Question

我需要为学校创建一个程序。要求是：设计一个有五个按钮的程序，每个等级一个。每次按下按钮，它都会将该等级增加1。同时，它会更新一个标签，显示通过考试的当前学生百分比（成绩高于F）。我们一直在使用计数器和if ... else语句/ case ... select语句。

这是我到目前为止所做的：

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Static intCounterA As Integer = 0
    Static intCounterB As Integer = 0
    Static intCounterC As Integer = 0
    Static intCounterD As Integer = 0
    Static intCounterF As Integer = 0
    Static intCounterTotal As Integer = 0

    Dim dblTotal As Double


    dblTotal = intCounterTotal

    Me.lblTotal.Text = dblTotal


End Sub

Private Sub btnA_Click(sender As Object, e As EventArgs) Handles btnA.Click
    Static intCounterA As Integer = 0
    intCounterA = intCounterA + 1
    Me.lblA.Text = intCounterA
End Sub

Private Sub btnB_Click(sender As Object, e As EventArgs) Handles btnB.Click
    Static intCounterB As Integer = 0
    intCounterB = intCounterB + 1
    Me.lblB.Text = intCounterB
End Sub

Private Sub btnC_Click(sender As Object, e As EventArgs) Handles btnC.Click
    Static intCounterC As Integer = 0
    intCounterC = intCounterC + 1
    Me.lblC.Text = intCounterC
End Sub

Private Sub btnD_Click(sender As Object, e As EventArgs) Handles btnD.Click
    Static intCounterD As Integer = 0
    intCounterD = intCounterD + 1
    Me.lblD.Text = intCounterD
End Sub

Private Sub btnF_Click(sender As Object, e As EventArgs) Handles btnF.Click
    Static intCounterF As Integer = 0
    intCounterF = intCounterF + 1
    Me.lblF.Text = intCounterF
End Sub

我只需要lblTotal来显示正在通过的学生的百分比，而我所拥有的只是返回NaN。有什么帮助吗？

Answer 1

正如我在评论中所说，试试这样的事情。

我建议缩短变量名，因为它会使代码编写起来很乏味。

每当你开始需要多个变量互相交流时，使用集合或数组写起来会更容易，但我知道你还在学习。

在UpdateTotals子句中，我添加了两个不是真正需要的变量，只是为了让代码更容易阅读。

出于某种原因，您在Form1_Load范围内将变量声明为静态，这似乎是错误的。

如果你想以这种方式使用它们，请将它们设为全局。

此外，请勿在按钮点击事件中重新定义它们...

修改：代码已构建并正常运行：

Public Class Form1
    Dim intCounterA As Integer = 0
    Dim intCounterB As Integer = 0
    Dim intCounterC As Integer = 0
    Dim intCounterD As Integer = 0
    Dim intCounterF As Integer = 0
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.lblA.Text = intCounterA
        Me.lblB.Text = intCounterB
        Me.lblC.Text = intCounterC
        Me.lblD.Text = intCounterD
        Me.lblF.Text = intCounterF
    End Sub
    Private Sub UpdateTotal()
        Dim n, d
        n = (intCounterA + intCounterB + intCounterC + intCounterD + intCounterF) - intCounterF
        d = intCounterA + intCounterB + intCounterC + intCounterD + intCounterF
        Me.lblTotal.Text = Math.Round(((n / d) * 100), 2) & "%" 'Display as percentage - round to 2 decimals
    End Sub
    Private Sub btnA_Click(sender As Object, e As EventArgs) Handles btnA.Click
        intCounterA = intCounterA + 1
        Me.lblA.Text = intCounterA
        UpdateTotal()
    End Sub
    Private Sub btnB_Click(sender As Object, e As EventArgs) Handles btnB.Click
        intCounterB = intCounterB + 1
        Me.lblB.Text = intCounterB
        UpdateTotal()
    End Sub
    Private Sub btnC_Click(sender As Object, e As EventArgs) Handles btnC.Click
        intCounterC = intCounterC + 1
        Me.lblC.Text = intCounterC
        UpdateTotal()
    End Sub
    Private Sub btnD_Click(sender As Object, e As EventArgs) Handles btnD.Click
        intCounterD = intCounterD + 1
        Me.lblD.Text = intCounterD
        UpdateTotal()
    End Sub
    Private Sub btnF_Click(sender As Object, e As EventArgs) Handles btnF.Click
        intCounterF = intCounterF + 1
        Me.lblF.Text = intCounterF
        UpdateTotal()
    End Sub
End Class

创建一个程序来更新标签，该标签显示通过考试的当前学生百分比

1 个答案: