C#

private async void AddUser()
{
    UserEntity user = new UserEntity
    {
        FirstName = "Jack",
        LastName = "Stone",
        UserName = "jstone",
        Password = ""
    };

    await Task.Factory.StartNew(() =>
    {
        IBizObj bo = new BizObj(connString);
        bo.AddUser(user);

    }).ContinueWith(task =>
    {
        UserList.Add(user);
    });
}

public class BizObj : IBizObj
{
    IRepository _repoisitory;

<pre>
public BizObj(string connectionString)
{
    _repoisitory = new FalconRepository(connectionString);
}

public int AddUser(UserEntity entity)
{
    return _repoisitory.AddUser(entity);
}

public int AddUser(UserEntity entity)
{
    using (var dc = GetDataContext())
    {
        int results = 0;

        try
        {
            User user = new User
            {
                FirstName = entity.FirstName,
                LastName = entity.LastName,
                UserName = entity.UserName,
                Password = entity.Password,
                CanLogIn = entity.CanLogIn,
                PasswordChangeDate = entity.PasswordChangeDate,
                CreatedByUserId = 1,
                CreatedDT = DateTime.Now,
            };

            dc.Users.InsertOnSubmit(user);
            dc.SubmitChanges();

            results = user.Id;
        }
        catch (Exception e)
        {
             //<===================================== HANDLE EXCEPTION HERE
        }

        return results;
    }
}

var d0 = new DateTime(2019, 10, 20);
var d1 = new DateTime(2018, 10, 20);
var d2 = new DateTime(2019, 10, 21);
var d3 = new DateTime(2019, 10, 20);
var d4 = new DateTime(2017, 10, 21);
var d5 = new DateTime(2013, 10, 22);
var d6 = new DateTime(2015, 10, 21);
var d7 = new DateTime(2010, 10, 23);
var d8 = new DateTime(1995, 10, 20);
var d9 = new DateTime(2019, 10, 22);

var list = new List<(DateTime Date, string Name)>();
list.Add((d0, "D0"));
list.Add((d1, "D1"));
list.Add((d2, "D2"));
list.Add((d3, "D3"));
list.Add((d4, "D4"));
list.Add((d5, "D5"));
list.Add((d6, "D6"));
list.Add((d7, "D7"));
list.Add((d8, "D8"));
list.Add((d9, "D9"));

(2019-10-20, "D0")
(2018-10-20, "D1")
(2019-10-20, "D3")
(1995-10-20, "D8")
(2019-10-21, "D2")
(2017-10-21, "D4")
(2015-10-21, "D6")
(2013-10-22, "D5")
(2019-10-22, "D9")
(2010-10-23, "D7")

private void showTooltip(Control position, string Title, string Message)
{
    ToolTip t = new ToolTip();
    try
    {

        t.UseFading = true;
        t.UseAnimation = true;
        t.IsBalloon = true;
        t.ShowAlways = true;
        t.AutoPopDelay = 5000;
        t.InitialDelay = 500;
        t.ReshowDelay = 500;
        t.ToolTipTitle = Title;
        t.RemoveAll();
        t.SetToolTip(position, Message);
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message.ToString());
    }
}

public interface IValueWithUnit {...}
[Serializable]
public struct DoubleValueWithUnit : IValueWithUnit { ... }

string name = "DoubleValueWithUnit";
Type t;
if (TypeHelper.TryFindType(name, out t))
{
    m_IsValueWithUnit = t.IsSubclassOf(typeof(IValueWithUnit)); // false
    m_IsValueWithUnit = t.IsSubclassOf(typeof(DoubleValueWithUnit)); // false
    m_IsValueWithUnit = t.IsInstanceOfType(typeof(IValueWithUnit)); // false
    m_IsValueWithUnit = t.IsInstanceOfType(typeof(DoubleValueWithUnit)); // false
    m_IsValueWithUnit = t.IsAssignableFrom(typeof(IValueWithUnit)); // false
    m_IsValueWithUnit = t.IsAssignableFrom(typeof(DoubleValueWithUnit)); // true
    m_IsValueWithUnit = t.GetInterface(nameof(IValueWithUnit)) != null; // true