The column span: the difference between the right and left boundaries delimiting the group of cells occupied by this view. The default is one. See Android.Widget.GridLayout.Spec.

Must be an integer value, such as "100".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

[Android Documentation]