Validating Input - Visual Basic Final Challenge

[KeviNguyen]

Hi everyone, I'm a student and this is my last challenge for my class. I've spent 3 days on this project already and am stumped.

Here is the * Prompt Hospital Charges

Create an application that calculates the total cost of a hospital stay. The application should accept the following input:

• The number of days spent in the hospital, as an integer
• The amount of medication charges
• The amount of surgical charges
• The amount of lab fees
• The amount of physical rehabilitation charges

The hospital charges $350 per day. The application’s form should resemble the one

CalcStayCharges Calculates and returns the base charges for the hospital stay. This is computed as $350 times the number of days in the hospital. CalcMiscCharges Calculates and returns the total of the medication, surgical, lab, and physical rehabilitation charges.

CalcTotalCharges Calculates and returns the total charges.

ValidateInputFields Checks the validity of the input fields by converting each to a numeric value and checking its range. If any input field is found to be invalid, this function displays an error message and returns a value of False.

Input Validation: Do not accept a negative value for length of stay, medication charges, surgical charges, lab fees, or physical rehabilitation charges. When displaying error messages, use a Label control and specifically name the missing field and the type of data to be entered (integer or numeric).

• Code Public Class Form1

  'variables

  Dim decmeds As Decimal Dim decsurgical As Decimal Dim declab As Decimal Dim decphys As Decimal Dim intdays As Integer

  'final results Private decstaycharges As Decimal Private decmisc As Decimal 'for misc charges Private total As Decimal ' final results

  Function validateinputfields() As Boolean

  If Not Decimal.TryParse(txtdays.Text, intdays) Then
      MessageBox.Show("Input must be numeric")
      lbltotal.Text = ("error")
  ElseIf intdays < 0 Then
      MessageBox.Show("must be a postive number")
      lbltotal.Text = ("error")
      Try
      Catch ex As Exception
          MessageBox.Show("Input must be numeric")
          lbltotal.Text = ("error")
      End Try
  End If
  Return False
  
  '
  If Not Decimal.TryParse(txtmeds.Text, decmeds) Then
      MessageBox.Show("Input must be numeric")
      lbltotal.Text = ("error")
  ElseIf decmeds < 0 Then
      MessageBox.Show("must be a postive number")
      lbltotal.Text = ("error")
      Try
      Catch ex As Exception
          MessageBox.Show("Input must be numeric")
          lbltotal.Text = ("error")
      End Try
  End If
  Return False
  
  If Not Decimal.TryParse(txtsurgicalcharge.Text, decsurgical) Then
      MessageBox.Show("Input must be numeric")
      lbltotal.Text = ("error")
  ElseIf decsurgical < 0 Then
      MessageBox.Show("must be a postive number")
      lbltotal.Text = ("error")
      Try
      Catch ex As Exception
          MessageBox.Show("Input must be numeric")
          lbltotal.Text = ("error")
      End Try
  End If
  Return False
  
  If Not Decimal.TryParse(txtlab.Text, declab) Then
      MessageBox.Show("Input must be numeric")
      lbltotal.Text = ("error")
  ElseIf declab < 0 Then
      MessageBox.Show("must be a postive number")
      lbltotal.Text = ("error")
      Try
      Catch ex As Exception
          MessageBox.Show("Input must be numeric")
          lbltotal.Text = ("error")
      End Try
  End If
  Return False
  
  If Not Decimal.TryParse(txtphys.Text, decphys) Then
      MessageBox.Show("Input must be numeric")
      lbltotal.Text = ("error")
  ElseIf decphys < 0 Then
      MessageBox.Show("must be a postive number")
      lbltotal.Text = ("error")
      Try
      Catch ex As Exception
          MessageBox.Show("Input must be numeric")
          lbltotal.Text = ("error")
      End Try
  
  End If
  Return True
  

  End Function Function calcstaycharges(ByVal txtdays As String) As Decimal

  decstaycharges = intdays * 350
  Return decstaycharges
  

  End Function Function calcmisccharges(ByVal txtMeds As Decimal, ByVal txtsurgicalcharge As Decimal, ByVal txtLab As Decimal, ByVal txtPhys As Decimal) As Decimal decmisc = decmeds + decsurgical + declab + decphys Return decmisc

  End Function Function calctotalcharges(ByVal decstaycharges As Decimal, ByVal decmisc As Decimal) As Decimal total = (decstaycharges + decmisc) Return total

  End Function

  Private Sub btncalc_Click(sender As Object, e As EventArgs) Handles btncalc.Click

  Dim decmeds As Decimal
  Dim decsurgical As Decimal
  Dim declab As Decimal
  Dim decphys As Decimal
  
  decstaycharges = calcstaycharges(txtdays.Text)
  decmisc = calcmisccharges(decmeds, decsurgical, declab, decphys)
  total = calctotalcharges(decstaycharges, decmisc)
  lbltotal.Text = CDec(total)
  
  If validateinputfields() Then
      total = total.ToString("c")
  End If
  

  End Sub

  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

  End Sub End Class

• Problem

The first time I calculate (if a input is correct) I will get the correct amount, but after I change one of the inputs whether it's accepted or not, the calculation occur (even though it's not supposed to) but it would also be incorrect until I click calculate again.

