CAD tip # 12075:

An example - show message for 3 seconds:

Imports System.Threading.Tasks

Dim timeout = 3 ' secs
Dim msg As New Form() With { .Enabled = False }
Task.Delay(TimeSpan.FromSeconds(timeout)).ContinueWith(
  Sub(t) 
    msg.Close() 
  End Sub ,
TaskScheduler.FromCurrentSynchronizationContext())
MessageBox.Show(msg, "My temporary message", "MyTitle")