transfering rows between datatables

as per your requirements you need a one data table for hold the second datagridview rows values. when you pass one row to another second gridviews, should be add in datatable and then bind the gridview of this table.

Get GridViewDatatable

Bind Again second Gridview.

Your code looks good except, you should place datagridview2.datasource outside the foreach loop.

Also, what do you mean by adding another row?

By code or by UI? it would help us to understand if you can explain the adding row.