Question

不知道为什么会发生这种情况，但利率应该是17.9％，但是工作为19.something％。我已经尝试了很多方法来解决它但无法让它完全正常工作。举个例子，到目前为止，我总共有200欧元。 17.9％的利息应为€35.80。但即将到来的是€38.89任何想法？

Public Class frmFinancePackage

'Interest rate = 17.9%
Const interestRate As Decimal = 0.179
'this method will calculate the compound interest for the 
'finance package and calculate payments

Private Sub frmFinancePackage_Load(ByVal sender As System.Object, _
     ByVal e As System.EventArgs) Handles MyBase.Load

txtGrossTotal.Text = FormatCurrency(runningCost)

End Sub

Private Sub btnCalculate_Click(sender As System.Object, _
         e As System.EventArgs) Handles btnCalculate.Click
'Declaring local variables
Dim NumYears As Integer
Dim GrossTotal As Decimal
Dim PaymentDue As Integer
Dim NetTotal As Decimal

'Assigning a value to the numYears variable based on which radio button is checked 
'If no radio button is checked a value of 0 is passed

If rdoOneYear.Checked Then
    NumYears = 1
ElseIf rdoTwoYears.Checked Then
    NumYears = 2
ElseIf rdoThreeYears.Checked Then
    NumYears = 3
End If

GrossTotal = runningCost


'Assign a value to NetTotal by calling a function findNetTotal
'pass the variables NumYears and GrossTotal
NetTotal = findNetTotal(NumYears, GrossTotal)

'Assign a value to paymentDue based on what payment frequency radio button is checked
'pass a vaule of 0 if no radio button is checked
If rdoWeekly.Checked Then
    PaymentDue = 52 * NumYears
ElseIf rdoMonthly.Checked Then
    PaymentDue = 12 * NumYears
ElseIf rdoQuarterly.Checked Then
    PaymentDue = 4 * NumYears
End If


'Displaying the results

txtInterest.Text = FormatCurrency(NetTotal - GrossTotal)
txtNetTotal.Text = FormatCurrency(NetTotal)
txtPayment.Text = FormatCurrency(NetTotal / PaymentDue)

btnContinue.Enabled = True
End Sub

'这是查找NetTotal的功能

Private Function findNetTotal(ByVal years As Integer, ByVal total As Decimal) As Decimal

'Declare variables for the function
Dim interest As Decimal
Dim months As Integer = years * 12

'Use a loop to find the net total based on compound interest for the number of years
'compound interst is calculated per month
'return the net total

For i As Integer = 1 To months
    interest = total * (interestRate / 12)
    total += interest
Next
Return total
End Function
End Class

Answer 1

我认为您的代码可能是正确的，但您的测试可能不是。当我将以下公式*放入Excel时，它给出了与findNetTotal函数相同的值。

= 200 *（1+（0.179 / 12））^ 12 给出238.8882

当我将代码（常量和findNewTotal）粘贴到本地项目中时，调用findNewTotal为1年，200为总，给出238.88815 ....作为输出，与Excel匹配。

那么，为什么你认为17.9％应该拿出35.80而不是38.89？

*公式来自MS网站的复利：http://support.microsoft.com/kb/141695

利率根据需要以不同的百分比工作

1 个答案: