使用 sharedPrefrences 或 JSON 保存用户数据（采用我的 class 格式）
Saving user data(which is in my class format) with sharedPrefrences or JSON
刚学完Flutter的课程，上一个项目是一个简单的Todo-List，关掉app后没有任务，真是苦恼。
课程的完整代码是 here
我的代码完全没有区别：
我非常喜欢提供程序和任务 class 的工作方式，所以我不想更改它，所以我尝试按原样保存数据，方法是制作两个列表，一个用于字符串，另一个用于布尔值取出来保存（写入），然后读取并放回原处（读取）
理论上像这样——循环内的 Task(StringList[index],boolList[index])——作为 Task class; 的方面当我尝试使用 SharedPreferences 保存时，我制作了一个虚拟代码，使添加任务不起作用
任何节省方式都会有所帮助，我的虚拟想法或任何东西。
'data' class 其中 sharedPreferences 尝试：
import 'dart:collection';
import 'package:flutter/foundation.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'tasks.dart';
class TaskData extends ChangeNotifier{
List<Task> _tasks = [];
UnmodifiableListView<Task> get tasks => UnmodifiableListView(_tasks);
int get taskCount => _tasks.length;
String _string;
String _bool;
void addTask(String newTaskName) async{
final task = Task(name: newTaskName);
_tasks.add(task);
// here is the code
SharedPreferences sPref = await SharedPreferences.getInstance();
List<SharedPreferences> sPrefs =[];
SharedPreferences bPref = await SharedPreferences.getInstance();
List<SharedPreferences> bPrefs =[];
for(var item = 0; item <= taskCount; item++){
//String Preferences
sPref.setString(_string, tasks[item].name);
sPrefs.add(sPref);
//boolean Preferences
bPref.setBool(_bool,tasks[item].isDone);
bPrefs.add(bPref);
}
// code is finished
notifyListeners();
}
void updateTask(Task task){
task.toggleIsDone();
notifyListeners();
}
void removeTask(Task task){
_tasks.remove(task);
notifyListeners();
}
}
tasks class（数据保存在tasks数组中的方式）
class Task {
final String name;
bool isDone;
Task({this.name, this.isDone = false});
void toggleIsDone() {
isDone = !isDone;
}
}
现在有其他 class 涉及但与 github 代码
没有区别
添加任务：
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:provider/provider.dart';
import 'package:todoey_flutter/components/constants.dart';
import 'package:todoey_flutter/modules/task_data.dart';
class AddTaskScreen extends StatelessWidget {
final controller = TextEditingController();
@override
Widget build(BuildContext context) {
String userTask;
return Container(
color: Color(0xFF737373),
height: 600,
child: Container(
padding: EdgeInsets.all(36.0),
decoration: kContainerBoxRadius,
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Text(
'Add a Task',
style: TextStyle(
color: Colors.lightBlueAccent,
fontSize: 36,
fontWeight: FontWeight.w300),
textAlign: TextAlign.center,
),
Padding(
padding: EdgeInsets.symmetric(horizontal: 12.0),
child: TextField(
style: TextStyle(
fontSize: 24.0,
fontWeight: FontWeight.w400,
color: Colors.lightBlueAccent.shade700),
onChanged: (inputTask) {
userTask = inputTask;
},
autofocus: true,
cursorRadius: Radius.circular(32.0),
enableSuggestions: true,
enabled: true,
expands: false,
controller: controller,
textAlign: TextAlign.center,
),
),
SizedBox(
height: 12.0,
),
MaterialButton(
onPressed: () {
if (userTask == null) {}
else {
controller.clear();
Provider.of<TaskData>(context).addTask(userTask);
print(TaskData().taskCount);
Navigator.pop(context);
}
},
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Text(
'ADD',
style: TextStyle(
fontSize: 22.0,
fontWeight: FontWeight.bold,
color: Colors.white),
),
),
color: Colors.lightBlueAccent,
),
],
),
),
);
}
}
任务列表：
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:provider/provider.dart';
import 'package:todoey_flutter/modules/task_data.dart';
import 'task_tile.dart';
class TaskList extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Consumer<TaskData>(
builder: (context, taskData, child) {
return ListView.builder(
itemBuilder: (context, index) {
final task = taskData.tasks[index];
return TaskTile(
text: task.name,
isChecked: task.isDone,
toggleCheckBoxState: (bool newValue) =>
taskData.updateTask(task),
longPressIdentify: () => taskData.removeTask(task),
);
},
itemCount: taskData.taskCount,
);
},
);
}
}
