otpCodeLength = 6;
      bool isAPICallProcess = false;
      late FocusNode myFocusNode;
    
      @override
      void initState() {
        super.initState();
        myFocusNode = FocusNode();
        myFocusNode.requestFocus();
    
        SmsAutoFill().listenForCode.call();
      }
    
      @override
      Widget build(BuildContext context) {
        return SafeArea(
          child: Scaffold(
            body: ProgressHUD(
              child: verifyOtpUI(),
              inAsyncCall: isAPICallProcess,
              opacity: .3,
              key: UniqueKey(),
            ),
          ),
        );
      }
    
      verifyOtpUI() {
        return Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            Image.network(
              "https://i.imgur.com/6aiRpKT.png",
              height: 180,
              fit: BoxFit.contain,
            ),
            const Padding(
              padding: EdgeInsets.only(top: 20),
              child: Text(
                "OTP Verification",
                style: TextStyle(
                  fontSize: 20,
                  fontWeight: FontWeight.bold,
                ),
              ),
            ),
            const SizedBox(
              height: 10,
            ),
            Center(
              child: Text(
                "Enter OTP code \n+60-${widget.mobileNo}",
                maxLines: 2,
                textAlign: TextAlign.center,
                style: const TextStyle(
                  fontSize: 14,
                ),
              ),
            ),
            Padding(
              padding: const EdgeInsets.fromLTRB(25, 0, 25, 0),
              child: PinFieldAutoFill(
                decoration: UnderlineDecoration(
                  textStyle: const TextStyle(
                    fontSize: 20,
                    color: Colors.black,
                  ),
                  colorBuilder: FixedColorBuilder(Colors.black.withOpacity(.3)),
                ),
                currentCode: _otpCode,
                codeLength: _otpCodeLength,
                onCodeChanged: (code) {
                  if (code!.length == _otpCodeLength) {
                    _otpCode = code;
                    FocusScope.of(context).requestFocus(FocusNode());
                  }
                },
              ),
            ),
            const SizedBox(
              height: 20,
            ),
            Center(
              child: FormHelper.submitButton(
                "Verify",
                () async {
                  if (_otpCode.isNotEmpty) {
                    setState(() {
                      isAPICallProcess = true;
                    });
                    APIService.verifyOTP(_otpCode).then((respone) async {
                      setState(() {
                        isAPICallProcess = false;
                      });
                      if (respone!.isNotEmpty) {
                        Navigator.pushAndRemoveUntil(
                          context,
                          MaterialPageRoute(
                            builder: (context) => AppointmentList(
                              token: respone,
                            ),
                          ),
                          (route) => false,
                        );
                      }
                    });
                  }
                },
                borderColor: HexColor("#78D0B1"),
                btnColor: HexColor("#78D0B1"),
                txtColor: HexColor("#000000"),
                borderRadius: 20,
              ),
            )
          ],
        );
      }
    
      @override
      void dispose() {
        SmsAutoFill().unregisterListener();
        myFocusNode.dispose();
        super.dispose();
      }
    }

Answer 1

let me know if i am getting you correct .............

to send the the data of textediting controller to the next screen first assign the TexteditingControler to the controller property of the text field from where you want to get the user input after while navigating make a new variable at the receiver side same as you have done for mobile number and assigin texteditingcontrolller.text property to that variable like

    Navigator.pushAndRemoveUntil(
                      context,
                      MaterialPageRoute(
                        builder: (context) => OtpVerifyPage(
                         controlllervalue : texteditingController.text,
                        ),
                      ),