You can actually set the ReadOnly property for the DataTable column!
Dim dt As DataTable = oDL.GetTheItems()
dt.Columns("Selected").ReadOnly = false
DataGridView1.DataSource = dt
First Set DataTable ReadOnly Property False. Then Set Gridview ReadOnly Property false.
EX-
DataTable dt=("Select * prom priceList");
dt.Columns["Rate"].ReadOnly = false;
DataGrid View dgv=.dataSource=dt;
dgv.Columns["Rate"].ReadOnly = false;