异步一次性创建

你可以这样做。我仍然不确定这是一个多么好的主意:

public class DisposableAsync
{
    private readonly IDisposable _disposable; 
    private readonly Func<Task> _asyncDisposalAction;
    public DisposableAsync(IDisposable disposable, Func<Task> asyncDisposalAction)
    {
        _disposable = disposable;
        _asyncDisposalAction = asyncDisposalAction;
    }

    public Task DisposeAsync()
    {
        _disposable.Dispose();
        return _asyncDisposalAction();
    }
}

public static class DisposableAsyncExtensions
{
    public static DisposableAsync ToAsync(this IDisposable disposable, Func<Task> asyncDisposalAction)
    {
        return new DisposableAsync(disposable, asyncDisposalAction);
    }
}

然后你可以这样使用它:

async Task Go()
{

    var o = Observable.Interval(TimeSpan.FromMilliseconds(100));
    var d = o
        .Subscribe(i => Console.WriteLine($"{DateTime.Now.ToLongTimeString()}: {i}"))
        .ToAsync(async () =>
        {
            Console.WriteLine($"{DateTime.Now.ToLongTimeString()}: Dispose Beginning");
            await Task.Delay(1000);
            Console.WriteLine($"{DateTime.Now.ToLongTimeString()}: Dispose Complete");
        });
    Console.Read();
    var t = d.DisposeAsync();
    Console.WriteLine($"{DateTime.Now.ToLongTimeString()}: Outside task, waiting for dispose to complete");
    await t;
    Console.WriteLine($"{DateTime.Now.ToLongTimeString()}: Task Complete");

}

此解决方案不适用于 using() 语句和类 DisposableAsync

我不认为 async () => 有你认为的问题。

试试这个:

Action x = async () =>
{
    try
    {
        Console.WriteLine("Hello");
        await Task.Delay(TimeSpan.FromSeconds(2.0));
        throw new Exception("Wait");
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
    Console.WriteLine("Goodbye");
};

var d = Disposable.Create(x);

d.Dispose();

Hello
Wait
Goodbye