Use Task Parallel Library - tasks running in parallel

　　This section describes the use of two methods, one is waiting for the group to perform all tasks are completed Task.WhenAll()method, as long as the other is a group perform the method has finished executing Task.WhenAny()the method.

Specific use, as shown demo code.

static void Main(string[] args)
{
    // first way to run through all the tasks waiting for completion Task.WhenAll 
    var firstTask = new new the Task < int > (() => TaskMethod ( " First the Task " , . 3 ));
     var SecondTask = new new the Task < int > (() => TaskMethod ( " Second the Task " , 2 ));

    // When whenAllTask performed only after the operation is completed SecondTask firstTask and the ContinueWith 
    var whenAllTask = Task.WhenAll (firstTask, SecondTask);
    whenAllTask.ContinueWith (T => the WriteLine ($ " first task answer {t.Result [0]}, the answer to the second task t.Result {[. 1]} " ), TaskContinuationOptions.OnlyOnRanToCompletion);

    firstTask.Start();
    secondTask.Start();

    Sleep(TimeSpan.FromSeconds(4));

    // Use WhenAny method as long as a task is completed list then the method will remove the task 
    var Tasks = new new List <the Task < int >> ();
     for ( int I = 0 ; I < . 4 ; I ++ )
    {
        int counter = 1;
        var task = new Task<int>(() => TaskMethod($"Task {counter}",counter));
        tasks.Add(task);
        task.Start();
    }

    while (tasks.Count > 0)
    {
        var completedTask = Task.WhenAny(tasks).Result;
        tasks.Remove(completedTask);
        The WriteLine ($ " a task has been completed, the result is completedTask.Result} { " );
    }

    ReadLine();
}

static int TaskMethod(string name, int seconds)
{
    The WriteLine ($ " task to run on {CurrentThread.ManagedThreadId} whether the thread pool thread:. CurrentThread.IsThreadPoolThread {} " );

    Sleep(TimeSpan.FromSeconds(seconds));
    return 42 * seconds;
}