How to determine if an exception is of a particular type

Replace System.Threading.ThreadAbortException with your exception.

try
{
    //assume ThreadAbortException occurs here
}
catch (Exception ex)
{
    if (ex.GetType().IsAssignableFrom(typeof(System.Threading.ThreadAbortException)))
    {
         //what you want to do when ThreadAbortException occurs         
    }
    else
    {
         //do when other exceptions occur
    }
}

before your current catch add the following:

catch(DbUpdateException ex)
{
  if(ex.InnerException is UpdateException)
  {
    // do what you want with ex.InnerException...
  }
}

From C# 6, you can do the following:

catch(DbUpdateException ex) when (ex.InnerException is UpdateException)
{
    // do what you want with ex.InnerException...
}