用于随机数生成器的 Visual Basic 文本框数组

Visual Basic Text Box Array for random number generator

提问人：Connorjones91 提问时间：11/19/2014 最后编辑：Connorjones91 更新时间：11/25/2014 访问量：2029

问：

我想做一个随机数生成器。这是为了学校的家庭作业。我似乎无法让它工作。

任务是制作一个随机数生成器，将 20 个数字生成到 20 个文本框中，以提出 10 个数学问题。

它需要尽可能高效。我需要帮助，因为我只能这样做，但它真的很低效，而且代码很长。

Dim RandomNumberAHigh As Integer = 12 'Here I am declaring my highest number for the random number generator to use. This will be the highest number the maths quiz will ask the students in the questions.
Dim RandomNumberALow As Integer = 1 'Here I am declaring my lowest number for the random number generator to use. This will be the lowest number the maths quiz will ask the students in the questions.
Dim Random As Integer = 0 'Her I am declaring a variable that will be used to insert the numbers from the random number generator in the quiz text boxes.
Randomize()
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd1.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd4.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd7.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd10.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd13.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd16.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd19.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd22.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd25.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd28.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd3.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd6.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd9.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd12.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd15.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd18.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd21.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd24.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd27.Text = (Random)
Random = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
Rnd30.Text = (Random)
vb.net 随机

评论

答：

1赞 Dotnetter 11/19/2014 #1

尝试对所有文本框使用 foreach 循环，如下所示：

Dim RandomNumberAHigh As Integer = 12
Dim RandomNumberALow As Integer = 1
Dim Random As Integer = 0
For Each txt As Control In Me.Controls
    If TypeOf txt Is TextBox Then
        txt.Text = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
    End If
Next

评论

0赞 Brett Caswell 11/25/2014
不先做就不用Rnd()Randomize()
0赞 Cody Popham 11/19/2014 #2

我可能会遍历页面上的所有控件，检查它是否是一个文本框，如果是，则为其分配一个数字。此外，使用函数生成您的号码以清理和加速它。

对于您的速度问题，这可能是因为您每次都要创建一个新的随机实例。请看下面的功能。

  'Create a control object, loop through every control. If its a textbox, generate your number         
  Dim cControl As Control
    For Each cControl InMe.Controls
        If (TypeOf cControl Is textbox) Then
            cControl.Text = GetRandom(RandomNumberALow,RandomNumberAHigh)
        End If
    Next cControl

 Public Function GetRandom(ByVal Min As Integer, ByVal Max As Integer) As Integer
 ' by making Generator static, we preserve the same instance '
 ' (i.e., do not create new instances with the same seed over and over) '
 ' between calls '
     Static Generator As System.Random = New System.Random()
     Return Generator.Next(Min, Max)
 End Function
0赞 Brett Caswell 11/25/2014 #3

就像 @Idle_Mind 的答案一样（在您的重复线程中，可能会被删除），这使用 Textbox 的 Name 属性来确定是否应为 Text 属性分配一个生成的值。

这里的区别在于我通过控件集合进行枚举;在 For Each 循环中使用 IEnumerable。这样，我就不必根据控件集合的长度检查控件集合，也不必在循环的处理过程中强制转换控件。

Sub RandomizeTextBoxes(min As Integer, max As Integer)
    Dim r As Random = New Random()
    Dim RandomTextboxes As IEnumerable(Of TextBox) = Me.Controls.OfType(Of TextBox).Where(AddressOf DoesTextboxNameContainRnd)
    For Each tbControl As TextBox In RandomTextboxes
        tbControl.Text = r.Next(min, max)
    Next
End Sub

Function DoesTextboxNameContainRnd(tbControl As TextBox) As Boolean
    Return tbControl.Name.Contains("Rnd")
End Function

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    RandomizeTextBoxes(1, 50)
End Sub

通过将 addressof 函数传递给集合（通过 where 方法），我传递了一个预测函数，该函数将针对集合中的每个对象进行测试，以及由此产生的在该谓词中返回 true 的对象的新集合。这种编程风格称为逆变编程。DoesTextboxNameContainRnd

评论

0赞 Brett Caswell 11/25/2014
此外，可以使用此样式来修改文本框集合的 textbox.text 值，因此根本不执行 for 循环。

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