开火就忘了？

Question

I have a asyncRelayCommand in a c# wpf mvvm application that does not work i kinda understand that i need a method for this but the guide i went through does not mention how to make one https://johnthiriet.com/mvvm-going-async -with-async-command/这是我经历的指南，这是我的代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel.Dispatcher;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using GalaSoft.MvvmLight;

namespace DataConverter.Command
{

    public interface IAsyncCommand<T> : ICommand
    {
        Task ExecuteAsync(T parameter);
        bool CanExecute(T parameter);
    }

    public class AsyncCommand<T> : IAsyncCommand<T>
    {
        public event EventHandler CanExecuteChanged;

        private bool _isExecuting;
        private readonly Func<T, Task> _execute;
        private readonly Func<T, bool> _canExecute;
        private readonly IErrorHandler _errorHandler;

        public AsyncCommand(Func<T, Task> execute, Func<T, bool> canExecute = null, IErrorHandler errorHandler = null)
        {
            _execute = execute;
            _canExecute = canExecute;
            _errorHandler = errorHandler;
        }

        public bool CanExecute(T parameter)
        {
            return !_isExecuting && (_canExecute?.Invoke(parameter) ?? true);
        }

        public async Task ExecuteAsync(T parameter)
        {
            if (CanExecute(parameter))
            {
                try
                {
                    _isExecuting = true;
                    await _execute(parameter);
                }
                finally
                {
                    _isExecuting = false;
                }
            }

            RaiseCanExecuteChanged();
        }

        public void RaiseCanExecuteChanged()
        {
            CanExecuteChanged?.Invoke(this, EventArgs.Empty);
        }

        #region Explicit implementations
        bool ICommand.CanExecute(object parameter)
        {
            return CanExecute((T)parameter);
        }

        void ICommand.Execute(object parameter)
        {
            ExecuteAsync((T)parameter).FireAndForgetSafeAsync(_errorHandler);
        }
        #endregion
    }
}

谁能告诉我如何制作一个，这样就可以了，我真的不明白为什么指南没有提到它，但是是的

Answer 1

真正快速的 goole 搜索： https://www.google.de/search?q=FireAndForgetSafeAsync

=> https://johnthiriet.com/removing-async-void/

public static class TaskUtilities
{

    public static async void FireAndForgetSafeAsync(this Task task, IErrorHandler handler = null)
    {
       try
       {
           await task;
       }
       catch (Exception ex)
       {
           handler?.HandleError(ex);
       }
   }
}