TaskTile class 带有一些构造函数，Task class 或其中的数据没有用处
最后从main.dart>>（供应商所在的地方）任务屏幕class：
//a lot of imports mainly task_data and task list and provider and adding tasks class
class TaskScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.lightBlueAccent,
floatingActionButton: Padding(
padding: const EdgeInsets.only(bottom: 42.0, right: 36.0),
child: FloatingActionButton(
child: Icon(
Icons.add,
size: 48.0,
color: Colors.white,
),
backgroundColor: Colors.lightBlueAccent,
onPressed: () {
showModalBottomSheet(
context: context,
builder: (context) => AddTaskScreen(),
);
}),
),
body: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Container(
padding: EdgeInsets.only(
left: 50.0, top: 120.0, right: 30.0, bottom: 50.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
CircleAvatar(
child: Icon(
Icons.list,
color: Colors.lightBlueAccent,
size: 60.0,
),
backgroundColor: Colors.white,
radius: 40.0,
),
SizedBox(
height: 36.0,
),
Text(
'Todoey',
style: TextStyle(
color: Colors.white,
fontWeight: FontWeight.w800,
fontSize: 55.0,
),
),
SizedBox(
height: 4.0,
),
Padding(
padding: const EdgeInsets.only(left: 8.0),
child: Text(
'${Provider.of<TaskData>(context).taskCount} Tasks',
style: TextStyle(
color: Colors.white,
fontSize: 18.0,
),
),
),
],
),
),
Expanded(
child: Container(
decoration: kContainerBoxRadius,
child: TaskList(),
),
),
]),
);
}
}
抱歉，我没有删除布局代码，所以代码块变大了
提前致谢。
您可以复制粘贴 运行 下面的完整代码
可以将List<Task>转成JSON字符串，直接保存这个JSON字符串
当您的 APP init() 时，您可以读取此 JSON 字符串并转换回 List<Task>
代码片段
void main() {
runApp(MultiProvider(
providers: [
ChangeNotifierProvider(
create: (context) => TaskData()..init(),
),
],
child: MyApp(),
));
}
List<Task> taskFromJson(String str) =>
List<Task>.from(json.decode(str).map((x) => Task.fromJson(x)));
String taskToJson(List<Task> data) =>
json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
void init() async {
SharedPreferences sPref = await SharedPreferences.getInstance();
String jsonTask = sPref.getString("task");
print(jsonTask);
if (jsonTask != null) {
_tasks = taskFromJson(jsonTask);
notifyListeners();
}
}
void saveToPreference() async {
SharedPreferences sPref = await SharedPreferences.getInstance();
sPref.setString("task", taskToJson(_tasks));
}
void addTask(String newTaskName) async {
final task = Task(name: newTaskName);
_tasks.add(task);
await saveToPreference();
notifyListeners();
}
工作演示
完整代码
import 'dart:collection';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:shared_preferences/shared_preferences.dart';
class TaskTile extends StatelessWidget {
final bool isChecked;
final String text;
final Function toggleCheckBoxState;
final Function longPressIdentify;
TaskTile(
{this.isChecked,
this.text,
this.toggleCheckBoxState,
this.longPressIdentify});
@override
Widget build(BuildContext context) {
return ListTile(
onLongPress: longPressIdentify,
title: Text(
text,
style: TextStyle(
decoration: isChecked ? TextDecoration.lineThrough : null),
),
trailing: Checkbox(
activeColor: Colors.lightBlueAccent,
value: isChecked,
onChanged: toggleCheckBoxState,
),
);
}
}
class TaskList extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Consumer<TaskData>(
builder: (context, taskData, child) {
return ListView.builder(
itemBuilder: (context, index) {
final task = taskData.tasks[index];
return TaskTile(
text: task.name,
isChecked: task.isDone,
toggleCheckBoxState: (bool newValue) => taskData.updateTask(task),
longPressIdentify: () => taskData.removeTask(task),
);
},
itemCount: taskData.taskCount,
);
},
);
}
}
class AddTaskScreen extends StatefulWidget {
@override
_AddTaskScreenState createState() => _AddTaskScreenState();
}
class _AddTaskScreenState extends State<AddTaskScreen> {
final controller = TextEditingController();
String userTask;
@override
Widget build(BuildContext context) {
return Container(
color: Color(0xFF737373),
height: 600,
child: Container(
padding: EdgeInsets.all(36.0),
//decoration: kContainerBoxRadius,
