C＃-如何同时执行多个Web请求

Question

我编写了一个代码来检查URL，但是，ir的运行速度确实很慢。.我想尝试使其同时在几个URL上运行，例如10个URL，或者至少使其尽可能快。

我的代码：

Parallel.ForEach(urls, new ParallelOptions {
  MaxDegreeOfParallelism = 10
}, s => {
  try {
    using(HttpRequest httpRequest = new HttpRequest()) {
      httpRequest.UserAgent = "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Firefox/52.0";
      httpRequest.Cookies = new CookieDictionary(false);
      httpRequest.ConnectTimeout = 10000;
      httpRequest.ReadWriteTimeout = 10000;
      httpRequest.KeepAlive = true;
      httpRequest.IgnoreProtocolErrors = true;
      string check = httpRequest.Get(s + "'", null).ToString();
      if (errors.Any(new Func < string, bool > (check.Contains))) {
        Valid.Add(s);
        Console.WriteLine(s);
        File.WriteAllLines(Environment.CurrentDirectory + "/Good.txt", Valid);
      }
    }
  } catch {

  }
});

Answer 1

您的服务调用不太可能受CPU限制。因此，分配更多的线程来处理负载可能不是最好的方法-如果使用async，则会获得更好的吞吐量await，如果可以，则使用更现代的HttpClient而不是HttpRequest或HttpWebRequest。

这是一个如何做的例子：

var client = new HttpClient();

//Start with a list of URLs
var urls = new string[]
    {
        "http://www.google.com",
        "http://www.bing.com"
    };

//Start requests for all of them
var requests  = urls.Select
    (
        url => client.GetAsync(url)
    );

//Wait for all the requests to finish
await Task.WhenAll(requests);

//Get the responses
var responses = requests.Select
    (
        task => task.Result
    );

foreach (var r in responses)
{
    var s = await r.Content.ReadAsStringAsync();
    Console.WriteLine(r);
}