如何在并行运行时获得HttpClient响应时间

Question

在我的ASP.NET MVC4应用程序中,我有一个控制器操作,我可以在其中访问多个外部网站并收集我在页面上以聚合方式显示的信息.显然,我想并行执行此操作,因此我编写了类似于此的代码:

var client1 = new HttpClient().GetAsync("http://google.com");
var client2 = new HttpClient().GetAsync("http://stackoverflow.com");
var client3 = new HttpClient().GetAsync("http://twitter.com");

var result1 = client1.Result;
var result2 = client2.Result;
var result3 = client3.Result;

如何找出每个请求完成的时间,以便我可以在我的页面上显示该信息？

Answer 1

我可能会尝试类似以下内容:

private async void _HttpServerDemo()
{
    var info1 = _GetHttpWithTimingInfo("http://google.com");
    var info2 = _GetHttpWithTimingInfo("http://stackoverflow.com");
    var info3 = _GetHttpWithTimingInfo("http://twitter.com");

    await Task.WhenAll(info1, info2, info3);
    Console.WriteLine("Request1 took {0}", info1.Result);
    Console.WriteLine("Request2 took {0}", info2.Result);
    Console.WriteLine("Request3 took {0}", info3.Result);
}

private async Task<Tuple<HttpResponseMessage, TimeSpan>> _GetHttpWithTimingInfo(string url)
{
    var stopWatch = Stopwatch.StartNew();
    using (var client = new HttpClient())
    {
        var result = await client.GetAsync(url);
        return new Tuple<HttpResponseMessage, TimeSpan>(result, stopWatch.Elapsed);
    }
}