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For an assignment I am trying to take code I already have and edit it to use collections instead of module scoped variables. Now I am new to VB, I have a good grasp of the basics but I can not for the life of me figure out how to implement collections and get this to work. I am unsure if I need multiple collections or just 1. Basically this code is calculator which tells you the miles your car has traveled (from the time of purchase) the amount you have paid for fuel, MPG, and other info. I have commented the code but if anyone else needs clarification let me know. Any point in the right direction would be GREATLY appreciated.
Public Class GasD
'*****************************************************************
'* Gas-D v3.0
'* By digink
'* Homework 3
'* Description: This program is a more complex version of homework
'* 2. In this homework the user gets to input the same data as done
'* in homework 2 (price paid, MPG, historical data, etc.) but along
'* with that the user also gets to input the gas tax data based upon
'* the type of fuel they used and also the county in which the fuel
'* was purchased.
'*****************************************************************
'* Module level variables which are used in the Record button
'* to store data for historical computations.
Dim intAccumMiles As Integer = 0
Dim intAccumGallon As Single = 0
Dim intAccumPrice As Single = 0
Dim intAccumTax As Single = 0
Private Sub RecordButton_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnRecord.Click
'********************************************************
'* Loads local variables and also initializes the module
'* level variables for us. This subroutine handles all of
'* the calculations for fill-up and also for the historical
'* data that is stored.
'********************************************************
'* Local fuel and price variables
Dim intGallons As Single
Dim intPricePerGallon As Single
Dim intFillingCost As Single
Dim intMPG As Single
Dim intPircePaidWithTax As Single
'* Variables for local mileage information
Dim intMilesSincePreviousFill As Integer
Dim intStartingMiles As Integer
Dim intCurrentMiles As Integer
'* load local variables with info and clear textboxes
'* Gallons
intGallons = Convert.ToSingle(txtGallonsUsed.Text)
lblCurrentGallon.Text = FormatNumber(intGallons, 1)
txtGallonsUsed.Clear()
'* Price per Gallon
intPricePerGallon = Convert.ToSingle(txtPricePerGallon.Text)
lblShowPrice.Text = FormatNumber(intPricePerGallon, 2)
txtPricePerGallon.Clear()
'* Fill-up date
lblShowDate.Text = dtpDate.Text
'* Starting Miles
intStartingMiles = Convert.ToInt32(txtStartMiles.Text)
'* Current Miles
intCurrentMiles = Convert.ToInt32(txtCurrentMiles.Text)
txtCurrentMiles.Clear()
'* Run calculations and display current values
'* Price paid this fill-up
intFillingCost = intGallons * intPricePerGallon
lblShowPricePaid.Text = FormatNumber(intFillingCost, 2)
'* Calculate and display MPG since last fill up
intMilesSincePreviousFill = intCurrentMiles - intStartingMiles - _
intAccumMiles
intMPG = intMilesSincePreviousFill / intGallons
lblMPG.Text = Format(intMPG, "##0.0")
'* Total taxes paid
intPircePaidWithTax = lbFuelTax.Text * intGallons
lbGasWithTax.Text = _
FormatCurrency(Convert.ToSingle(intPircePaidWithTax))
'* Calculate and display cumulative values and load
'* accum variables
'* Total miles
intAccumMiles = intCurrentMiles - intStartingMiles
lblAccumMile.Text = Format(intAccumMiles, "##,##0.")
'* Total fuel used
intAccumGallon += intGallons
lblTotalFuel.Text = Format(intAccumGallon, "#,##0.0")
'* Total Cost
intAccumPrice += intFillingCost
lblTotalGas.Text = FormatCurrency(intAccumPrice)
'* Long run MPG
intMPG = intAccumMiles / intAccumGallon
lblAccumMPG.Text = Format(intMPG, "##0.0")
'* Long run tax
intAccumTax += intPircePaidWithTax
lbTotalTaxAccum.Text = FormatCurrency(intAccumTax)
End Sub
Private Sub GetTaxes()
'***********************************************************************
'* Sample logic that will calculate the total tax owed per gallon from
'* the two components of the tax used in homework assignments for
'* ISM 3253 Section 01, Fall 2008.
'* Note that this solution is creating a locally scoped variable with
'* the result. The logic would have to be modified to enable the
'* result to be available where needed in the program logic.
