I m getting 3types of errors1) RenderBox was not laid out2) Failed assertion: line 1930 pos 12: 'hasSize' and Null check operator used on a null value

I am creating a todo app that contains TaskList and Task Tiles and by creating check boxes of task lists and using call back functions I got 3 types of errors.

1. RenderBox was not laid out 2) Failed assertion: line 1930 pos 12: 'hasSize' 3)Null check operator used on a null value

TaskList class code:

import 'package:flutter/material.dart';
import 'package:todoey_flutter/widgets/TaskTile.dart';


class TaskList extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ListView(
      children: <Widget>[
        TaskTile(),
        TaskTile(),
      ],
    );
  }
}

TaskTile code that contains checkbox and callback:

import 'package:flutter/material.dart';
class TaskTile extends StatefulWidget {
  @override
  _TaskTileState createState() => _TaskTileState();
}


class _TaskTileState extends State<TaskTile> {
  bool isChecked= false;


  @override
  Widget build(BuildContext context) {
    return ListTile(
      title: Text(
        'This is my task.',
        style: TextStyle(
        decoration: isChecked ? TextDecoration.lineThrough : null,
    ),),
      trailing: TaskCheckBox(isChecked, (bool checkboxState) {
        setState(() {
          isChecked = checkboxState;
        });
      },
      ),
    );
  }
}

class TaskCheckBox extends StatelessWidget {

  TaskCheckBox (this.checkboxState, this.toggleCheckBoxState);
  final bool checkboxState;
  final Function toggleCheckBoxState;


  @override
  Widget build(BuildContext context) {
    return Checkbox(
      activeColor: Colors.blueAccent,
        value: checkboxState,
        onChanged: toggleCheckBoxState(),
    );
  }
}