For-Next-Statement中的新随机数重复相同的值

Question

我在for-next-statement中创建3个随机字节。

但是，它们对于每个for-next都是相同的，例如“333”或“777”。

我想知道为什么这样，我做错了什么。

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click 

    Dim s As String = String.Empty 

    For i As Integer = 0 To 2 
     s += GetRandomByte().ToString 
    Next 

    Me.TextBox1.Text = s 

End Sub 

Public Function GetRandomByte(Optional ByVal uLow As Byte = 1, Optional ByVal uHigh As Byte = 9) As Byte 

    Dim r As New Random 
    Dim b As Integer = r.Next(CInt(uLow), CInt(uHigh + 1)) 

    Return b 

End Function 

Answer 1

在你的构造新的随机，给它一个新的种子每一次。我喜欢使用当前时间戳的哈希码值

New Random(Now.GetHashCode) 

Answer 2

保持相同的情况下对所有呼叫：

Dim r As New Random() 

Public Function GetRandomByte(Optional ByVal uLow As Byte = 1, Optional ByVal uHigh As Byte = 9) As Byte 
    Return r.Next(CInt(uLow), CInt(uHigh + 1)) 
End Function 

，或者传递给随机构造种子：

Dim r As New Random(CInt(Date.Now.Ticks And &h0000FFFF))