Flexible AutoNumber In VB.NET (English)

Flexible Auto number

By using this function you able to make the flexible auto number, why called flexible? Because my function not only generate from number only, but will generate the auto number contained the letter and number. Such as invoice number, purchase order number, etc.

See illustrate on the table below:

Recent Number	Next Number
1	2	3	And so on
00001	00002	00003	And so on
PO-0001	PO-0002	PO-0004	And so on
INV-20.09.2012-00001	INV-20.09.12-00002	INV-20.09.2012-00003	And so on

Let's look at an example of using this function is simply to be easily understood.

1.	Create new project on your VB Express/.NET. Give Name Of Your Project with FlexibleAutoNumber.
2.	Put two labels, two textbox and one button (can be arranged on the picture below).
3.	Add a class in your project and name it with the name clsFunction.vb, see picture below.
4.	Open clsFunction.vb by double-click, then remove the two lines of code there, and paste the following code:
	Public Class clsFunction     Function GetNextNumber(ByVal strBefore As String) As String         Dim temp1 As String = vbNullString         Dim lnStrBefore, lnTemp1 As Integer         temp1 = Val(strBefore) + 1        lnStrBefore = Len(strBefore)         lnTemp1 = Len(temp1)         If lnStrBefore > lnTemp1 Then             Dim a As Integer             For a = lnTemp1 To (lnStrBefore - 1)                 temp1 = "0" & temp1             Next         End If         Return temp1     End Function     Function GetNextString(ByVal strBefore As String) As String         Dim strAwal As String = vbNullString         Dim temp1 As String = vbNullString         Dim lnStrBefore As Integer         lnStrBefore = Len(strBefore)         Dim a, b As Integer         Dim cKarakter As String         b = lnStrBefore + 1         For a = 1 To lnStrBefore             b = b - 1             cKarakter = Mid(strBefore, b, 1)             If IsNumeric(cKarakter) = False Then                 strAwal = Left(strBefore, b)                 temp1 = Right(strBefore, a - 1)                 temp1 = strAwal & GetNextNumber(temp1)'CALLFUNCTION GetNextNumber                 Exit For             End If         Next         Return temp1     End Function     Function FlexibleAutoNumber(ByVal strRecentNumber As String) As String         If IsNumeric(strRecentNumber) Then             Return GetNextNumber(strRecentNumber)         Else             Return GetNextString(strRecentNumber)         End If     End Function End Class
5.	A brief description of 3 functions above. a.    Function GetNextNumber used when the layout consists of digits Numeric only b.    Function GetNextString used when the layout consists of the incorporation of letters and numeric. c.    FlexibleAutoNumber function, this function will call one of  two functions above according to the type number.
6.	Immediately open the Form1 design, and double click on button1, then fill in the coding below:
	Public Class Form1     Dim c As New clsFunction     Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click         Dim a As String = TextBox1.Text         TextBox1.Text = c.FlexibleAutoNumber(a)     End Sub End Class
7.	Save your project and try to run it, please input sample number, eg INV-0001 after the Save button is clicked then the INV-0001 will turn into INV-0002, and so on.  After button Save is clicked
8.	Please explore themselves to use this function in accordance with the program you have created. Good luck and hopefully useful. Just clik Here if want to downlod the Project