/// <summary>
/// Creates a Task that represents the completion of another Task, and
/// that schedules an AsyncCallback to run upon completion.
/// </summary>
/// <param name="task">The antecedent Task.</param>
/// <param name="callback">The AsyncCallback to run.</param>
/// <param name="state">The object state to use with the AsyncCallback.</param>
/// <returns>The new task.</returns>
public static Task <TResult> ToAsync <TResult>(this Task <TResult> task, AsyncCallback callback, object state)
{
if (task == null)
{
throw new ArgumentNullException(nameof(task));
}
var tcs = new TaskCompletionSource <TResult>(state);
task.ContinueWith(_ =>
{
tcs.SetFromTask(task);
callback?.Invoke(tcs.Task);
});
return(tcs.Task);
}
/// <summary>
/// Creates a Task that represents the completion of another Task, and
/// that schedules an AsyncCallback to run upon completion.
/// </summary>
/// <param name="task">The antecedent Task.</param>
/// <param name="callback">The AsyncCallback to run.</param>
/// <param name="state">The object state to use with the AsyncCallback.</param>
/// <returns>The new task.</returns>
public static Task ToAsync(this Task task, AsyncCallback callback, object state)
{
Contract.Requires(task != null);
var tcs = new TaskCompletionSource <object>(state);
task.ContinueWith(_ =>
{
tcs.SetFromTask(task);
if (callback != null)
{
callback(tcs.Task);
}
});
return(tcs.Task);
}
/// <summary>
/// Creates a Task that represents the completion of another Task, and
/// that schedules an AsyncCallback to run upon completion.
/// </summary>
/// <param name="task">The antecedent Task.</param>
/// <param name="callback">The AsyncCallback to run.</param>
/// <param name="state">The object state to use with the AsyncCallback.</param>
/// <returns>The new task.</returns>
public static Task <TResult> ToAsync <TResult>(this Task <TResult> task, AsyncCallback callback, object state)
{
if (task == null)
{
throw new ArgumentNullException("task");
}
TaskCompletionSource <TResult> tcs = new TaskCompletionSource <TResult>(state);
task.ContinueWith(delegate(Task <TResult> _)
{
tcs.SetFromTask(task);
if (callback != null)
{
callback(tcs.Task);
}
});
return(tcs.Task);
}
/// <summary>
/// Creates a Task that represents the completion of another Task, and
/// that schedules an AsyncCallback to run upon completion.
/// </summary>
/// <param name="task">The antecedent Task.</param>
/// <param name="callback">The AsyncCallback to run.</param>
/// <param name="state">The object state to use with the AsyncCallback.</param>
/// <returns>The new task.</returns>
public static Task ToAsync(this Task task, AsyncCallback callback, object state)
{
if (task == null)
{
throw new ArgumentNullException("task");
}
var tcs = new TaskCompletionSource <object>(state);
task.ContinueWith(_ =>
{
tcs.SetFromTask(task);
if (callback != null)
{
callback(tcs.Task);
}
});
return(tcs.Task);
}
/// <summary>Transfers the result of a Task to the TaskCompletionSource.</summary>
/// <typeparam name="TResult">Specifies the type of the result.</typeparam>
/// <param name="resultSetter">The TaskCompletionSource.</param>
/// <param name="task">The task whose completion results should be transfered.</param>
public static void SetFromTask <TResult>(this TaskCompletionSource <TResult> resultSetter, Task <TResult> task)
{
resultSetter.SetFromTask <TResult>((Task)task);
}