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Text(
'Add a Task',
style: TextStyle(
color: Colors.lightBlueAccent,
fontSize: 36,
fontWeight: FontWeight.w300),
textAlign: TextAlign.center,
),
Padding(
padding: EdgeInsets.symmetric(horizontal: 12.0),
child: TextField(
style: TextStyle(
fontSize: 24.0,
fontWeight: FontWeight.w400,
color: Colors.lightBlueAccent.shade700),
onChanged: (inputTask) {
userTask = inputTask;
},
//autofocus: true,
cursorRadius: Radius.circular(32.0),
enableSuggestions: true,
enabled: true,
expands: false,
controller: controller,
textAlign: TextAlign.center,
),
),
SizedBox(
height: 12.0,
),
MaterialButton(
onPressed: () {
print(controller.text);
print("onpressed $userTask");
if (userTask == null) {
} else {
controller.clear();
Provider.of<TaskData>(context, listen: false)
.addTask(userTask);
print(TaskData().taskCount);
Navigator.pop(context);
}
},
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Text(
'ADD',
style: TextStyle(
fontSize: 22.0,
fontWeight: FontWeight.bold,
color: Colors.white),
),
),
color: Colors.lightBlueAccent,
),
],
),
),
);
}
}
List<Task> taskFromJson(String str) =>
List<Task>.from(json.decode(str).map((x) => Task.fromJson(x)));
String taskToJson(List<Task> data) =>
json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
class Task {
final String name;
bool isDone;
Task({this.name, this.isDone = false});
void toggleIsDone() {
isDone = !isDone;
}
factory Task.fromJson(Map<String, dynamic> json) => Task(
name: json["name"],
isDone: json["isDone"],
);
Map<String, dynamic> toJson() => {
"name": name,
"isDone": isDone,
};
}
class TaskData extends ChangeNotifier {
List<Task> _tasks = [];
UnmodifiableListView<Task> get tasks => UnmodifiableListView(_tasks);
int get taskCount => _tasks.length;
String _string;
String _bool;
void init() async {
SharedPreferences sPref = await SharedPreferences.getInstance();
String jsonTask = sPref.getString("task");
print(jsonTask);
if (jsonTask != null) {
_tasks = taskFromJson(jsonTask);
notifyListeners();
}
}
void saveToPreference() async {
SharedPreferences sPref = await SharedPreferences.getInstance();
sPref.setString("task", taskToJson(_tasks));
}
void addTask(String newTaskName) async {
final task = Task(name: newTaskName);
_tasks.add(task);
await saveToPreference();
notifyListeners();
}
void updateTask(Task task) async {
task.toggleIsDone();
await saveToPreference();
notifyListeners();
}
void removeTask(Task task) async {
_tasks.remove(task);
await saveToPreference();
notifyListeners();
}
}
class TaskScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.lightBlueAccent,
floatingActionButton: Padding(
padding: const EdgeInsets.only(bottom: 42.0, right: 36.0),
child: FloatingActionButton(
child: Icon(
Icons.add,
size: 48.0,
color: Colors.white,
),
backgroundColor: Colors.lightBlueAccent,
onPressed: () {
showModalBottomSheet(
context: context,
builder: (context) => AddTaskScreen(),
);
}),
),
body: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Container(
padding: EdgeInsets.only(
left: 50.0, top: 120.0, right: 30.0, bottom: 50.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
CircleAvatar(
child: Icon(
Icons.list,
color: Colors.lightBlueAccent,
size: 60.0,
),
backgroundColor: Colors.white,
radius: 40.0,
),
SizedBox(
height: 36.0,
),
Text(
'Todoey',
style: TextStyle(
color: Colors.white,
fontWeight: FontWeight.w800,
fontSize: 55.0,
),
),
SizedBox(
height: 4.0,
),
Padding(
padding: const EdgeInsets.only(left: 8.0),
child: Text(
'${Provider.of<TaskData>(context).taskCount} Tasks',
style: TextStyle(
color: Colors.white,
fontSize: 18.0,
),
),
),
],
),
),
Expanded(
child: Container(
//decoration: kContainerBoxRadius,
child: TaskList(),
),
),
]),
);
}
}
void main() {
runApp(MultiProvider(
providers: [
ChangeNotifierProvider(
create: (context) => TaskData()..init(),
),
],
child: MyApp(),
));
