error: The argument type 'PickedFile' can't be assigned to the parameter type 'File'. flutter

I'm' getting this error in my code when I'm trying to upload image. I'm new to flutter and struggling with this error. I'm developing a profile detail update section.

• error: The argument type 'PickedFile' can't be assigned to the parameter type 'File'.

how to correct this error in my code. appreciate your help on this.

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'dart:convert';
import 'package:http/http.dart' ;



class CreateProfile extends StatefulWidget {
  CreateProfile({required Key key}) : super(key: key);

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

class _CreateProfileState extends State<CreateProfile> {

  bool circular = false;
  late PickedFile _imageFile;

 final ImagePicker _picker = ImagePicker();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Form(

        child: ListView(
          padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 30),
          children: <Widget>[
            imageProfile(),
            SizedBox(
              height: 20,
            ),
            nameTextField(),
            SizedBox(
              height: 20,
            ),
            professionTextField(),
            SizedBox(
              height: 20,
            ),
            dobField(),
            SizedBox(
              height: 20,
            ),
            titleTextField(),
            SizedBox(
              height: 20,
            ),
            aboutTextField(),
            SizedBox(
              height: 20,
            ),

],
    ),
    ),
    );
              }

  Widget imageProfile() {
    return Center(
      child: Stack(children: <Widget>[
        CircleAvatar(
          radius: 80.0,
          backgroundImage: _imageFile == null
              ? AssetImage("assets/pic.jpg") as ImageProvider
              : FileImage(_imageFile),

        ),
        Positioned(
          bottom: 20.0,
          right: 20.0,
          child: InkWell(
            onTap: () {
              showModalBottomSheet(
                context: context,
                builder: ((builder) => bottomSheet()),
              );
            },
            child: Icon(
              Icons.camera_alt,
              color: Colors.teal,
              size: 28.0,
            ),
          ),
        ),
      ]),
    );
  }

  Widget bottomSheet() {
    return Container(
      height: 100.0,
      width: MediaQuery.of(context).size.width,
      margin: EdgeInsets.symmetric(
        horizontal: 20,
        vertical: 20,
      ),
      child: Column(
        children: <Widget>[
          Text(
            "Choose Profile photo",
            style: TextStyle(
              fontSize: 20.0,
            ),
          ),
          SizedBox(
            height: 20,
          ),
          Row(mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[
            TextButton.icon(
              icon: Icon(Icons.camera),
              onPressed: () {
                takePhoto(ImageSource.camera);
              },
              label: Text("Camera"),
            ),
            TextButton.icon(
              icon: Icon(Icons.image),
              onPressed: () {
                takePhoto(ImageSource.gallery);
              },
              label: Text("Gallery"),
            ),
          ])
        ],
      ),
    );
  }

  void takePhoto(ImageSource source) async {
    final pickedFile = await _picker.pickImage(
      source: source,
    );
    setState(() {
      _imageFile = pickedFile as PickedFile;

    });
  }

  //starting text fields

  Widget nameTextField() {
    return TextFormField(
      //controller: _name,
      validator: (value) {
        if (value!.isEmpty) return "Name can't be empty";

        return null;
      },
      decoration: InputDecoration(
        border: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.teal,
            )),
        focusedBorder: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.orange,
              width: 2,
            )),
        prefixIcon: Icon(
          Icons.person,
          color: Colors.green,
        ),
        labelText: "Name",
        helperText: "Name can't be empty",
        hintText: "Dev Stack",
      ),
    );
  }

  Widget professionTextField() {
    return TextFormField(
      //controller: _profession,
      validator: (value) {
        if (value!.isEmpty) return "Profession can't be empty";

        return null;
      },
      decoration: InputDecoration(
        border: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.teal,
            )),
        focusedBorder: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.orange,
              width: 2,
            )),
        prefixIcon: Icon(
          Icons.person,
          color: Colors.green,
        ),
        labelText: "Profession",
        helperText: "Profession can't be empty",
        hintText: "Full Stack Developer",
      ),
    );
  }

  Widget dobField() {
    return TextFormField(
     // controller: _dob,
      validator: (value) {
        if (value!.isEmpty) return "DOB can't be empty";

        return null;
      },
      decoration: InputDecoration(
        border: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.teal,
            )),
        focusedBorder: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.orange,
              width: 2,
            )),
        prefixIcon: Icon(
          Icons.person,
          color: Colors.green,
        ),
        labelText: "Date Of Birth",
        helperText: "Provide DOB on dd/mm/yyyy",
        hintText: "01/01/2020",
      ),
    );
  }

  Widget titleTextField() {
    return TextFormField(
     // controller: _title,
      validator: (value) {
        if (value!.isEmpty) return "Title can't be empty";

        return null;
      },
      decoration: InputDecoration(
        border: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.teal,
            )),
        focusedBorder: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.orange,
              width: 2,
            )),
        prefixIcon: Icon(
          Icons.person,
          color: Colors.green,
        ),
        labelText: "Title",
        helperText: "It can't be empty",
        hintText: "Flutter Developer",
      ),
    );
  }

  Widget aboutTextField() {
    return TextFormField(
     // controller: _about,
      validator: (value) {
        if (value!.isEmpty) return "About can't be empty";

        return null;
      },
      maxLines: 4,
      decoration: InputDecoration(
        border: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.teal,
            )),
        focusedBorder: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.orange,
              width: 2,
            )),
        labelText: "About",
        helperText: "Write about yourself",
        hintText: "I am Dev Stack",
      ),
    );
  }
}