如何將一個子過程的值傳遞給函數過程....我是否將整個子過程傳遞給函數過程參數？

Question

我是一名學生做一個任務，我如何將一個子過程的值傳遞給一個函數過程....我想將值從decSubtotal傳遞給一個名爲CalculateDiscount的函數過程;看看我的代碼 -

Private Sub CalculateSubtotal(ByVal _decTENTCOST As Decimal, ByVal _decRVCOST As Decimal, _ 
           ByVal _decCABINCOST As Decimal) 

    Dim decSubtotal As Decimal 
    Dim intSiteType, intNumberOfNights As Integer 

    intSiteType = cboSiteType.SelectedIndex() 
    intNumberOfNights = Convert.ToInt32(txtNumberOfNights.Text) 

    Select Case intSiteType 
     Case 0 
      decSubtotal = _decTENTCOST * intNumberOfNights 
     Case 1 
      decSubtotal = _decRVCOST * intNumberOfNights 
     Case 2 
      decSubtotal = _decCABINCOST * intNumberOfNights 

    End Select 

    lblSubtotal.Text = decSubtotal.ToString() 

End Sub 

Answer 1

你會打電話給這樣的功能，（你完Select語句之後，可能）

Dim MyValue = CalculateDiscount(decSubTotal) 

你CalculateDiscount可能是這樣的：

Function CalculateDiscount(byval pSubTotal as Decimal) as Decimal 

    .... 

    return MyDiscountedAmount 

End Function 

在VB.NET中，我們只說「subs」和「functions」。兩者都是子程序，也稱爲子程序（對某些程序）。函數總是返回一個值，而subs不會返回一個值。