'***********************************************************************
Dim sglTaxRate As Single
'* Determine fuel-type tax component
If lbGasType.SelectedIndex = 0 Then '* Gasoline
sglTaxRate = 0.259
'* If the fuel is not gasoline it is Diesel
Else '* Diesel
sglTaxRate = 0.29
End If
'* Add the county component of the tax to the fuel-type component
Select Case lbCounty.Text
Case "Orange"
sglTaxRate += 0.021
Case "Seminole"
sglTaxRate += 0.031
Case "Brevard"
sglTaxRate += 0.021
Case "Osceola"
sglTaxRate += 0.031
Case "Volusia"
sglTaxRate += 0.081
Case "Lake"
sglTaxRate += 0.031
End Select
lbFuelTax.Text = sglTaxRate
End Sub
Private Sub GasD_Load(ByVal sender As System.Object, ByVal e As _
System.EventArgs) Handles MyBase.Load
'*****************************************************************
'* Sets the Selected index of the ListBox gasType to 0, which is
'* the first index. This is to make Gasoline the defealt selection
'* for fuel type when the program is loaded.
'*****************************************************************
lbGasType.SelectedIndex = 0
End Sub
Private Sub lbCounty_SelectedIndexChanged(ByVal sender As _
System.Object, ByVal e As System.EventArgs) Handles _
lbCounty.SelectedIndexChanged
'comment later
Call GetTaxes()
End Sub
Private Sub lbGasType_SelectedIndexChanged(ByVal sender As _
System.Object, ByVal e As System.EventArgs) Handles _
lbGasType.SelectedIndexChanged
'comment later
Call GetTaxes()
End Sub
Private Sub btnExit_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnExit.Click
'*****************************************************************
'* Ends the program when Exit button is pressed or hotkeyed/ESC
'*****************************************************************
Application.Exit()
End Sub
Private Sub ValidateInput(ByRef theTextBox As TextBox, _
ByVal ValidationString As String)
'*******************************************************************************
'* Receives a text box control by reference and a validation string
'* Loops through each character in the text box .Text property to ensure
'* that the character exists in the validation string.
'* Builds an intermediate string of valid characters found in the text box
'* but does not add invalid characters to the intermediate string.
'* Replaces the text box .Text property with the intermediate string
'* Also checks to see if the text property is a zero length string after
'* validation and replaces the string with a zero if so.
'* Also strips any leading zeros from the text property if there is more than
'* one digit
'*******************************************************************************
Dim x As Integer
Dim strNew As String = ""
'* Review all characters in the passed text box to ensure that they are
'* numeric(digits)
'* Loop through all characters and pass numeric digits to a new string
For x = 0 To Len(theTextBox.Text) - 1
'* Test for numeric character. True result means character is numeric.
If InStr(ValidationString, theTextBox.Text.Substring(x, 1)) > 0 Then
strNew += theTextBox.Text.Substring(x, 1)
Else '* Character not numeric
Beep() '* Warn the user
End If
Next
'* Display a zero if no legal quantity has been entered
If strNew.Length = 0 Then
strNew = "0"
End If
'* Remove leading zero if present. (Since this code will run on each
'* keypress there can only be one leading zero at a time.)
If Len(strNew) > 1 And strNew.Substring(0, 1) = "0" Then
strNew = strNew.Substring(1)
End If
'* Update Qty text box with numeric value
theTextBox.Text = strNew
End Sub
Private Sub txtStartMiles_TextChanged(ByVal sender As _
System.Object, ByVal e As System.EventArgs) Handles _
txtStartMiles.TextChanged
'comment later
Call ValidateInput(txtStartMiles, "0123456789")
End Sub
Private Sub txtCurrentMiles_TextChanged(ByVal sender As _
System.Object, ByVal e As System.EventArgs) Handles _
txtCurrentMiles.TextChanged
'comment later
Call ValidateInput(txtCurrentMiles, "0123456789")
End Sub
Private Sub txtGallonsUsed_TextChanged(ByVal sender As _
System.Object, ByVal e As System.EventArgs) Handles _
txtGallonsUsed.TextChanged
'comment later
Call ValidateInput(txtGallonsUsed, "0123456789.")
End Sub
Private Sub txtPricePerGallon_TextChanged(ByVal sender As _
System.Object, ByVal e As System.EventArgs) Handles _
txtPricePerGallon.TextChanged
'comment later
Call ValidateInput(txtPricePerGallon, "0123456789.")
End Sub
End Class
Edited by Jaan, 19 October 2008 - 09:37 PM.
Please use code tags when you're posting your codes!
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