'学习心得

'运算符的优先级

'变量名的制定：g（是否是全局）+数据类型+变量=变量名；gdblName

' AcceptButton Property of the Form specifies this button.When the user press the Enter key or clicks the default button on a form that has the AcceptButton property set.

'



'MonthlyPayment = (InterestRate*(1+InterestRate)^NumberOfPayments)/((1+InterestRate)^NumberOfPayments-1)*LoanAmount 这个在   “Pmt Founction ”  里面有

'Format Function 将日期，时间等转换成专用的格式





Option Strict On

Public Class Form1

    'Purpose:       This project calculates the monthly payment:

    '               a loan based on loan amount,interest rate(利率),'               



    Dim gdblMonths As Double = 60.0

    Const MaximumLoanAllowed As Integer = 25000







    Private Sub Form1_Load(ByVal sender As Object,ByVal e As System.EventArgs) Handles Me.Load

        nudLoanAmount.Maximum = MaximumLoanAllowed

    End Sub



    Private Sub btnReset_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles btnReset.Click

        nudLoanAmount.Value = 0

        nudRate.Value = 5

        radFiveYears.Checked = True

        txtMonthlyPayment.Text = "$0.00"

    End Sub



    Private Sub radTwoYears_CheckedChanged(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles radTwoYears.CheckedChanged

        gdblMonths = 24.0

    End Sub



    Private Sub radFiveYears_CheckedChanged(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles radFiveYears.CheckedChanged

        gdblMonths = 12.0 * 5

    End Sub



    Private Sub radSixYears_CheckedChanged(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles radSixYears.CheckedChanged

        gdblMonths = 12.0 * 6

    End Sub



    Private Sub btnComputePayment_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles btnComputePayment.Click

        Dim dblRate,dblMonths,dblPayment As Double

        Dim dblLoanAmount As Double,strPayment As String

        dblRate = (Convert.ToDouble(nudRate.Value) / 100.0) / 12.0

        dblLoanAmount = Convert.ToDouble(nudLoanAmount.Value)

        dblPayment = Pmt(dblRate,gdblMonths,-dblLoanAmount)

        strPayment = Format(dblPayment,"c")

        'strPayment = dblPayment.ToString        ' Or use  " convert.tostring(dblPayment) "

        txtMonthlyPayment.Text = strPayment        '显示的是本机的现金符号， 如需更改请用 globlization.currentinfo

    End Sub

End Class