Следующий код создает задачу, которая отменяется. Выражение await (случай 1) генерирует System.OperationCanceledException, а синхронное Wait() (случай 2) генерирует System.Threading.Tasks.TaskCanceledException (завернутое в System.AggregateException< /код>).
using System;
using System.Threading;
using System.Threading.Tasks;
public class Program
{
public static void Main()
{
Program.MainAsync().Wait();
}
private static async Task MainAsync()
{
using(var cancellationTokenSource = new CancellationTokenSource())
{
var token = cancellationTokenSource.Token;
const int cancelationCheckTimeout = 100;
var task = Task.Run(
async () =>
{
for (var i = 0; i < 100; i++)
{
token.ThrowIfCancellationRequested();
Console.Write(".");
await Task.Delay(cancelationCheckTimeout);
}
},
cancellationTokenSource.Token
);
var cancelationDelay = 10 * cancelationCheckTimeout;
cancellationTokenSource.CancelAfter(cancelationDelay);
try
{
await task; // (1)
//task.Wait(); // (2)
}
catch(Exception ex)
{
Console.WriteLine(ex.ToString());
Console.WriteLine($"Task.IsCanceled: {task.IsCanceled}");
Console.WriteLine($"Task.IsFaulted: {task.IsFaulted}");
Console.WriteLine($"Task.Exception: {((task.Exception == null) ? "null" : task.Exception.ToString())}");
}
}
}
}
Вывод случая 1:
..........System.OperationCanceledException: The operation was canceled.
at System.Threading.CancellationToken.ThrowIfCancellationRequested()
at Program.c__DisplayClass1_0.d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Program.d__1.MoveNext()
Task.IsCanceled: True
Task.IsFaulted: False
Task.Exception: null
Вывод варианта 2:
..........System.AggregateException: One or more errors occurred. ---> System.Threading.Tasks.TaskCanceledException: A task was canceled.
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
at System.Threading.Tasks.Task.Wait()
at Program.d__1.MoveNext()
---> (Inner Exception #0) System.Threading.Tasks.TaskCanceledException: A task was canceled. System.Threading.Tasks.TaskCanceledException: A task was canceled.
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
at System.Threading.Tasks.Task.Wait()
at Program.d__1.MoveNext()
---> (Inner Exception #0) System.Threading.Tasks.TaskCanceledException: A task was canceled.
Подробнее здесь: https://stackoverflow.com/questions/343 ... s-canceled