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
home: TaskScreen(),
);
}
}
刚学完Flutter的课程，上一个项目是一个简单的Todo-List，关掉app后没有任务，真是苦恼。 课程的完整代码是 here
我的代码完全没有区别：
我非常喜欢提供程序和任务 class 的工作方式，所以我不想更改它，所以我尝试按原样保存数据，方法是制作两个列表，一个用于字符串，另一个用于布尔值取出来保存（写入），然后读取并放回原处（读取）
理论上像这样——循环内的 Task(StringList[index],boolList[index])——作为 Task class; 的方面当我尝试使用 SharedPreferences 保存时，我制作了一个虚拟代码，使添加任务不起作用
任何节省方式都会有所帮助，我的虚拟想法或任何东西。
'data' class 其中 sharedPreferences 尝试：
import 'dart:collection';
import 'package:flutter/foundation.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'tasks.dart';
class TaskData extends ChangeNotifier{
List<Task> _tasks = [];
UnmodifiableListView<Task> get tasks => UnmodifiableListView(_tasks);
int get taskCount => _tasks.length;
String _string;
String _bool;
void addTask(String newTaskName) async{
final task = Task(name: newTaskName);
_tasks.add(task);
// here is the code
SharedPreferences sPref = await SharedPreferences.getInstance();
List<SharedPreferences> sPrefs =[];
SharedPreferences bPref = await SharedPreferences.getInstance();
List<SharedPreferences> bPrefs =[];
for(var item = 0; item <= taskCount; item++){
//String Preferences
sPref.setString(_string, tasks[item].name);
sPrefs.add(sPref);
//boolean Preferences
bPref.setBool(_bool,tasks[item].isDone);
bPrefs.add(bPref);
}
// code is finished
notifyListeners();
}
void updateTask(Task task){
task.toggleIsDone();
notifyListeners();
}
void removeTask(Task task){
_tasks.remove(task);
notifyListeners();
}
}
tasks class（数据保存在tasks数组中的方式）
class Task {
final String name;
bool isDone;
Task({this.name, this.isDone = false});
void toggleIsDone() {
isDone = !isDone;
}
}
现在有其他 class 涉及但与 github 代码
没有区别添加任务：
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:provider/provider.dart';
import 'package:todoey_flutter/components/constants.dart';
import 'package:todoey_flutter/modules/task_data.dart';
class AddTaskScreen extends StatelessWidget {
final controller = TextEditingController();
@override
Widget build(BuildContext context) {
String userTask;
return Container(
color: Color(0xFF737373),
height: 600,
child: Container(
padding: EdgeInsets.all(36.0),
decoration: kContainerBoxRadius,
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Text(
'Add a Task',
style: TextStyle(
color: Colors.lightBlueAccent,
fontSize: 36,
fontWeight: FontWeight.w300),
textAlign: TextAlign.center,
),
Padding(
padding: EdgeInsets.symmetric(horizontal: 12.0),
child: TextField(
style: TextStyle(
fontSize: 24.0,
fontWeight: FontWeight.w400,
color: Colors.lightBlueAccent.shade700),
onChanged: (inputTask) {
userTask = inputTask;
},
autofocus: true,
cursorRadius: Radius.circular(32.0),
enableSuggestions: true,
enabled: true,
expands: false,
controller: controller,
textAlign: TextAlign.center,
),
),
SizedBox(
height: 12.0,
),
MaterialButton(
onPressed: () {
if (userTask == null) {}
else {
controller.clear();
Provider.of<TaskData>(context).addTask(userTask);
print(TaskData().taskCount);
Navigator.pop(context);
}
},
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Text(
'ADD',
style: TextStyle(
fontSize: 22.0,
fontWeight: FontWeight.bold,
color: Colors.white),
),
),
color: Colors.lightBlueAccent,
),
],
),
),
);
}
}
任务列表：
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:provider/provider.dart';
import 'package:todoey_flutter/modules/task_data.dart';
import 'task_tile.dart';
class TaskList extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Consumer<TaskData>(
builder: (context, taskData, child) {
return ListView.builder(
itemBuilder: (context, index) {
final task = taskData.tasks[index];
return TaskTile(
text: task.name,
isChecked: task.isDone,
toggleCheckBoxState: (bool newValue) =>
taskData.updateTask(task),
longPressIdentify: () => taskData.removeTask(task),
);
},
itemCount: taskData.taskCount,
);
},
);
}
}
TaskTile class 带有一些构造函数，Task class 或其中的数据没有用处
最后从main.dart>>（供应商所在的地方）任务屏幕class：
