VB.NET產生隨機串或隨機數位方法總結

本文一共介紹了5種產生隨機數方式，具體如下：

第一種：轉載的方法

Public Enum stringtype    allstring = 1    '大小寫字母    allnumic = 2    '數字    str_num = 3    '大小寫字母+數字    str_upper = 4    '大寫字母    str_lower = 5 '大寫字母   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

第二種：網上尋找

Public Function GetOAuthNonce() As String ' 得到隨機值    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

第三種：原來是C#轉換

   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

第四種：利用VB6轉換

Function makeRand(ByVal maxLen As Integer) As String '產生簽名時用隨機串    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

第五種：直接用VB.NET函數

Dim rand As Random = New System.Random(10)‘這裡10就代表是10為 Debug.Print(rand.Next().ToString)

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