private void deleteBtn_Click(object sender, EventArgs e) { int itemIndex = 0; DataTable myTable = (DataTable)dataGrid1.DataSource; List <string> argumentsList = new List <string>(); foreach (DataRow item in myTable.Rows) { if (dataGrid1.IsSelected(itemIndex)) { if (check.ToString() == "Movies") { argumentsList.Add(item["Tytuł"].ToString()); } if (check.ToString() == "Comments") { argumentsList.Add(item["Email"].ToString()); } if (check.ToString() == "Users") { argumentsList.Add(item["Email"].ToString()); } } itemIndex++; } MongoQueries.DeleteMany(argumentsList, check.ToString()); getAllMoviesBtn_Click(sender, e); }