for (int i = 0; i < Gridview1.Rows.Count; i++)
{
DropDownList ddlx = gvdata.Rows[i].FindControl("ddlID") as DropDownList
string XX = ddlxBrand.SelectedItem.Value;
}
for (int i = 0; i < GridView1.Rows.Count; i++)
{
DropDownList ddl= GridView1.Rows[i].FindControl("DropDownList1") as DropDownList;
string a = ddl.SelectedValue;
}