vb.net - 如何检查测验答案是否正确？

Question

我正在为我的计算机科学课做一个测验，基本概念是你有 15 个关键字和 15 个定义。都需要随机显示，并且必须出现正确答案。用户必须将正确的定义与关键字匹配两次，然后不会再次显示该关键字和定义。当所有人都回答了两次后，测验就结束了。

我已将关键字和定义存储在同一个文件中，以免它们不同步。文本文件如下所示:

Keyword1,Definition1
Keyword2,Definition2
Keyword3,Definition3
...

感谢 StackOverflow 上其他人的帮助，我设法完成了随机化和字典。作为引用，看起来像这样:

Public Class form1

Const NUMBER_OF_ANSWERS As Integer = 3

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    Dim kv As New Dictionary(Of String, String)
    For Each line As String In IO.File.ReadAllLines("C:\Users\Matt\Documents\keywords.txt")
        Dim parts() As String = line.Split(",")
        kv.Add(parts(0), parts(1))
    Next

    Dim r As New Random
    Dim kvRandom As List(Of KeyValuePair(Of String, String)) =
      kv.OrderBy(Function() r.Next).ToList

    'questions will appear in random order
    For Each line As KeyValuePair(Of String, String) In kvRandom
        Dim keyword As String = line.Key
        Dim correctDefinition As String = line.Value

        Dim keywords As New List(Of String)
        keywords.Add(keyword)
        keywords.AddRange(kv.Keys.Except({keyword}).
          OrderBy(Function() r.Next).Take(NUMBER_OF_ANSWERS - 1))

        Dim definitionsRandom As List(Of String) =
          keywords.Select(Function(x) kv(x)).OrderBy(Function() r.Next).ToList

        LabelKeyword.Text = keyword
        RadioButtonDef1.Text = definitionsRandom(0)
        RadioButtonDef2.Text = definitionsRandom(1)
        RadioButtonDef3.Text = definitionsRandom(2)
    Next

End Sub

此代码完美运行。我现在需要做的，但我发现在 button1_click 上我需要检查答案是否成功。换句话说，检查所检查的定义是否是关键字的正确答案。如果是，则显示正确答案消息，否则显示错误消息并再次随机化。

另一个要求是每个关键字应该与其定义匹配两次，完成后将从列表中删除并且不再显示。换句话说，每个问题必须完成两次，完成后该问题将不会再次显示。当所有问题都回答两次后，测验结束。我不知道该怎么做，所以非常感谢您的帮助。

抱歉，如果很难理解我在问什么，我会尽量说清楚。

Answer 1

部分问题是字典结构只包含两部分；在这种情况下，问题和答案。然而，还需要第三部分:回答的次数。这可以通过创建一个 Answer 类来实现，该类包含答案字符串和一个 Answered bool 值，例如:

Public Class Answer
    Public Answer as String
    Public Answered as Boolean
End Class

...然后:

....
Private kv As Dictionary(Of String, Answer)
Private keyword As String 
Private correctDefinition As String 

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    kv = New Dictionary(Of String, Answer)
    For Each line As String In IO.File.ReadAllLines("C:\Users\Matt\Documents\keywords.txt")
        Dim parts() As String = line.Split(",")
        kv.Add(parts(0), New Answer with {.Answer = parts(1), .Answered = False}})
    Next
    RandomiseAnswers()
End Sub

kv、keyword 和 correctDefinition 必须是表单的全局变量，以允许与 button1_click 调用的代码进行交互

第一次回答问题时，将.Answered设置为True，第二次从列表中删除，在button1_click:

If (RadioButton1.Checked and RadioButton1.Text = correctDefinition) or (RadioButton2.Checked and RadioButton2.Text = correctDefinition) or (RadioButton3.Checked and RadioButton3.Text = correctDefinition) then
    If kv(keyword).Answered Then
        kv.Remove(keyword)
    Else
        kv(keyword).Answered = True
    End If
End If
RandomiseAnswers()

要防止 Form1_load 和 button1_click 中的重复代码，请创建一个子例程:

Private Sub RandomiseAnswers()
    Dim r As New Random
    Dim kvRandom As List(Of KeyValuePair(Of String, Answer)) =
      kv.OrderBy(Function() r.Next).ToList

    'questions will appear in random order
    For Each line As KeyValuePair(Of String, Answer) In kvRandom
        Dim keyword As String = line.Key
        Dim correctDefinition As String = line.Value.Answer

        Dim keywords As New List(Of String)
        keywords.Add(keyword)
        keywords.AddRange(kv.Keys.Except({keyword}).
          OrderBy(Function() r.Next).Take(NUMBER_OF_ANSWERS - 1))

        Dim definitionsRandom As List(Of String) =
          keywords.Select(Function(x) kv(x)).OrderBy(Function() r.Next).ToList

        LabelKeyword.Text = keyword
        RadioButtonDef1.Text = definitionsRandom(0)
        RadioButtonDef2.Text = definitionsRandom(1)
        RadioButtonDef3.Text = definitionsRandom(2)
    Next
End Sub