NULL - Interger input - VB.X (2010)

[masokis]

Integer variables can only contain Integer values. You don't use DBNull at all except when transferring NULL values to or from a database using ADO.NET.

You don't need a hack. If you were to explain what you're actually trying to achieve then we could explain the proper way to achieve it.

Thanks for reply, jmcilhinney
Ok, i'm try to achieve a proper input box. which only allow integer . backspace, null (empty), char or string is not allowed... but i could not configure it.. i create a function to call by a button. i has been mod my code.. now it look like below :

Private Sub GetDataToDGV()
        Dim row As Integer = DataGridView1.Rows.Count      
        Dim n1 As String
        Dim N As Integer       
        Do
            n1 = InputBox("Enter the number of order :")
            If n1 <> "" Then
                MessageBox.Show(n1)
                N = Convert.ToInt32(n1)
            Else
                MessageBox.Show("Wrong input! Please try again!")
            End If           
        Loop Until n1 <> String.Empty       
        Dim jumlah As Decimal
        jumlah = Decimal.Round(N * txt_harga.Text).ToString("f2")
        Me.DataGridView1.Rows.Add(row, kodMakanMinum, txt_foodDrinkName.Text, N, jumlah)
    End Sub

so.. i has settle the null input!
but... i still has problem , when end-user input backspace, null (empty), char or string.

here.. a screenshot :


hurmm..