MS Access Visual Basic - generate random string in

问题:

We have that old software (made by one of the first employees many years ago) in company that uses Microsoft Access to run. Boss asked me to add a random string generation in the specific text box on click but i have no idea how to do that. I dont have any Microsoft Access programming experience, thats why i am askin you to help.

I managed to create button and text field so far. Thats where it stops. I also managed to access the code for the button action:

Private Sub command133_Click()

End Sub

回答1:

This is one way, will work in Access VBA (which is an older basic than vb.net). It will generate a string with letters and numbers.

Sub test()

    Dim s As String * 8 'fixed length string with 8 characters
    Dim n As Integer
    Dim ch As Integer 'the character
    For n = 1 To Len(s) 'don't hardcode the length twice
        Do
            ch = Rnd() * 127 'This could be more efficient.
            '48 is '0', 57 is '9', 65 is 'A', 90 is 'Z', 97 is 'a', 122 is 'z'.
        Loop While ch < 48 Or ch > 57 And ch < 65 Or ch > 90 And ch < 97 Or ch > 122
        Mid(s, n, 1) = Chr(ch) 'bit more efficient than concatenation
    Next

    Debug.Print s

End Sub

回答2:

Try this function:

Public Function GetRandomString(ByVal iLength As Integer) As String
    Dim sResult As String = ""
    Dim rdm As New Random()

    For i As Integer = 1 To iLength
        sResult &= ChrW(rdm.Next(32, 126))
    Next

    Return sResult
End Function

回答3:

Workin on @Bathsheba code, I did this. It will generate a random string with the number of characters you'd like.

Code :

Public Function GenerateUniqueSequence(numberOfCharacters As Integer) As String

    Dim random As String  ' * 8 'fixed length string with 8 characters
    Dim j As Integer
    Dim ch As Integer   ' each character

    random = ""

    For j = 1 To numberOfCharacters
        random = random & GenerateRandomAlphaNumericCharacter
    Next

    GenerateUniqueSequence = random

End Function

Public Function GenerateRandomAlphaNumericCharacter() As String

    'Numbers : 48 is '0', 57  is '9'
    'LETTERS : 65 is 'A', 90  is 'Z'
    'letters : 97 is 'a', 122 is 'z'

    GenerateRandomAlphaNumericCharacter = ""

    Dim i As Integer

    Randomize
    i = (Rnd() * 2) + 1 'One chance out of 3 to choose one of 3 catégories

    Randomize
    Select Case i
        Case 1 'Numbers
            GenerateRandomAlphaNumericCharacter = Chr(Rnd() * 9 + 48)
        Case 2 'LETTERS
            GenerateRandomAlphaNumericCharacter = Chr(Rnd() * 25 + 65)
        Case 3 'letters
            GenerateRandomAlphaNumericCharacter = Chr(Rnd() * 25 + 97)
    End Select

End Function

I use it with random number of characters, like this :

'Generates random Session ID between 15 and 30 alphanumeric characters
SessionID = GenerateUniqueSequence(Rnd * 15 + 15)

Result :

s8a8qWOmoDvC4jKRjPr5hOY12u 26
TB24qZ4cNfr6EdyY0J 18
6LZRQ9P5WHLNd71LIdqJ 20
KPN0RmlhhJKnVzPTkW 18
R2pNOKWJMKl9KpSoIV2egUNTEb1QC2 30
X8jHuupP6SvEI8Dt2wJi 20