Question

代码如下。

我想异步调用DoLongWork函数。

但是代码最终是同步的，因为DoLongWork不会等待任何事情。

DoLongWork功能无需等待。因为功能本身长期运行。不等任何资源。

如何摆脱这种恶性循环？

 class Program
    {
        static void Main(string[] args)
        {
            Task<int> task = Foo("Something");
            Console.WriteLine("Do it");
            Console.WriteLine("Do that");
            task.Wait();
            Console.WriteLine("Ending All");
        }
        static async Task<int> Foo(string param)
        {
            Task<int> lwAsync = DoLongWork(param);
            int res = await lwAsync;
            return res;
        }

        static async Task<int> DoLongWork(string param)
        {
            Console.WriteLine("Long Running Work is starting");
            Thread.Sleep(3000); // Simulating long work.
            Console.WriteLine("Long Running Work is ending");
            return 0;
        }
    }

Answer 1

您可以使用Task.Run在后台线程上执行同步工作：

// naturally synchronous, so don't use "async"
static int DoLongWork(string param)
{
    Console.WriteLine("Long Running Work is starting");
    Thread.Sleep(3000); // Simulating long work.
    Console.WriteLine("Long Running Work is ending");
    return 0;
}

static async Task<int> FooAsync(string param)
{
    Task<int> lwAsync = Task.Run(() => DoLongWork(param));
    int res = await lwAsync;
    return res;
}

Async / Await - Vicious Circle C＃5.0

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