This will only get you pointed in the right direction, but the general idea is to create a class that inherits NationalInstruments.UI.DateTimeFormatMode - something like this:
public class SecondsEditRangeFormat : DateTimeFormatMode
{
public override string FormatValue(object context, DateTimeFormatModeArgs args)
{
return args.Value.ToString("s.fff");
}
public override bool TryParse(string s, out DateTime value)
{
value = DateTime.ParseExact(s, "s.fff", CultureInfo.CurrentCulture);
return true;
}
}
and then assign an instance of your class to that property:
digitalWaveformGraph1.XAxis.EditRangeDateTimeFormatMode = new SecondsEditRangeFormat();