DataBand is used for lists building. The band repeatedly outputs elements embedded into it. Visual elements output as a list must be contained in the Detail inside DataBand. Detail sets row height. InstanceCount property sets the amount of repetitions.
<DataBand name>.LineNumber() statement is used for getting line number.
Example of a list that outputs line number in the list:
dataBand1.InstanceCount = 5;
textBox.Value = "line number = " + dataBand1.LineNumber().ToString() + " of " + dataBand1.InstanceCount.ToString();