vb.net - Visual Basic 贷款利息和本金计算器

Question

我试图让程序输出支付给 5000 美元贷款的本金和支付的利息。没有输入已经全部声明。

    Private Sub calButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles calButton.Click
    Dim monthlyPayments As Double
    Dim bloanTotal As Double = 5000
    Dim rate As Double = 0.005
    Dim interest As Double
    Dim toPrincipal As Double
    Dim toInterest As Double
    Dim counter As Integer

    Do
        'calculate the montly payments.
        monthlyPayments =
    Financial.Pmt(0.06 / 12, 12, 5000)
        TextBox1.Text = monthlyPayments.ToString("C2")

        counter = counter + 1        'add one to the counter 
        interest = bloanTotal * rate    'calculate interest rate from payment that will only count as interest
        toInterest = monthlyPayments - interest 'amount of monthly payment going towards interest
        toPrincipal = monthlyPayments - toInterest ' amount of monthly payment going towards principal
        bloanTotal = bloanTotal - toPrincipal 'new balance after deducing principal from begining balance

        Label2.Text = toPrincipal.ToString & "      " &
                      toInterest.ToString &
                      ControlChars.NewLine ' concatinate principal and interest strings and create a new line


        If counter = 12 Then 'exit loop once counter has reached 12 and loan amount has reached zero
            Exit Do
        End If
    Loop
End Sub

Answer 1

我相信你的问题是Financial.Pmt函数返回一个负数。因为这是会计，所以你告诉函数你收到了 5000 笔贷款（正数），你将付款（负数）。如果你这样做

monthlyPayments = Math.Abs(Financial.Pmt(0.06 / 12, 12, 5000))

那么你的计算应该会成功。