Моя программа не будет вычислять итоговые значения

Question

Я делаю школьный проект, и я должен создать базу данных, которая будет вычислять арендуемое оборудование. Он должен рассчитать количество дней и рассчитать общую сумму за весь счет. Моя программа не вычисляет. Вот код программы:

Public Class VandemanForm 

    ' Declare module level variables and constants. 

    Const FLOOR_POLISHER_PER_DAY_Decimal As Decimal = 25.95D 
    Const CARPET_STRETCHER_PER_DAY_Decimal As Decimal = 17.95D 
    Const NAIL_GUN_PER_DAY_Decimal As Decimal = 11.49D 
    Const AIR_COMPRESSOR_PER_DAY_Decimal As Decimal = 19.95D 

    'This stores the price per day 

    Private FloorPolisherPerDayDecimal As Decimal = 0D 
    Private CarpetStretcherPerDayDecimal As Decimal = 0D 
    Private NailGunPerDayDecimal As Decimal = 0D 
    Private AirCompressorPerDayDecimal As Decimal = 0D 

    'This stores the number of days entered 

    Private FloorPolisherDaysDecimal As Decimal = 0D 
    Private CarpetStretcherDaysDecimal As Decimal = 0D 
    Private NailGunDaysDecimal As Decimal = 0D 
    Private AirCompressorDaysDecimal As Decimal = 0D 

    Private Sub CalculateButton_Click(ByVal sender As _ 
     System.Object, ByVal e As System.EventArgs) _ 
     Handles CalculateButton.Click 

     ' Declare procedure level variables to hold data 

     Dim FloorPolisherTotalDecimal As Decimal = 0D 
     Dim CarpetStretcherTotalDecimal As Decimal = 0D 
     Dim NailGunTotalDecimal As Decimal = 0D 
     Dim AirCompressorTotalDecimal As Decimal = 0D 
     Dim GrandTotalDecimal As Decimal = 0D 

     ' Check to see that data has been entered and in 
     ' the correct format before calculating totals. 

     If FirstNameTextBox.Text <> vbNullString And _ 
      LastNameTextBox.Text <> vbNullString Then 
     Else 
      MessageBox.Show("First name and last name must be entered.", _ 
         "Customer name error.", MessageBoxButtons.OK, _ 
         MessageBoxIcon.Error) 
      FirstNameTextBox.Focus() 
     End If 

     ' Check for an entry in the equipment days text boxes and if not 
     ' empty, go on to calculate 

     Try 

      If FloorPolisherDaysTextBox.Text <> vbNullString Then 
       FloorPolisherDaysDecimal = Decimal.Parse(FloorPolisherDaysTextBox.Text) 
       FloorPolisherTotalDecimal = FloorPolisherDaysDecimal * FloorPolisherPerDayDecimal 

      End If 

      If CarpetStretcherDaysTextBox.Text <> vbNullString Then 
       CarpetStretcherDaysDecimal = Decimal.Parse(CarpetStretcherDaysTextBox.Text) 
       CarpetStretcherTotalDecimal = CarpetStretcherDaysDecimal * CarpetStretcherPerDayDecimal 
      End If 

      If NailGunDaysTextBox.Text <> vbNullString Then 
       NailGunDaysDecimal = Decimal.Parse(NailGunDaysTextBox.Text) 
       NailGunTotalDecimal = NailGunDaysDecimal * NailGunPerDayDecimal 
      End If 

      If AirCompressorDaysTextBox.Text <> vbNullString Then 
       AirCompressorDaysDecimal = Decimal.Parse(AirCompressorDaysTextBox.Text) 
       AirCompressorTotalDecimal = AirCompressorDaysDecimal * AirCompressorPerDayDecimal 

      End If 

      GrandTotalDecimal = FloorPolisherTotalDecimal + CarpetStretcherTotalDecimal _ 
       + NailGunTotalDecimal + AirCompressorTotalDecimal 

     Catch ex As Exception 
      MessageBox.Show("The days of the equipment rental must be numeric if entered.", 
          "Data Entry Error", MessageBoxButtons.OK, MessageBoxIcon.Error) 

     End Try 

     ' Display the results and format as currency 
     FloorPolisherSubtotalTextBox.Text = FloorPolisherTotalDecimal.ToString("C") 
     CarpetStretcherSubtotalTextBox.Text = CarpetStretcherTotalDecimal.ToString("C") 
     NailGunSubtotalTextBox.Text = NailGunTotalDecimal.ToString("C") 
     AirCompressorSubtotalTextBox.Text = AirCompressorTotalDecimal.ToString("C") 

     GrandTotalDecimal = FloorPolisherTotalDecimal + CarpetStretcherTotalDecimal _ 
      + NailGunTotalDecimal + AirCompressorTotalDecimal 
     TotalTextBox.Text = GrandTotalDecimal.ToString("C") 


    End Sub 

    Private Sub ExitButton_Click(ByVal sender As _ 
     System.Object, ByVal e As System.EventArgs) _ 
     Handles ExitButton.Click 

     Me.Close() 

    End Sub 

    Private Sub ClearButton_Click(ByVal sender As System.Object, _ 
     ByVal e As System.EventArgs) Handles ClearButton.Click 

     ' Clear all text boxes, Return the focus to the first name field. 

     FirstNameTextBox.Clear() 
     LastNameTextBox.Clear() 
     FloorPolisherDaysTextBox.Clear() 
     CarpetStretcherDaysTextBox.Clear() 
     NailGunDaysTextBox.Clear() 
     AirCompressorDaysTextBox.Clear() 
     FloorPolisherSubtotalTextBox.Clear() 
     CarpetStretcherSubtotalTextBox.Clear() 
     NailGunSubtotalTextBox.Clear() 
     AirCompressorSubtotalTextBox.Clear() 
     TotalTextBox.Clear() 

     'Return focus to the first name textbox 
     FirstNameTextBox.Focus() 

    End Sub 

    Private Sub OrderGroupBox_Enter(sender As System.Object, e As System.EventArgs) Handles FloorToolOrderGroupBox.Enter 

    End Sub 
End Class 

Answer 1

Я думаю, что вы могли бы сделать так, чтобы положить в тарифы для различных пунктов. Для них нет места в форме, а переменные класса содержат значения нуля.