C#

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

private void button2_Click(object sender, EventArgs e)
{
  for(int i = 0; i < checkedListBox1.CheckedItems.Count; i++)
  {
   if (!listBox1.Items.Contains(checkedListBox1.CheckedItems[i]))
   {
                    listBox1.Items.Add(checkedListBox1.CheckedItems[i]);

                    newPanel.Name = "panel " + (i+2).ToString();
                    newPanel.Location = new Point(405, 10);
                    newPanel.Parent = this;
                    newPanel.Size = new Size(341, 333);
                    newPanel.Visible = false;
                    newPanel.Controls.Add(nameLabel);
                    newPanel.Controls.Add(testButton);
                    listPanel.Add(newPanel);
                    newPanel.Show();
      }
   }
}

private void listBox1_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            int index = this.listBox1.IndexFromPoint(e.Location);

            if(index != System.Windows.Forms.ListBox.NoMatches)
            {
                if(index < listPanel.Count - 1)
                {
                    //nameLabel.Text = "panel " + listPanel[index++].ToString();
                    listPanel[index++].Visible = true;
                    MessageBox.Show("" + listPanel.Count.ToString());
                    listPanel[--index].Show();

                }
            }
        }