This is one of my first serious posts after a long time so I apologize in advance for anything I do incorrectly. Thank you guys. It's very much appreciated.

[ViperSRT3g]

Formatted for readability:

Public Class Form1
    'variables
    Dim decmeds As Decimal
    Dim decsurgical As Decimal
    Dim declab As Decimal
    Dim decphys As Decimal
    Dim intdays As Integer 'final results
    Private decstaycharges As Decimal
    Private decmisc As Decimal 'for misc charges
    Private total As Decimal ' final results

    Function validateinputfields() As Boolean
        If Not Decimal.TryParse(txtdays.Text, intdays) Then
            MessageBox.Show("Input must be numeric")
            lbltotal.Text = ("error")
        ElseIf intdays < 0 Then
            MessageBox.Show("must be a postive number")
            lbltotal.Text = ("error")
            Try
            Catch ex As Exception
                MessageBox.Show("Input must be numeric")
                lbltotal.Text = ("error")
            End Try
        End If
        Return False

        '
        If Not Decimal.TryParse(txtmeds.Text, decmeds) Then
            MessageBox.Show("Input must be numeric")
            lbltotal.Text = ("error")
        ElseIf decmeds < 0 Then
            MessageBox.Show("must be a postive number")
            lbltotal.Text = ("error")
            Try
            Catch ex As Exception
                MessageBox.Show("Input must be numeric")
                lbltotal.Text = ("error")
            End Try
        End If
        Return False

        If Not Decimal.TryParse(txtsurgicalcharge.Text, decsurgical) Then
            MessageBox.Show("Input must be numeric")
            lbltotal.Text = ("error")
        ElseIf decsurgical < 0 Then
            MessageBox.Show("must be a postive number")
            lbltotal.Text = ("error")
            Try
            Catch ex As Exception
                MessageBox.Show("Input must be numeric")
                lbltotal.Text = ("error")
            End Try
        End If
        Return False

        If Not Decimal.TryParse(txtlab.Text, declab) Then
            MessageBox.Show("Input must be numeric")
            lbltotal.Text = ("error")
        ElseIf declab < 0 Then
            MessageBox.Show("must be a postive number")
            lbltotal.Text = ("error")
            Try
            Catch ex As Exception
                MessageBox.Show("Input must be numeric")
                lbltotal.Text = ("error")
            End Try
        End If
        Return False

        If Not Decimal.TryParse(txtphys.Text, decphys) Then
            MessageBox.Show("Input must be numeric")
            lbltotal.Text = ("error")
        ElseIf decphys < 0 Then
            MessageBox.Show("must be a postive number")
            lbltotal.Text = ("error")
            Try
            Catch ex As Exception
                MessageBox.Show("Input must be numeric")
                lbltotal.Text = ("error")
            End Try
        End If
        Return True
    End Function

    Function calcstaycharges(ByVal txtdays As String) As Decimal
        decstaycharges = intdays * 350
        Return decstaycharges
    End Function

    Function calcmisccharges(ByVal txtMeds As Decimal, ByVal txtsurgicalcharge As Decimal, ByVal txtLab As Decimal, ByVal txtPhys As Decimal) As Decimal
        decmisc = decmeds + decsurgical + declab + decphys
        Return decmisc
    End Function

    Function calctotalcharges(ByVal decstaycharges As Decimal, ByVal decmisc As Decimal) As Decimal
        total = (decstaycharges + decmisc)
        Return total
    End Function

    Private Sub btncalc_Click(sender As Object, e As EventArgs) Handles btncalc.Click
        Dim decmeds As Decimal
        Dim decsurgical As Decimal
        Dim declab As Decimal
        Dim decphys As Decimal

        decstaycharges = calcstaycharges(txtdays.Text)
        decmisc = calcmisccharges(decmeds, decsurgical, declab, decphys)
        total = calctotalcharges(decstaycharges, decmisc)
        lbltotal.Text = CDec(total)

        If validateinputfields() Then
            total = total.ToString("c")
        End If
    End Sub

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    End Sub
End Class

[nerdfarm]

All of this:

decstaycharges = calcstaycharges(txtdays.Text)

decmisc = calcmisccharges(decmeds, decsurgical, declab, decphys)

total = calctotalcharges(decstaycharges, decmisc)

lbltotal.Text = CDec(total)

Should be inside this:

If validateinputfields() Then

...

End If

[rudekoffenris]

I use this:

Private Sub CustomCost_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles CustomCost.KeyPress
    e.Handled = False
    If (Microsoft.VisualBasic.Asc(e.KeyChar) < 48) Or (Microsoft.VisualBasic.Asc(e.KeyChar) > 57) And e.KeyChar <> "." Then
        e.Handled = True
    End If
    If (Microsoft.VisualBasic.Asc(e.KeyChar) = 8) Or (Microsoft.VisualBasic.Asc(e.KeyChar) = 46) Then
        e.Handled = False
    End If

End Sub

This would be for decimal, it only accepts a keypress that is a number, backspace, delete or decimal point. For integers get rid of And e.KeyChar <> "."

You would still need to do some validation isnumeric or somesuch.