WaitAll for multiple handles on a STA thread is not supported

Question

1. Why do I get this error message? \"WaitAll for multiple handles on a STA thread is not supported.\"
2. Should I use [MTAThreadAttribute] attribut? Update

Answer 1

use something like this:

foreach (ITask Task in Tasks)
{
    Task.WaitHandle = CompletedEvent;
    new Thread(Task.Run).Start();
}

int TasksCount = Tasks.Count;
for (int i = 0; i < TasksCount; i++)
    CompletedEvent.WaitOne();

if (AllCompleted != null)
    AllCompleted(this, EventArgs.Empty);