C#

public void AddTask(Task task) 
{ 
	tasks.Add(task); // tasks is a List<Task> object
	counterText = counterTemplate.Replace("#2", tasks.Count.ToString());
	task.BackgroundWorker.WorkerReportsProgress = true;
	task.BackgroundWorker.ProgressChanged += OnTaskProgressChanged;
	task.BackgroundWorker.RunWorkerCompleted += OnTaskCompleted;
}

void OnTaskCompleted(object sender, RunWorkerCompletedEventArgs e)
{
	tasks[currentIndex].InvalidateWorker(); // break point on this line
	NextTask();
}

public void InvalidateWorker()
{
	BackgroundWorker = null;
}

namespace BackgroundWorkerTest
{
	public partial class Form1 : Form
	{
		public Form1()
		{
			InitializeComponent();
		}

		private void OnDoWork(object sender, EventArgs e)
		{
			backgroundWorker.RunWorkerAsync();
			backgroundWorker.DoWork += backgroundWorker_DoWork;
		}

		void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
		{
			for (int i = 0; i < 10; ++i)
			{
				for (int x = 0; x < 10; ++x)
				{
					for (int j = 0; j < 1000000; ++j)
					{
						bool b = false;
					}
				}
				backgroundWorker.ReportProgress(500);
			}
			//backgroundWorker.
		}

		private void OnProgressChanged(object sender, ProgressChangedEventArgs e)
		{
			progressBar1.Value += e.ProgressPercentage;
		}

		private void OnWorkComplete(object sender, RunWorkerCompletedEventArgs e)
		{
			MessageBox.Show("Worker Done!", "Worker Message");
		}
	}
}

public interface IDoWork {

     void DoWork( object sender, DoWorkEventArgs e );
     void ProgressChanged( object sender, ProgressChangedEventArgs e );
     void WorkerCompleted( object sender, RunWorkerCompletedEventArgs e );

  }  // end interface.

Member 12898590 wrote:

by using what field to update automatically the student promotion

string input = "2017-09-19T08:04:31.123";

DateTime parsedDate;
bool isValid = DateTime.TryParseExact(input, 
    "yyyy-MM-ddThh:mm:ss.fff", 
    CultureInfo.InvariantCulture, 
    DateTimeStyles.AssumeUniversal, 
    out parsedDate);

/*
isValid: true
parsedDate: 2017-09-19 09:04:31.123 UTC
*/

DateTime dt = DateTime.ParseExact(input, "yyyy-MM-dd hh:mm:ss.fff", CultureInfo.InvariantCulture);