我的FlatButton恰好在我的文本字段下方，并且每当出现键盘时都会被隐藏

如何解决我的FlatButton恰好在我的文本字段下方，并且每当出现键盘时都会被隐藏

我的平面按钮就在我的文本框下方。每当我的键盘弹出时，flatbutton就会被隐藏。我希望我的键盘一弹出，我的flatbutton也应该随之弹出。如果文本框上方的内容隐藏在上方或滚动上方，我没有问题。您可以检查代码的最后一部分以供参考-

//library international_phone_input;

import 'dart:async';
import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:international_phone_input/src/phone_service.dart';

import 'country.dart';
import 'package:byteseal/components/bottom_button.dart';
import 'package:byteseal/screens/otp_screen1.dart';

class InternationalPhoneInput extends StatefulWidget {
  final void Function(String phoneNumber,String internationalizedPhoneNumber,String isoCode) onPhoneNumberChange;
  final String initialPhoneNumber;
  final String initialSelection;
  final String errorText;
  final String hintText;
  final String labelText;
  final TextStyle errorStyle;
  final TextStyle hintStyle;
  final TextStyle labelStyle;
  final int errorMaxLines;
  final List<String> enabledCountries;
  final InputDecoration decoration;
  final bool showCountryCodes;
  final bool showCountryFlags;
  final Widget dropdownIcon;
  final InputBorder border;
  bool isVisible = false;

  InternationalPhoneInput(
      {this.onPhoneNumberChange,this.initialPhoneNumber,this.initialSelection,this.errorText,this.hintText,this.labelText,this.errorStyle,this.hintStyle,this.labelStyle,this.enabledCountries = const [],this.errorMaxLines,this.decoration,this.showCountryCodes = true,this.showCountryFlags = true,this.dropdownIcon,//this.isVisible,this.border});

  static Future<String> internationalizeNumber(String number,String iso) {
    return PhoneService.getNormalizedPhoneNumber(number,iso);
  }

  @override
  _InternationalPhoneInputState createState() =>
      _InternationalPhoneInputState();
}

class _InternationalPhoneInputState extends State<InternationalPhoneInput> {
  Country selectedItem;
  List<Country> itemList = [];

  String errorText;
  String hintText;
  String labelText;

  TextStyle errorStyle;
  TextStyle hintStyle;
  TextStyle labelStyle;

  int errorMaxLines;

  bool hasError = false;
  bool showCountryCodes;
  bool showCountryFlags;

  InputDecoration decoration;
  Widget dropdownIcon;
  InputBorder border;

  _InternationalPhoneInputState();

  final phoneTextController = TextEditingController();

  @override
  void initState() {
    errorText = widget.errorText ?? 'Please enter a valid phone number';
    hintText = widget.hintText ?? 'eg. 244056345';
    labelText = widget.labelText;
    errorStyle = widget.errorStyle;
    hintStyle = widget.hintStyle;
    labelStyle = widget.labelStyle;
    errorMaxLines = widget.errorMaxLines;
    decoration = widget.decoration;
    showCountryCodes = widget.showCountryCodes;
    showCountryFlags = widget.showCountryFlags;
    dropdownIcon = widget.dropdownIcon;

    phoneTextController.addListener(_validatePhoneNumber);
    phoneTextController.text = widget.initialPhoneNumber;

    _fetchCountryData().then((list) {
      Country preSelectedItem;

      if (widget.initialSelection != null) {
        preSelectedItem = list.firstWhere(
            (e) =>
                (e.code.toUpperCase() ==
                    widget.initialSelection.toUpperCase()) ||
                (e.dialCode == widget.initialSelection.toString()),orElse: () => list[0]);
      } else {
        preSelectedItem = list[0];
      }

      setState(() {
        itemList = list;
        selectedItem = preSelectedItem;
      });
    });

    super.initState();
  }

  _validatePhoneNumber() {
    String phoneText = phoneTextController.text;
    if (phoneText != null && phoneText.isNotEmpty) {
      PhoneService.parsePhoneNumber(phoneText,selectedItem.code)
          .then((isValid) {
        setState(() {
          hasError = !isValid;
        });

        if (widget.onPhoneNumberChange != null) {
          if (isValid) {
            PhoneService.getNormalizedPhoneNumber(phoneText,selectedItem.code)
                .then((number) {
              widget.onPhoneNumberChange(phoneText,number,selectedItem.code);
            });
          } else {
            widget.onPhoneNumberChange('','',selectedItem.code);
          }
        }
      });
    }
  }

