Question

我正在尝试在Visual Basic中编写一个简单的程序，它通过一个类传递一个变量，计算它，然后返回它。我的表单“Pizza”有两组，每组有3个单选按钮。单击“总计”按钮后，比萨饼大小的价格将添加到比萨饼外壳价格中。我通过故障排除发现它只添加了“createPizza.Crust”+“createPizza.Size”。我错过了什么谢谢你的帮助。

Form "Pizza"
Public Class Pizza

Private Sub btnTotal_Click(sender As Object, e As EventArgs) Handles btnTotal.Click
    If rThin.Checked = True Then
        createPizza.Crust = 1
    ElseIf rPan.Checked = True Then
        createPizza.Crust = 2
    ElseIf rStuff.Checked = True Then
        createPizza.Crust = 3
    End If

    If rSm.Checked = True Then
        createPizza.Size = 1
    ElseIf rMm.Checked = True Then
        createPizza.Size = 2
    ElseIf rLg.Checked = True Then
        createPizza.Size = 3
    End If

    lblTotal.Text = "Total: " + createPizza.PizTotal.ToString()

  End Sub
End Class

班级“createPizza”

Public Class createPizza

Public Shared Size As Double
Public Shared Crust As Double

Public Shared Property pizzaCrust As Double
    Get
        Return Crust
    End Get
    Set(ByVal crustpr As Double)
        If Crust = 1 Then
            crustpr = 1
        ElseIf Crust = 2 Then
            crustpr = 1.5
        ElseIf Crust = 3 Then
            crustpr = 3
        End If
        Crust = crustpr
    End Set
End Property

Public Shared Property pizzaSize As Double
    Get
        Return Size
    End Get
    Set(ByVal sizepr As Double)
        If Size = 1 Then
            sizepr = 10.0
        ElseIf Size = 2 Then
            sizepr = 12.5
        ElseIf Size = 3 Then
            sizepr = 15
        End If
        Size = sizepr
    End Set
End Property

Public Shared Function PizTotal() As Decimal
    Return pizzaCrust + pizzaSize
End Function

End Class

Answer 1

我已经更新了适合VBA的课程。

Class createPizza

Private Size As Double
Private Crust As Double


Public Function PizTotal() As Double
    PizTotal = pizzaCrust + pizzaSize
End Function


Public Property Get pizzaCrust() As Double
    pizzaCrust = Crust
End Property

Public Property Let pizzaCrust(ByVal vNewValue As Double)
    Select Case vNewValue
    Case 1
        crustpr = 1
    Case 2
        crustpr = 1.5
    Case 3
        crustpr = 3
    End Select

    Crust = crustpr
End Property

Public Property Get pizzaSize() As Double
    pizzaSize = Size
End Property

Public Property Let pizzaSize(ByVal vNewValue As Double)
    Select Case vNewValue
    Case 1
        sizepr = 10#
    Case 2
        sizepr = 12.5
    Case 3
        sizepr = 15
    End Select

    Size = sizepr
End Property

<强>模块示例代码

Sub sample()
    Dim a As New createPizza
    a.pizzaCrust = 2
    a.pizzaSize = 3

    MsgBox a.PizTotal
End Sub

Answer 2

您的PizTotal功能仅返回Size + Crust，因为您的pizzaSize和pizzaCrust属性分别返回Size和Crust的值。我可以看到您必须在属性设置中计算费用的代码，但是您从不致电pizzaSize和pizzaCrust的设置者，因此永远不会计算费用。

您的pizzaSize和pizzaCrust属性并没有多大意义。例如，地壳属性设置将价格作为输入，但如果Crust为1,2或3，则重置价格，然后将价格存储在Crust变量中。如果你写了以下逻辑：

Dim p as New createPizza
p.Crust = 2
p.pizzaCrust = 12345678
Dim price1 As Double = p.pizzaCrust
p.pizzaCrust = 12345678
Dim price2 As Double = p.pizzaCrust

price1为1.5，price2为12345678，因为pizzaCrust都使用Crust的值并修改Crust。您正在使用Crust变量来获取地壳类型和地壳价格，而不区分它们。您应该将外壳类型存储在一个变量中，并将cust成本存储在另一个变量中（或者更好的是只编写一个函数，该函数根据1,2或3的外壳类型返回第一个成本。）

变量不通过类

2 个答案: