VBモーゲージ・カルキュレータが正しい出力を表示しない

Question

私の教授は、私たちにサブ手続きを使って住宅ローン電卓を作成するよう要求しています。私はサブのやByVal/ByRefを使わずに、このボタンをクリックするだけでこのタスクを完了できました。しかし、私はそれをいくつかの異なる関数とサブミットに分割すると、私はボタンをクリックして計算するとエラーが0になりますが、3つの表示出力はすべて0です。私はそれが私の関数calcブロックまたは私のbtnCalculate_Click Sub。

Public Class frmMortgage 

    Dim annualRateOfInterest, monthlyPayment, begBalance As Double 'Declaring variables 
    Dim intForMonth, redOfPrincipal, endBalance As Double 

    Private Sub btnCalculate_Click(sender As Object, e As EventArgs) Handles btnCalculate.Click 

     Call getInput(annualRateOfInterest, monthlyPayment, begBalance) 

     Call displayOutput(intForMonth, redOfPrincipal, endBalance) 

    End Sub 

    Sub getInput(ByVal annualRateOfInterests As Double, ByVal monthlyPayment As Double, ByVal begBalance As Double) 'Values input into txt boxes 
     annualRateOfInterest = CDbl(txtInterest.Text)/100 'Change number entered into a percentage 
     monthlyPayment = CDbl(txtPayment.Text) 
     begBalance = CDbl(txtBalance.Text) 
    End Sub 

    Function calc(ByVal annualRateOfInterest As Double, ByVal monthlyPayment As Double, ByVal begBalanceintForMonth As Double, ByVal redOfPrincipal As Double, ByVal endBalance As Double) 
     Return intForMonth = (annualRateOfInterest/12) * begBalance 'Take percentage divided by 12 times beginning balance 
     Return redOfPrincipal = monthlyPayment - intForMonth 
     Return endBalance = begBalance - redOfPrincipal 
    End Function 

    Sub displayOutput(ByRef intForMonth As Double, ByRef redOfPrincipal As Double, ByRef endBalance As Double) 
     mtbMonth.Text = CDbl(intForMonth) 'Display the calculated data into correct textboxes. 
     mtbROP.Text = CDbl(redOfPrincipal) 
     mtbEndBalance.Text = CDbl(endBalance) 
    End Sub 

End Class 

Answer 1

私はただ1つをSubにまとめました。

Private Sub btnCalculate_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnCalculate.Click 
    ComputeMortgage(Val(txtInterest.Text), Val(txtPayment.Text), Val(txtBalance.Text)) 
End Sub 

Sub ComputeMortgage(ByVal Interest As Double, ByVal monthlyPayment As Double, ByVal begBalance As Double) 
    annualRateOfInterest = Interest/100 

    'COMPUTATION 
    intForMonth = (annualRateOfInterest/12) * begBalance 'Take percentage divided by 12 times beginning balance 
    redOfPrincipal = monthlyPayment - intForMonth 
    endBalance = begBalance - redOfPrincipal 

    'DISPLAYING 
    mtbMonth.Text = intForMonth 'Display the calculated data into correct textboxes. 
    mtbROP.Text = redOfPrincipal 
    mtbEndBalance.Text = endBalance 

End Sub