Adds the specified System.Windows.Forms.ListViewGroup to the collection.
- group
- The System.Windows.Forms.ListViewGroup to add to the collection.
The index of the group within the collection, or -1 if the group is already present in the collection.
Use this method to add an existing System.Windows.Forms.ListViewGroup to the collection. You cannot add a System.Windows.Forms.ListViewGroup to the collection more than once. When you call the ListViewGroupCollection.Add(ListViewGroup) method using a System.Windows.Forms.ListViewGroup that is already in the collection, the addition fails and -1 is returned.
To add multiple groups to the collection, use the ListViewGroupCollection.AddRange(ListViewGroup[]) method.