What does the toprowindex in gridview do?

GridView.TopRowIndex - scrolls a View up or down to a row with the required visible index. The GridView.RowCount property returns the number of records that are currently visible in the view. When the number changes, the BaseView.RowCountChanged event fires.
In this manner, how to use toprowindex member in grid control?
The TopRowIndex member can only be used with real Views that are displayed within the Grid Control. The real Views with which an end-user interacts at runtime can be accessed using the following methods. GridView.GetDetailView - returns a detail clone View for a specific master row.
Keeping this in consideration, how is the gridviewrow class used in webcontrols? The GridViewRow class is used represent an individual row in a GridView control. Each row in the GridView control has a designated row type using the DataControlRowType enumeration. The following table lists the different row types.
Furthermore, how to determine the index of a gridviewrow object?
To determine the index of a GridViewRow object in the Rows collection, use the RowIndex property. You can access the properties of the underlying data object that is bound to the GridViewRow object by using the DataItem property.
Similarly, how to make a row visible in a GridView?
Note that if the GridOptionsBehavior.SmartVertScrollBar option is disabled, any row within the View can be made top visible. For instance, you can assign the last visible row index to the TopRowIndex property and the row will actually become top visible row within the View.