feat:更新待办事项对话框功能

lib/models/todo.dart

@@ -1,45 +1,48 @@
 import 'package:flutter/material.dart';
 
 class TodoItem {
-  String id;
+  num id;
   String title;
-  String? description;
+  String content;
   bool isCompleted;
-  DateTime createdAt;
   DateTime? dueDate;
   TodoPriority priority;
-  String? category;
 
   TodoItem({
     required this.id,
     required this.title,
-    this.description,
+    required this.content,
     this.isCompleted = false,
-    DateTime? createdAt,
     this.dueDate,
     this.priority = TodoPriority.medium,
-    this.category,
-  }) : createdAt = createdAt ?? DateTime.now();
+  });
 
   TodoItem copyWith({
-    String? id,
+    num? id,
     String? title,
-    String? description,
+    String? content,
     bool? isCompleted,
-    DateTime? createdAt,
     DateTime? dueDate,
     TodoPriority? priority,
-    String? category,
   }) {
     return TodoItem(
       id: id ?? this.id,
       title: title ?? this.title,
-      description: description ?? this.description,
+      content: content ?? this.content,
       isCompleted: isCompleted ?? this.isCompleted,
-      createdAt: createdAt ?? this.createdAt,
       dueDate: dueDate ?? this.dueDate,
       priority: priority ?? this.priority,
-      category: category ?? this.category,
+    );
+  }
+
+  static TodoItem getEmpty() {
+    return TodoItem(
+        id: 0,
+        title: '',
+        content: '',
+        isCompleted: false,
+        dueDate: null,
+        priority: TodoPriority.medium,
     );
   }
 }