Vb.net 随机数生成器重复相同的数字

Question

我应该在随机数生成器编码中添加什么，这样数字就不会连续重复更多次？

我的随机数生成器看起来像这样：

Dim rn As New Random
TextBox1.Text = rn.Next(1, 4)
If TextBox1.Text = 1 Then
    Form4.Show()
    Form4.Timer1.Start()
End If
If TextBox1.Text = 2 Then
    Form7.Show()
    Form7.Timer1.Start()
End If
If TextBox1.Text = 3 Then
   Form8.Show()
   Form8.Timer1.Start()
End If

Answer 1

给定 N（目前 N = 3，但正如你所说，它可能是别的东西），尝试构造 1、...、N 的随机排列，然后按生成的顺序打开文本框。请注意，这意味着您一次生成 N 个数字并将它们全部用完，然后生成更多 N 个数字。搜索"随机排列"以找到算法。

Answer 2

将您的随机实例"rn"移出到类（表单）级别，以便它只为表单创建一次，并且同一实例被一遍又一遍地使用：

Public Class Form1
    Private rn As New Random
    Private Sub SomeMethod()
        TextBox1.Text = rn.Next(1, 4)
        If TextBox1.Text = 1 Then
            Form4.Show()
            Form4.Timer1.Start()
        End If
        If TextBox1.Text = 2 Then
            Form7.Show()
            Form7.Timer1.Start()
        End If
        If TextBox1.Text = 3 Then
            Form8.Show()
            Form8.Timer1.Start()
        End If
    End Sub
End Class

Answer 3

要获取介于 1 和 N（含）之间的随机整数值，您可以使用以下内容。

CInt(Math.Ceiling(Rnd() * n))

Answer 4

如果你希望每个数字只使用一次，你需要做这样的事情：

Const FirstNumber As Integer = 1
Const LastNumber As Integer = 5
' Fill the list with numbers
Dim numberList as New List(Of Integer)
For i As Integer = FirstNumber To LastNumber Step 1
    numberList.Add(i)
Next i
Dim rand as New Random()
While numberList.Count > 0
    ' draw a random number from the list
    Dim randomIndex As Integer = rand.Next(0, numberList.Count - 1)
    Dim randomNumber As Integer = numberList(randomIndex)
    ' Do stuff with the number here        
    TextBox1.Text = randomNumber
    ' remove the number from the list so it can't be used again
    numberList.RemoveAt(randomIndex)
End While