重新分解异步获取api请求不等待数据。 [英] Re-factored async get api request not awaiting data.

问题描述

你好我/女孩我有点问题。我有一个执行get请求的方法。这种方法有效。所以我重新考虑了这个方法，以便某些部分可以用于其他方法。

Hello guys/girls i am having a bit of problem. i have a method that performs a get request. this method works. so i re-factored the method, so that certain parts can be used for other methods.

//Original Method
public async Task<T> GetByIdAsync(T returnType, T1 controllerName, T2 Id)
{
  var url = baseUrl + controllerName + "/" + Id;
  var result = returnType;
  using (HttpClient client = new HttpClient())
  {
     client.BaseAddress = new Uri(url);
     client.DefaultRequestHeaders.Accept.Clear();
     client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

      var response = await client.GetAsync(url);
      if (response.IsSuccessStatusCode)
      {
         var data = response.Content.ReadAsStringAsync();
          result = JsonConvert.DeserializeObject(data.Result);
       }
    }
}


//refactored method        
public async Task<T> GetByIdAsync<T, T1, T2>(T returnType, T1 controllerName, T2 Id)
{
    var url = baseUrl + controllerName + "/" + Id;
    var result = returnType;
    var client = GetClient(url);

    var response = await client.GetAsync(url);
    if (response.IsSuccessStatusCode)
    {
        var data = response.Content.ReadAsStringAsync();
        result = JsonConvert.DeserializeObject<T>(data.Result);
    }
    return result;
}

public static HttpClient GetClient(string url)
{
    using (HttpClient client = new HttpClient())
    {
        client.BaseAddress = new Uri(url);
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

        return client;
    }
}

重新计算方法后，它不再等待。怎么了 ？ 。



我的尝试：



原始代码有效，我试图理解为什么重新分解的代码不起作用

After i re-factored the method, it no longer awaits. what is wrong ? .

What I have tried:

the original code works, i am trying to understand why the re-factored code doesn't work

推荐答案

使用在对象离开使用上下文时处理（销毁）对象，所以你的HttpClient在GetClient方法之外不可用。删除使用

"using" disposes (destroys) an object when it leaves the using context, so your HttpClient is not usable outside of the GetClient method. Remove the "using"

public static HttpClient GetClient(string url)
{
    HttpClient client = new HttpClient();
    client.BaseAddress = new Uri(url);
    client.DefaultRequestHeaders.Accept.Clear();
    client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
 
    return client;
}

这篇关于重新分解异步获取api请求不等待数据。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！