DateTime now = DateTime.Now;
DateTime dt = now.AddSeconds(1);
while(now<dt)
{
    now.AddSeconds(1);
}

------解决方案--------------------

VB.NET code

Public Sub Waiting(ByVal seconds As Integer)
    Dim tmpNow As Date = Now
    While Now.Subtract(tmpNow).Seconds < seconds
        Application.DoEvents()
    End While
End Sub