Flutter：此運算式的型別為“void”，因此無法使用其值

我正在嘗試呼叫deleteToDo()，并且editToDo()兩者都洗掉或編輯待辦事項串列中的專案。我正在使用可滑動的顫振 pub 來格式化待辦事項串列。但是，此錯誤顯示“此運算式的型別為 'void'，因此無法使用其值。還要檢查也可能為 void 的型別引數和變數。”

我嘗試將其編輯為，Future <Void>但隨后也出現以下錯誤：非常感謝任何幫助。

我的飛鏢檔案：

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:flutter_slidable/flutter_slidable.dart';
import 'package:best_before/ShoppingList/toDoClass.dart';
import 'package:best_before/ShoppingList/toDos.dart';
import 'package:best_before/ShoppingList/Utils.dart';

class ToDoWidget extends StatelessWidget {
  final ToDo toDo;

  const ToDoWidget({
    required this.toDo,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) => ClipRRect(
        borderRadius: BorderRadius.circular(16),
        child: Slidable(
          key: Key(toDo.id),
          startActionPane: ActionPane(
            motion:  ScrollMotion(),
            dismissible: DismissiblePane(onDismissed: () {}),
            children:  [
              SlidableAction(
                onPressed: deleteToDo(context,toDo),
                backgroundColor: Color(0xFFFE4A49),
                foregroundColor: Colors.white,
                icon: Icons.delete,
                label: 'Delete',
              ),
            ],
        
          ),
          endActionPane: ActionPane(
          motion: ScrollMotion(),
          children: [
           SlidableAction(
             flex: 2,
             onPressed: editToDo(context, toDo),
              backgroundColor: Colors.green,
              foregroundColor: Colors.white,
              icon: Icons.edit,
              label:'Edit'
            )
          ],
          ),
         child:buildTodo(context),
        ),
      );


  Widget buildTodo(BuildContext context) => GestureDetector(
    onTap: () => editToDo(context, toDo),
    child: Container(
        color: Colors.white,
        padding: EdgeInsets.all(20),
        child: Row(
          children: [
            Checkbox(
              activeColor: Theme.of(context).primaryColor,
              checkColor: Colors.white,
              value: toDo.isDone,
              onChanged: (_) { 
                final provider =
                      Provider.of<TodosProvider>(context, listen: false);
                  final isDone = provider.toggleTodoStatus(toDo);

                  Utils.showSnackBar(
                    context,
                    isDone ? 'Task completed' : 'Task marked incomplete',
                  );},
            ),
            const SizedBox(width: 20),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    toDo.title,
                    style: TextStyle(
                      fontWeight: FontWeight.bold,
                      color: Theme.of(context).primaryColor,
                      fontSize: 22,
                    ),
                  ),
                  if (toDo.description.isNotEmpty)
                    Container(
                      margin: EdgeInsets.only(top: 4),
                      child: Text(
                        toDo.description,
                        style: TextStyle(fontSize: 20, height: 1.5),
                      ),
                    )
                ],
              ),
            ),
          ],
        ),
      ));
}

  Void deleteToDo(BuildContext context, ToDo todo) {
    final provider = Provider.of<TodosProvider>(context, listen: false);
    provider.removeTodo(todo);

    Utils.showSnackBar(context, 'Deleted the task');
  }

 Void editToDo(BuildContext context, ToDo todo) => Navigator.of(context).push(
        MaterialPageRoute(
          builder: (context) => editToDoPage(Todo: todo),
        ),
      );

uj5u.com熱心網友回復：

嘗試這個：

SlidableAction(
   onPressed: (context) => deleteToDo(context,toDo),
   backgroundColor: Color(0xFFFE4A49),
   foregroundColor: Colors.white,
   icon: Icons.delete,
   label: 'Delete',
)

標籤：扑 镖

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