带你读《深入浅出Dart》三十、Flutter实战之TODO应用（2）

import 'package:flutter/material.dart';import 'package:todo_app/models/todo.dart';
class TodoEditScreen extends StatefulWidget {
  final Todo? todo;
  TodoEditScreen({this.todo});
  @override
  _TodoEditScreenState createState() => _TodoEditScreenState();}
class _TodoEditScreenState extends State {
  late TextEditingController _titleController;
  late TextEditingController _descriptionController;
  bool _isCompleted = false;
  @override
  void initState() {
    super.initState();
    _titleController = TextEditingController(text: widget.todo?.title ?? '');
    _descriptionController =
        TextEditingController(text: widget.todo?.description ?? '');
    _isCompleted = widget.todo?.isCompleted ?? false;
  }
  @override
  void dispose() {
    _titleController.dispose();
    _descriptionController.dispose();
    super.dispose();
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.todo == null ? 'Add Todo' : 'Edit Todo'),
      ),
      body: Padding(
        padding: EdgeInsets.all(16.0),
        child: Column(
          children: [
            TextField(
              controller: _titleController,
              decoration: InputDecoration(
                labelText: 'Title',
              ),
            ),
            SizedBox(height: 16.0),
            TextField(
              controller: _descriptionController,
              decoration: InputDecoration(
                labelText: 'Description',
              ),
            ),
            SizedBox(height: 16.0),
            CheckboxListTile(
              title: Text('Completed'),
              value: _isCompleted,
              onChanged: (value) {
                setState(() {
                  _isCompleted = value!;
                });
              },
            ),
            SizedBox(height: 16.0),
            RaisedButton(
              onPressed: () {
                _saveTodo();
              },
              child: Text('Save'),
            ),
          ],
        ),
      ),
    );
  }
  void _saveTodo() {
    final newTodo = Todo(
      title: _titleController.text,
      description: _descriptionController.text,
      isCompleted: _isCompleted,
    );
    Navigator.pop(context, newTodo);
  }}