Vb. NET generating random string or random number method summary

This article introduces a total of 5 ways to generate random numbers, as follows:
The first method: reprint

Public Enum stringtype
    allstring = 1 'Capital letters
    allnumic = 2 'number
    str_num = 3 'Capital letters + numbers
    str_upper = 4 'Capital letters
    str_lower = 5 'Capital letters
  End Enum
  Function GenerateRandom (ByVal Length As Integer, ByVal s As stringtype) As String
    Dim strtemp As String = ""
    Dim constant () As String = Nothing
    Select Case s
      Case stringtype.allnumic
        strtemp = "0,1,2,3,4,5,6,7,8,9"
        constant = strtemp.Split (",")
      Case stringtype.allstring
        strtemp = "a, b, c, d, e, f, g, h, i, j, k, m, n, o, p, q, r, s, t, u, v, w, x, y , z, A, B, C, D, E, F, D, G, H, I, J, K, L, M, N, P, Q, R, S, T, U, V, W, X , X, Y, Z "
        constant = strtemp.Split (",")
      Case stringtype.str_lower
        strtemp = "a, b, c, d, e, f, g, h, i, j, k, m, n, o, p, q, r, s, t, u, v, w, x, y ,z"
        constant = strtemp.Split (",")
      Case stringtype.str_num
        strtemp = "a, b, c, d, e, f, g, h, i, j, k, m, n, o, p, q, r, s, t, u, v, w, x, y , z, A, B, C, D, E, F, D, G, H, I, J, K, L, M, N, P, Q, R, S, T, U, V, W, X , X, Y, Z, 0,1,2,3,4,5,6,7,8,9 "
        constant = strtemp.Split (",")
      Case stringtype.str_upper
        strtemp = "A, B, C, E, F, D, G, H, I, J, K, L, M, N, P, Q, R, S, T, U, V, W, X, Y ,Z"
        constant = strtemp.Split (",")
    End Select
    Dim NewRandom As System.Text.StringBuilder = New System.Text.StringBuilder (Length)
    Dim rd As Random = New Random ()
    Dim i As Integer
    For i = 0 To Length-1 Step i + 1
      NewRandom.Append (constant (rd.Next (constant.Length-1)))
    Next
    Return NewRandom.ToString ()
  End Function
The second kind: online search

Public Function GetOAuthNonce () As String 'Get random value
    Dim result As String = System.Guid.NewGuid (). ToString ()
    result = result.Replace ("-", "")
    Return result.Substring (0, 10)
  End Function
Public Function RandCode (ByVal n As Integer) As String
    Dim arrChar As Char () = New Char () {"a" c, "b" c, "d" c, "c" c, "e" c, "f" c, _
                      "g" c, "h" c, "i" c, "j" c, "k" c, "l" c, _
                      "m" c, "n" c, "p" c, "r" c, "q" c, "s" c, _
                      "t" c, "u" c, "v" c, "w" c, "z" c, "y" c, _
                      "x" c, "0" c, "1" c, "2" c, "3" c, "4" c, _
                      "5" c, "6" c, "7" c, "8" c, "9" c, "A" c, _
                      "B" c, "C" c, "D" c, "E" c, "F" c, "G" c, _
                      "H" c, "I" c, "J" c, "K" c, "L" c, "M" c, _
                      "N" c, "Q" c, "P" c, "R" c, "T" c, "S" c, _
                      "V" c, "U" c, "W" c, "X" c, "Y" c, "Z" c}
    Dim num As New StringBuilder ()
    Dim rnd As New Random (DateTime.Now.Millisecond)
    For i As Integer = 0 To n-1
      num.Append (arrChar (rnd. [Next] (0, arrChar.Length)). ToString ())
    Next
    Return num.ToString ()
  End Function
The third kind: it turns out to be C # conversion

   
Public Function RandCode (ByVal n As Integer) As String
    Dim arrChar As Char () = New Char () {"a" c, "b" c, "d" c, "c" c, "e" c, "f" c, _
                      "g" c, "h" c, "i" c, "j" c, "k" c, "l" c, _
                      "m" c, "n" c, "p" c, "r" c, "q" c, "s" c, _
                      "t" c, "u" c, "v" c, "w" c, "z" c, "y" c, _
                      "x" c, "0" c, "1" c, "2" c, "3" c, "4" c, _
                      "5" c, "6" c, "7" c, "8" c, "9" c, "A" c, _
                      "B" c, "C" c, "D" c, "E" c, "F" c, "G" c, _
                      "H" c, "I" c, "J" c, "K" c, "L" c, "M" c, _
                      "N" c, "Q" c, "P" c, "R" c, "T" c, "S" c, _
                      "V" c, "U" c, "W" c, "X" c, "Y" c, "Z" c}
    Dim num As New StringBuilder ()
    Dim rnd As New Random (DateTime.Now.Millisecond)
    For i As Integer = 0 To n-1
      num.Append (arrChar (rnd. [Next] (0, arrChar.Length)). ToString ())
    Next
    Return num.ToString ()
  End Function
The fourth: use VB6 conversion

Function makeRand (ByVal maxLen As Integer) As String 'Use random string when generating signature
    Dim strNewPass As String = vbNullString
    Dim lower As Long
    Dim whatsNext As Long
    Dim upper As Long
    Dim intCounter As Long
    Randomize ()
    For intCounter = 1 To maxLen
      whatsNext = Int ((1-0 + 1) * Rnd () + 0)
      If whatsNext = 0 Then
        upper = 122
        lower = 100
      Else
        upper = 57
        lower = 48
      End If
      strNewPass = strNewPass & Chr (Int ((upper-lower + 1) * Rnd () + lower))
    Next
    makeRand = strNewPass
  End Function
Fifth: use VB.NET function directly

Dim rand As Random = New System. Random (10) ‘here 10 means 10 is
 Debug.Print (rand.Next (). ToString)