Question

好的所以这个代码是组合框中的项目列表，你必须选择一个项目，然后选择一个喜欢或不喜欢的单选按钮然后点击投票。结果列表框应该每次点击时总计所有投票或者不喜欢投票。当我点击喜欢并按下投票时，结果框中没有显示任何内容，但是当我点击不喜欢并按下投票时，它会显示出来并且总数是正确的，因为我按下并点击了投票，因此每个显示1。它在程序运行的整个过程中一直保持这种状态，所以如果我再打3次就不会在列表框中更新，直到我不喜欢并按下投票。我如何编码以显示和更新喜欢和不喜欢投票？

这是我的代码：

Public Class FoodSurveyForm

   Dim votes As Integer(,) = New Integer(0 To 3, 0 To 1) {}

   ' handles Food Survey Form's Load event
   Private Sub FoodSurveyForm_Load(sender As System.Object,
      e As System.EventArgs) Handles MyBase.Load

      foodsComboBox.SelectedIndex = 0 ' select first food in list
   End Sub ' FoodSurveyForm_Load

   Private Sub voteButton_Click(sender As System.Object, e As System.EventArgs) Handles voteButton.Click

      Dim index As Integer = foodsComboBox.SelectedIndex

      'if statement to add like and dislike votes
      If likeRadioButton.Checked Then
         votes(index, 0) += 1
      ElseIf dislikeRadioButton.Checked Then
         votes(index, 1) += 1
         DisplayVotes()
      End If
   End Sub

   Sub DisplayVotes() 'call DisplayVotes sub procedure

      resultsListBox.Items.Clear()

      'header for resultListBox
      resultsListBox.Items.Add("Menu Item" & ControlChars.Tab & "Like" _
       & ControlChars.Tab & "Dislike")

      For count As Integer = 0 To foodsComboBox.Items.Count - 1
         resultsListBox.Items.Add(foodsComboBox.Items(count).ToString & ControlChars.Tab & votes(count, 0) & _
              ControlChars.Tab & votes(count, 1))
      Next count

   End Sub ' Display Votes
End Class ' FoodSurveyForm

Answer 1

DisplayVotes（）必须超出if块：

    Private Sub voteButton_Click(sender As System.Object, e As System.EventArgs) Handles voteButton.Click

      Dim index As Integer = foodsComboBox.SelectedIndex

      'if statement to add like and dislike votes
      If likeRadioButton.Checked Then
         votes(index, 0) += 1
      ElseIf dislikeRadioButton.Checked Then
         votes(index, 1) += 1
      End If

      DisplayVotes()
   End Sub

食物调查申请书

1 个答案: