Question

我正在尝试上班。它适用于邮差，但它不适用于我的应用程序。它似乎达到了超时。

jbx.sellos.com.br/v1/auth

我正在使用此代码：

public async void GetToken(string strUserName, string strPassword)
{
    var client = new HttpClient();
    object userInfo = new { username = "root", password = "toor" };

    var jsonObj = JsonConvert.SerializeObject(userInfo);

    var content = new StringContent(jsonObj, Encoding.UTF8, "application/json");

    HttpResponseMessage response = client.PostAsync(RequestUri(), content).Result;

    var result = await response.Content.ReadAsStringAsync();
}

这是我尝试过的另一个代码：

public async Task<bool> Test()
{
    HttpClient client = new HttpClient();

    object userInfo = new { username = "root", password = "toor" };

    var jsonObj = JsonConvert.SerializeObject(userInfo);

    var content = new StringContent(jsonObj, Encoding.UTF8, "application/json");

    try
    {
        HttpResponseMessage response = await client.PostAsync(RequestUri(), content);

        var result = await response.Content.ReadAsStringAsync();

        if (response.IsSuccessStatusCode)
        {
            return true;
        }

        return false;
    }
    catch (Exception e)
    {
        return false;
    }
}

在所有情况下，代码运行到HttpResponseMessage response = await client.PostAsync(RequestUri(), content);之后，应用程序继续运行但过了一会儿我收到一条消息“应用程序处于中断模式”。

因此，在深入挖掘之后，我能够捕获异常：

{System.Threading.Tasks.TaskCanceledException: A task was canceled.
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00026] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Net.Http.HttpClientHandler+<SendAsync>d__63.MoveNext () [0x004c6] in <b696532a7c264e5e866cb15a1b40a4a4>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x0001a] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Net.Http.HttpClient+<SendAsyncWorker>d__49.MoveNext () [0x000ca] in <b696532a7c264e5e866cb15a1b40a4a4>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x0001a] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in <3fd174ff54b146228c505f23cf75ce71>:0 
  at AppX.WebServiceCalls+<SendRequestAsync>d__3.MoveNext () [0x000ba] in C:\Users\Bruno\documents\visual studio 2017\Projects\AppX\AppX\AppX\clWebServiceCalls.cs:123 }

我发现这些人谈论类似的东西： https://github.com/dotnet/corefx/issues/25800

到目前为止，还没有找到解决方案的线索。

Answer 1

由于

，您似乎陷入僵局

case class obja = (a_id: String, a_type: String)
case class objb = (b_id: String, b_type: String, b_name: String)
case class objc = (c_id: String, c_type: String, c_name: String)
val lista: List[obja] = List(...)
val listb: List[objb] = List(...)

def getNames(alist: List[obja], blist: List[objb]): List[objc] = ???

您应该将def r(x: Int, y: Int): Int = if (x==y) x else if (x>y) r(x-y, y) else r(x, y-x)用于异步方法。所以，修改那一行;

HttpResponseMessage response = client.PostAsync(RequestUri(), content).Result;

Answer 2

解决方案： var client = new HttpClient(new NativeMessageHandler());

这是我必须更改的所有代码new NativeMessageHandler()。

我还在我的解决方案中添加了一个包。搜索“modernhttpclient”。

感谢大家的帮助。

如何在xamarin上发出HTTP POST Web请求？

2 个答案: