如何在 vb.net 中随机生成一个大整数？

Question

我在生成随机数时遇到问题，例如我想生成一个介于 2 到 579018135005309

之间的随机数

我在 vb.net 中尝试随机函数，但它无法计算 BigInteger

Function RandomNumber(ByVal min As BigInteger, ByVal max As BigInteger) As BigInteger
     Static Generate As System.Random = New System.Random()

     Return Generate.Next(min, max)
 End Function

还有其他方法可以从大值中获取随机数吗？

Answer 1

不是随机性方面的专家，但认为这可能是一个有趣的小函数。

此答案的一部分来自上面评论中的link（C# A random BigInt generator），但扩展到要求它们在一定范围内。

这是我想出的：

Public Function GenerateRandom(min as biginteger, max as biginteger) As BigInteger

    Dim bigint As BigInteger

    Do
        ' find the range of number (so we can generate #s from 0 --> diff)
        Dim range as BigInteger = max - min

        ' create random bigint fitting for the range
        Dim bytes As Byte() = range.ToByteArray()
        Using rng As New RNGCryptoServiceProvider()
            rng.GetBytes(bytes)
        End Using

        ' ensure positive number (remember we're using 0 --> diff)
        bytes(bytes.Length - 1) = bytes(bytes.Length - 1) And CByte(&H7f)

        ' add minimum to this positive number so that the number is now 
        ' a candiate for being between min&max
        bigint = min + New BigInteger(bytes)

        ' since we now only have a random number within a certain number of
        ' bytes it could be out of range. If so, just try again.

    Loop While (bigint > max)

    ' we have a number in the given range!
    return bigint 

End Function

如何在 vb.net 中随机生成一个大整数？

How to Random a biginteger in vb.net?

vb.net

biginteger

visual-studio-2010