vb.net OLEDB Parametarize查询

Question

当我将参数放入我的OLEDB代码时，它成功编译，但它没有完成任务。例如，删除数据代码：

    Try
        If dbconn.State = ConnectionState.Closed Then
            dbconn.Open()
        End
        Dim dbCommand As OleDbCommand = New OleDbCommand
        dbCommand.CommandText = "DELETE FROM UsersTB WHERE First_Name =?"
        dbCommand.Connection = dbconn
        dbCommand.Parameters.AddWithValue("@row", 0)
        Dim rows = dgvusers.SelectedRows
        For Each row In rows
            dbCommand.Parameters("@row").Value = row.Cells("First_Name").Value
            dbCommand.Connection = dbconn
            dbCommand.ExecuteNonQuery()
        Next
        MsgBox("Deleted")
    Catch ex As Exception
        ex.ToString()
    End Try

当我编译时，这个代码写在按钮上，然后单击按钮它不会删除我尝试将其放在try catch上的数据，并将msgbox用于指示命令是否成功，并指示其＆＃34 ;删除＆＃34;但它没有用。