//a lot of imports mainly task_data and task list and provider and adding tasks class
class TaskScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.lightBlueAccent,
floatingActionButton: Padding(
padding: const EdgeInsets.only(bottom: 42.0, right: 36.0),
child: FloatingActionButton(
child: Icon(
Icons.add,
size: 48.0,
color: Colors.white,
),
backgroundColor: Colors.lightBlueAccent,
onPressed: () {
showModalBottomSheet(
context: context,
builder: (context) => AddTaskScreen(),
);
}),
),
body: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Container(
padding: EdgeInsets.only(
left: 50.0, top: 120.0, right: 30.0, bottom: 50.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
CircleAvatar(
child: Icon(
Icons.list,
color: Colors.lightBlueAccent,
size: 60.0,
),
backgroundColor: Colors.white,
radius: 40.0,
),
SizedBox(
height: 36.0,
),
Text(
'Todoey',
style: TextStyle(
color: Colors.white,
fontWeight: FontWeight.w800,
fontSize: 55.0,
),
),
SizedBox(
height: 4.0,
),
Padding(
padding: const EdgeInsets.only(left: 8.0),
child: Text(
'${Provider.of<TaskData>(context).taskCount} Tasks',
style: TextStyle(
color: Colors.white,
fontSize: 18.0,
),
),
),
],
),
),
Expanded(
child: Container(
decoration: kContainerBoxRadius,
child: TaskList(),
),
),
]),
);
}
}
抱歉，我没有删除布局代码，所以代码块变大了 提前致谢。
您可以复制粘贴 运行 下面的完整代码
可以将List<Task>转成JSON字符串，直接保存这个JSON字符串
当您的 APP init() 时，您可以读取此 JSON 字符串并转换回 List<Task>
代码片段
void main() {
runApp(MultiProvider(
providers: [
ChangeNotifierProvider(
create: (context) => TaskData()..init(),
),
],
child: MyApp(),
));
}
List<Task> taskFromJson(String str) =>
List<Task>.from(json.decode(str).map((x) => Task.fromJson(x)));
String taskToJson(List<Task> data) =>
json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
void init() async {
SharedPreferences sPref = await SharedPreferences.getInstance();
String jsonTask = sPref.getString("task");
print(jsonTask);
if (jsonTask != null) {
_tasks = taskFromJson(jsonTask);
notifyListeners();
}
}
void saveToPreference() async {
SharedPreferences sPref = await SharedPreferences.getInstance();
sPref.setString("task", taskToJson(_tasks));
}
void addTask(String newTaskName) async {
final task = Task(name: newTaskName);
_tasks.add(task);
await saveToPreference();
notifyListeners();
}
工作演示
完整代码
import 'dart:collection';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:shared_preferences/shared_preferences.dart';
class TaskTile extends StatelessWidget {
final bool isChecked;
final String text;
final Function toggleCheckBoxState;
final Function longPressIdentify;
TaskTile(
{this.isChecked,
this.text,
this.toggleCheckBoxState,
this.longPressIdentify});
@override
Widget build(BuildContext context) {
return ListTile(
onLongPress: longPressIdentify,
title: Text(
text,
style: TextStyle(
decoration: isChecked ? TextDecoration.lineThrough : null),
),
trailing: Checkbox(
activeColor: Colors.lightBlueAccent,
value: isChecked,
onChanged: toggleCheckBoxState,
),
);
}
}
class TaskList extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Consumer<TaskData>(
builder: (context, taskData, child) {
return ListView.builder(
itemBuilder: (context, index) {
final task = taskData.tasks[index];
return TaskTile(
text: task.name,
isChecked: task.isDone,
toggleCheckBoxState: (bool newValue) => taskData.updateTask(task),
longPressIdentify: () => taskData.removeTask(task),
);
},
itemCount: taskData.taskCount,
);
},
);
}
}
class AddTaskScreen extends StatefulWidget {
@override
_AddTaskScreenState createState() => _AddTaskScreenState();
}
class _AddTaskScreenState extends State<AddTaskScreen> {
final controller = TextEditingController();
String userTask;
@override
Widget build(BuildContext context) {
return Container(
color: Color(0xFF737373),
height: 600,
child: Container(
padding: EdgeInsets.all(36.0),
//decoration: kContainerBoxRadius,
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Text(
