【发布时间】：2022-12-30 01:59:17
【问题描述】：
我正在做一个 flutter 项目来展示一个 Scrumboard，这是我第一次使用 flutter。我有一个 TextButton，按下时会打开一个对话框。该对话框是一种表单，您可以在其中编辑有关 Scrum 任务的详细信息。我发现了两个问题。 1. 问题是当我使用下拉菜单并选择一个值时。该值不会更新。 2. 假设我编辑了一个 Scrum 任务，并从下拉菜单中将状态从“待办事项”设置为“进行中”并提交，UI 不会将该任务对象移动到“进行中”列。
我希望我提供的代码足够了，否则请告诉我。
Scrumboardscreen.dart
TextButton(
child: Text('Change'),
onPressed: () {
showDialog(
context: context,
builder: ((context) {
return AlertDialog(
title: Text('Task Informations'),
content: Form(
key: _formKey,
child: Column(
children: [
Text('Task Name'),
TextFormField(
controller: textscontrollers[0],
decoration: InputDecoration(
hintText: data[listIndex]
.items[itemIndex]
.taskName,
),
validator: (text) {
if (text == null || text.isEmpty) {
return 'Task Name cant be empty';
}
return null;
},
),
Text('Task Description'),
TextFormField(
controller: textscontrollers[1],
decoration: InputDecoration(
hintText: data[listIndex]
.items[itemIndex]
.taskDescription,
),
validator: (text) {
if (text == null || text.isEmpty) {
return 'Task Description cant be empty';
}
return null;
},
),
Text('Story Points'),
TextFormField(
controller: textscontrollers[2],
decoration: InputDecoration(
hintText: data[listIndex]
.items[itemIndex]
.storyPoints
.toString(),
),
validator: (text) {
if (text == null || text.isEmpty) {
return 'Story Points cant be empty';
}
return null;
},
),
Text('Task State'),
DropdownButton<String>(
value: data[listIndex]
.items[itemIndex]
.taskState,
icon: const Icon(Icons.arrow_downward),
elevation: 16,
style: const TextStyle(
color: Colors.blue,
),
underline: Container(
height: 2,
color: Colors.blue,
),
onChanged: (String? value) {
setState(() {
data[listIndex]
.items[itemIndex]
.taskState = value!;
});
},
items: states
.map<DropdownMenuItem<String>>(
(String value) {
return DropdownMenuItem<String>(
value: value,
child: Text(value),
);
}).toList(),
),
ElevatedButton(
onPressed: () {
if (_formKey.currentState!
.validate()) {
_UpdateTask(data[listIndex]
.items[itemIndex]);
ScaffoldMessenger.of(context)
.showSnackBar(const SnackBar(
content:
Text('Updated Task')));
Navigator.of(context).pop();
}
},
child: Text('Submit Changes'),
)
],
),
),
);
}));
},
),
此方法在 Futurebuilder 中，并在 UI 上显示数据
Future<List<BoardPostColumn>> GetData() async {
if (data.isEmpty) {
data = await manager.GetData();
}
return data;
}
更新方法
void _UpdateTask(BoardPost task) async {
task.taskName = textscontrollers[0].text;
task.taskDescription = textscontrollers[1].text;
task.storyPoints = int.parse(textscontrollers[2].text);
BoardPost result = await manager.UpdateTask(task);
setState(() {
//My understanding that this would update the UI
task = result;
textscontrollers[0].clear();
textscontrollers[1].clear();
textscontrollers[2].clear();
});
}
经理班
Future<BoardPost> UpdateTask(BoardPost task) async {
return handler.UpdateTask(task);
}
ApiHandler.dart
Future<BoardPost> UpdateTask(BoardPost task) async {
Response response = await post(
Uri.parse('https://localhost:7252/api/ScrumTask/UpdateScrumTask'),
headers: <String, String>{
'Content-Type': 'application/json; charset=UTF-8',
},
body: jsonEncode(<String, dynamic>{
'id': task.id,
'taskName': task.taskName,
'taskDescription': task.taskDescription,
'storyPoints': task.storyPoints,
'taskState': task.taskState
}));
if (response.statusCode == 200) {
Map<String, dynamic> ScrumMap = jsonDecode(response.body);
return BoardPost.fromJson(ScrumMap);
} else {
throw Exception('Failed to Update');
}
}
class BoardPost {
int? id;
String? taskName;
String? taskDescription;
int? storyPoints;
String? taskState;
BoardPost(
{this.id,
this.taskName,
this.taskDescription,
this.storyPoints,
this.taskState});
BoardPost.fromJson(Map<String, dynamic> json) {
id = json['id'];
taskName = json['taskName'];
taskDescription = json['taskDescription'];
storyPoints = json['storyPoints'];
taskState = json['taskState'];
}
这里的这个类将显示所有数据
class BoardPostColumn {
String title;
List<BoardPost> items;
BoardPostColumn({
required this.title,
required this.items,
});
}
返回从 api 提供的数据的管理器类
Future<List<BoardPostColumn>> GetData() async {
Response responseBody = await handler.GetData();
List<BoardPostColumn> data = [];
List<BoardPost> tasks = (json.decode(responseBody.body) as List)
.map((data) => BoardPost.fromJson(data))
.toList();
data.add(BoardPostColumn(
title: 'To do',
items:
tasks.where((e) => e.taskState?.toLowerCase() == 'todo').toList()));
data.add(BoardPostColumn(
title: 'In Progress',
items: tasks
.where((e) => e.taskState?.toLowerCase() == 'in progress')
.toList()));
data.add(BoardPostColumn(
title: 'Done',
items:
tasks.where((e) => e.taskState?.toLowerCase() == 'done').toList()));
return data;
}
【问题讨论】：