  Future<List<Country>> _fetchCountryData() async {
    var list = await DefaultAssetBundle.of(context)
        .loadString('packages/international_phone_input/assets/countries.json');
    List<dynamic> jsonList = json.decode(list);

    List<Country> countries = List<Country>.generate(jsonList.length,(index) {
      Map<String,String> elem = Map<String,String>.from(jsonList[index]);
      if (widget.enabledCountries.isEmpty) {
        return Country(
            name: elem['en_short_name'],code: elem['alpha_2_code'],dialCode: elem['dial_code'],flagUri: 'assets/flags/${elem['alpha_2_code'].toLowerCase()}.png');
      } else if (widget.enabledCountries.contains(elem['alpha_2_code']) ||
          widget.enabledCountries.contains(elem['dial_code'])) {
        return Country(
            name: elem['en_short_name'],flagUri: 'assets/flags/${elem['alpha_2_code'].toLowerCase()}.png');
      } else {
        return null;
      }
    });

    countries.removeWhere((value) => value == null);

    return countries;
  }

  int sum = 0;
  String isonum;
  bool isVisible = false;
  bool visibility() {
    return isVisible;
  }
  String pno;

  @override
  Widget build(BuildContext context) {
    return Container(
      child: Column(
        children : <Widget>[
        Row(
        mainAxisAlignment: MainAxisAlignment.start,children: <Widget>[
          DropdownButtonHideUnderline(
            child: Padding(
              padding: EdgeInsets.only(top: 8),child: DropdownButton<Country>(
                value: selectedItem,icon: Padding(
                  padding:
                      EdgeInsets.only(bottom: (decoration != null) ? 6 : 0),child: dropdownIcon ?? Icon(Icons.arrow_drop_down),),onChanged: (Country newValue) {
                  setState(() {
                    selectedItem = newValue;
                  });
                  _validatePhoneNumber();
                },items: itemList.map<DropdownMenuItem<Country>>((Country value) {
                  return DropdownMenuItem<Country>(
                    value: value,child: Container(
                      padding: const EdgeInsets.only(bottom: 5.0),child: Row(
                        mainAxisAlignment: MainAxisAlignment.spaceEvenly,children: <Widget>[
                          if (showCountryFlags) ...[
                            Image.asset(
                              value.flagUri,width: 32.0,package: 'international_phone_input',)
                          ],if (showCountryCodes) ...[
                            SizedBox(width: 4),Text(value.dialCode,style: TextStyle(color: Colors.white),)
                          ]
                        ],);
                }).toList(),Flexible(
              child: GestureDetector(
                 child: TextField(
                   onChanged: (text){
                     sum+=1;
                     setState(() {
                       if(sum>9) {
                         isVisible=true;
                       }
                     });
                   },onSubmitted: (text) {
                     pno = text;
                   },keyboardType: TextInputType.phone,style: TextStyle(
                   color: Colors.white,controller: phoneTextController,decoration: decoration ??
                        InputDecoration(
                          hintText: hintText,labelText: labelText,errorText: hasError ? errorText : null,hintStyle: hintStyle ?? null,errorStyle: errorStyle ?? null,labelStyle: labelStyle,errorMaxLines: errorMaxLines ?? 3,border: border ?? null,)
          )
        ],Padding(
            padding: EdgeInsets.symmetric(horizontal: 10.0),child: Container(
              height: 1.0,width: 360.0,color: Colors.white,Visibility(
             visible: isVisible,child: BottomButton(
                 buttonTitle: 'Next',onTap: () {
                   Navigator.push(
                     context,MaterialPageRoute(
                       builder: (context) => OTPScreen(number: pno,iso: isonum),)
                   );
                 }),]
      )
    );
  }
}