'Add a Task',
style: TextStyle(
color: Colors.lightBlueAccent,
fontSize: 36,
fontWeight: FontWeight.w300),
textAlign: TextAlign.center,
),
Padding(
padding: EdgeInsets.symmetric(horizontal: 12.0),
child: TextField(
style: TextStyle(
fontSize: 24.0,
fontWeight: FontWeight.w400,
color: Colors.lightBlueAccent.shade700),
onChanged: (inputTask) {
userTask = inputTask;
},
//autofocus: true,
cursorRadius: Radius.circular(32.0),
enableSuggestions: true,
enabled: true,
expands: false,
controller: controller,
textAlign: TextAlign.center,
),
),
SizedBox(
height: 12.0,
),
MaterialButton(
onPressed: () {
print(controller.text);
print("onpressed $userTask");
if (userTask == null) {
} else {
controller.clear();
Provider.of<TaskData>(context, listen: false)
.addTask(userTask);
print(TaskData().taskCount);
Navigator.pop(context);
}
},
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Text(
'ADD',
style: TextStyle(
fontSize: 22.0,
fontWeight: FontWeight.bold,
color: Colors.white),
),
),
color: Colors.lightBlueAccent,
),
],
),
),
);
}
}
List<Task> taskFromJson(String str) =>
List<Task>.from(json.decode(str).map((x) => Task.fromJson(x)));
String taskToJson(List<Task> data) =>
json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
class Task {
final String name;
bool isDone;
Task({this.name, this.isDone = false});
void toggleIsDone() {
isDone = !isDone;
}
factory Task.fromJson(Map<String, dynamic> json) => Task(
name: json["name"],
isDone: json["isDone"],
);
Map<String, dynamic> toJson() => {
"name": name,
"isDone": isDone,
};
}
class TaskData extends ChangeNotifier {
List<Task> _tasks = [];
UnmodifiableListView<Task> get tasks => UnmodifiableListView(_tasks);
int get taskCount => _tasks.length;
String _string;
String _bool;
void init() async {
SharedPreferences sPref = await SharedPreferences.getInstance();
String jsonTask = sPref.getString("task");
print(jsonTask);
if (jsonTask != null) {
_tasks = taskFromJson(jsonTask);
notifyListeners();
}
}
void saveToPreference() async {
SharedPreferences sPref = await SharedPreferences.getInstance();
sPref.setString("task", taskToJson(_tasks));
}
void addTask(String newTaskName) async {
final task = Task(name: newTaskName);
_tasks.add(task);
await saveToPreference();
notifyListeners();
}
void updateTask(Task task) async {
task.toggleIsDone();
await saveToPreference();
notifyListeners();
}
void removeTask(Task task) async {
_tasks.remove(task);
await saveToPreference();
notifyListeners();
}
}
class TaskScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.lightBlueAccent,
floatingActionButton: Padding(
padding: const EdgeInsets.only(bottom: 42.0, right: 36.0),
child: FloatingActionButton(
child: Icon(
Icons.add,
size: 48.0,
color: Colors.white,
),
backgroundColor: Colors.lightBlueAccent,
onPressed: () {
showModalBottomSheet(
context: context,
builder: (context) => AddTaskScreen(),
);
}),
),
body: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Container(
padding: EdgeInsets.only(
left: 50.0, top: 120.0, right: 30.0, bottom: 50.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
CircleAvatar(
child: Icon(
Icons.list,
color: Colors.lightBlueAccent,
size: 60.0,
),
backgroundColor: Colors.white,
radius: 40.0,
),
SizedBox(
height: 36.0,
),
Text(
'Todoey',
style: TextStyle(
color: Colors.white,
fontWeight: FontWeight.w800,
fontSize: 55.0,
),
),
SizedBox(
height: 4.0,
),
Padding(
padding: const EdgeInsets.only(left: 8.0),
child: Text(
'${Provider.of<TaskData>(context).taskCount} Tasks',
style: TextStyle(
color: Colors.white,
fontSize: 18.0,
),
),
),
],
),
),
Expanded(
child: Container(
//decoration: kContainerBoxRadius,
child: TaskList(),
),
),
]),
);
}
}
void main() {
runApp(MultiProvider(
providers: [
ChangeNotifierProvider(
create: (context) => TaskData()..init(),
),
],
child: MyApp(),
));
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
home: TaskScreen(),
);
}
}