vb.net - Visual Basic Teacher 示例无法正常工作

Question

刚刚在类里面进行了演练，我们老师给我们的示例代码没有返回值。我目前的任务遇到了很多麻烦，因为我不明白它有什么问题。它应该采用用户输入的两个数字并将它们加在一起以获得总税率，但它仍然返回全 0 代码如下:

Public Class Form1

Private Sub BtnCalc_Click(ByVal sender As System.Object, _ 
 ByVal e As System.EventArgs) Handles BtnCalc.Click

    Dim amount1 As Decimal
    Dim amount2 As Decimal
    Dim myinvoice As Invoice

    myinvoice = New Invoice

    myinvoice.setlineitemamount(amount1 = Convert.ToDecimal(TextBoxAmt1.Text))
    myinvoice.setlineitemamount2(amount2 = Convert.ToDecimal(TextBoxAmt2.Text))

    LblTotal.Text = myinvoice.calculateinvoicetotal

    MessageBox.Show(myinvoice.getlineitemamount2)

    amount1 = TextBoxAmt1.Text
    amount2 = TextBoxAmt2.Text

End Sub

End Class

这是我的类中的代码:

Public Class Invoice
'created new class for my invoice functions

Private lineItemamount1 As Decimal
Private lineItemamount2 As Decimal
Private lineItemamount3 As Decimal
Private lineItemamount4 As Decimal
Private invoiceDate As Date
Private customer As Integer
Private invoicetotal As Decimal
Private invoicetaxrate As Decimal = 0.1

Public Function getlineitemamount()
    Return lineItemamount1
End Function

Public Sub setlineitemamount(ByVal amount1 As Decimal)
    lineItemamount1 = amount1
End Sub

Public Function getlineitemamount2()
    Return lineItemamount2
End Function

Public Sub setlineitemamount2(ByVal amount2 As Decimal)
    lineItemamount2 = amount2
End Sub

Public Function calculateinvoicetotal()
    Return (lineItemamount1 + lineItemamount2) * invoicetaxrate
End Function

End Class

Answer 1

你能试试这个吗

amount1 = Convert.ToDecimal(TextBoxAmt1.Text)
myinvoice.setlineitemamount(amont1)

和

Public Function getlineitemamount2() as decimal

当它是一个函数时，你需要指定返回值的类型 但我不确定这是你的问题，但值得一试