在PCL异步调用与HttpClient的 [英] Async call with HttpClient in PCL

问题描述

我了PCL中，我想打一个异步调用usingg HttpClient的。 I codeD这样的

I have a PCl in which I want to make a async call usingg HttpClient. I coded like this

 public static async Task<string> GetRequest(string url)
    {            
        var httpClient = new HttpClient() { MaxResponseContentBufferSize = int.MaxValue };
        HttpResponseMessage response = await httpClient.GetAsync(url);
        return response.Content.ReadAsStringAsync().Result;
    }

不过，伺机正显示出错误无法等待System.net.http.htt presponsemessage之类的消息。

But await is showing error "cannot await System.net.http.httpresponsemessage" like message.

如果我用code这样比一切顺利，但不是在异步方式

If I use code like this than everything goes well but not in async way

public static string GetRequest(string url)
    {
        var httpClient = new HttpClient() { MaxResponseContentBufferSize = int.MaxValue };
        HttpResponseMessage response = httpClient.GetAsync(url).Result;
        return response.Content.ReadAsStringAsync().Result;
    }

我只是想，这种方法在异步的方式执行。任何帮助，请。

I just want that this method executes in async way. Any help please.

这是屏幕截图。

This is the screen shot.

推荐答案

按照 TAP准则，不要忘了叫 EnsureSuccessStatus code ，配置你的资源，并更换所有的结果 s的的await 取值：

Follow the TAP guidelines, don't forget to call EnsureSuccessStatusCode, dispose your resources, and replace all Results with awaits:

public static async Task<string> GetRequestAsync(string url)
{            
  using (var httpClient = new HttpClient() { MaxResponseContentBufferSize = int.MaxValue })
  {
    HttpResponseMessage response = await httpClient.GetAsync(url);
    response.EnsureSuccessStatusCode();
    return await response.Content.ReadAsStringAsync();
  }
}

如果您code不需要做别的，的HttpClient 有一个 GetStringAsync 方法这是否为您：

If your code doesn't need to do anything else, HttpClient has a GetStringAsync method that does this for you:

public static async Task<string> GetRequestAsync(string url)
{            
  using (var httpClient = new HttpClient() { MaxResponseContentBufferSize = int.MaxValue })
    return await httpClient.GetStringAsync(url);
}

如果您共享的HttpClient 情况下，这可以简化为：

If you share your HttpClient instances, this can simplify to:

private static readonly HttpClient httpClient =
    new HttpClient() { MaxResponseContentBufferSize = int.MaxValue };
public static Task<string> GetRequestAsync(string url)
{            
  return httpClient.GetStringAsync(url);
}

这篇关于在PCL异步调用与HttpClient的的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！