HttpClient.GetAsync(…)使用等待/異步時(shí)永不返回我在.NET 4.5中使用System.Net.Http.HttpClient遇到了一些奇怪的行為，其中“等待”調(diào)用(例如)的結(jié)果。httpClient.GetAsync(...)再也不會(huì)回來(lái)了。這種情況只有在使用新的異步/等待語(yǔ)言功能和任務(wù)API時(shí)才會(huì)發(fā)生-當(dāng)只使用連續(xù)時(shí)，代碼似乎總是有效的。下面是一些再現(xiàn)問(wèn)題的代碼-將其放到VisualStudio 11中的一個(gè)新的“MVC 4 WebApi項(xiàng)目”中，以公開(kāi)以下GET端點(diǎn)：/api/test1/api/test2/api/test3/api/test4/api/test5 <--- never completes/api/test6這里的每個(gè)端點(diǎn)都返回相同的數(shù)據(jù)(stackoverflow.com中的響應(yīng)頭)，但/api/test5永遠(yuǎn)不會(huì)結(jié)束。我是否在HttpClient類中遇到了一個(gè)bug，或者我是否在某種程度上誤用了API？復(fù)制代碼：public class BaseApiController : ApiController{
/// <summary>
/// Retrieves data using continuations
/// </summary>
protected Task<string> Continuations_GetSomeDataAsync()
{
var httpClient = new HttpClient();
var t = httpClient.GetAsync("http://stackoverflow.com", HttpCompletionOption.ResponseHeadersRead);
return t.ContinueWith(t1 => t1.Result.Content.Headers.ToString());
}
/// <summary>
/// Retrieves data using async/await
/// </summary>
protected async Task<string> AsyncAwait_GetSomeDataAsync()
{
var httpClient = new HttpClient();
var result = await httpClient.GetAsync("http://stackoverflow.com", HttpCompletionOption.ResponseHeadersRead);
return result.Content.Headers.ToString();
}}public class Test1Controller : BaseApiController{
/// <summary>
/// Handles task using Async/Await
/// </summary>
public async Task<string> Get()
{
var data = await Continuations_GetSomeDataAsync();
return data;
}}public class Test2Controller : BaseApiController{
/// <summary>
/// Handles task by blocking the thread until the task completes
/// </summary>
public string Get()
{
var task = Continuations_GetSomeDataAsync();
var data = task.GetAwaiter().GetResult();
return data;
}}
HttpClient.GetAsync(…)使用等待/異步時(shí)永不返回
婷婷同學(xué)_
2019-07-08 15:08:44