How to add Items in the DatagridViewComboboxColumn of DatagridView during runtime

[Ehtesham Siddiqui]

Just read this i think this will give clearer idea.
Please check.
I have a datagridview with three columns which is filled using Datareader. There is a DatagridViewComboboxcolumn in the datagridView.

I want this DatagridViewComboboxcolumn should also be filled using datareader.

Please suggest how can i add items to DatagridViewComboboxcolumn using Datareader. Below is the code that i have tried.

Here dr is SqlDatareader
I want to assign the value of Column3 to my DatagridViewComboboxcolumn

Datagridview.Rows.Add(dr("Column1").ToString, dr("Column2"),dr("Column3 "))

Please suggest me how can i add items to DatagridViewComboboxcolumn,that my only priority rest requirement i will do it myself.
thanks.