grAxis objects in Graph controls
The minor grid for an axis extends from the tick marks on the axis across the data area of the graph. The minor grid lines fall between the tick marks and display when the number of divisions is two or greater.
The MinorGridLine property specifies the line style for the minor grid.
To set the line style for a minor grid line:
Display the Axis tab page of the graph control’s Properties view and select the desired axis from the Axis drop-down list.
Select the desired line style from the MinorGridLine drop-down list in the Minor Divisions group.
The MinorGridLine property takes a value of the LineStyle enumerated datatype.
This example specifies a dotted line for the minor grid line on the Value axis of Graph gr_1:
gr_1.Value.MinorGridLine = Dot!