c# - 将 Func 委托(delegate)与 Async 方法结合使用

Question

我正在尝试将 Func 与异步方法结合使用。我收到一个错误。

Cannot convert async lambda expression to delegate type 'Func<HttpResponseMesage>'. An async lambda expression may return void, Task or Task<T>, none of which are convertible to 'Func<HttpResponseMesage>'.

下面是我的代码:

public async Task<HttpResponseMessage> CallAsyncMethod()
{
    Console.WriteLine("Calling Youtube");
    HttpClient client = new HttpClient();
    var response = await client.GetAsync("https://www.youtube.com/watch?v=_OBlgSz8sSM");
    Console.WriteLine("Got Response from youtube");
    return response;
}

static void Main(string[] args)
{
    Program p = new Program();
    Task<HttpResponseMessage> myTask = p.CallAsyncMethod();
    Func<HttpResponseMessage> myFun =async () => await myTask;
    Console.ReadLine();
}

Answer 1

如错误所述，异步方法返回 Task , Task<T>或 void .因此，要使其正常工作，您可以:

Func<Task<HttpResponseMessage>> myFun = async () => await myTask;