private void OnScrollBarScroll(object sender, ScrollEventArgs e)
{
Console.WriteLine("scrollvalue:{0} min:{1} max:{2}", e.NewValue, this.scrollBar.Minimum, this.scrollBar.Maximum);
if (this.scrollBar.Value == e.NewValue)
return;
int delta = e.NewValue - this.scrollBar.Value;
SetIndexInterval(this.firstIndex + delta, this.lastIndex + delta);
Invalidate();
}
#endif