Coding Monthly Sales Taxes on Visual Studios

Question

i really need help with this code it’s my first real full code and i need to be able to enter three numbers, click compute, and then three new numbers are supposed to appear from the bottom. can someone help me. nothings coming up.

Answer 1

Hi

OK, here is a version of your code that seems to work. The main problem was that you didn't actually assign the results to the desired textboxes to show them. There were other small errors too.
I have also shown a way to avoid errors from user inputs. In your code, if the Compute button is pressed and any of the three input boxes are either empty, or contain non numeric characters [space char is a typical error producing input], then the code will break when trying to convert to a decimal number. The Function will not cause an error, instead it will return a numeric zero value so calculations can continue (and produce the wrong answer), but can then be corrected by the user and recalculated.
NOTE: the code in a Code Block so copy/paste is easy!

NOTE ALSO: in my example, the results textboxes are named TextBox1, TextBox2 and TextBox3

Option Strict On
Option Explicit On
Public Class Form1
 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
 ' compute
 ' if blank (or non-numeric) ERROR
 Dim dectotalsales As Decimal = CDec(txttosales.Text)

 ' if blank (or non-numeric) NO ERROR
 ' because the function is used.
 Dim deccountyrate As Decimal = GetDecimal(txtcountyrate.Text)

 ' if blank (or non-numeric) ERROR
 Dim decstaterate As Decimal = CDec(txtstaterate.Text)

 Dim deccountytax As Decimal = dectotalsales * deccountyrate / 100
 Dim decstatetax As Decimal = dectotalsales * decstaterate / 100
 Dim dectotaltax As Decimal = deccountytax + decstatetax

 ' NOW, put results into etxtboxes
 TextBox1.Text = deccountytax.ToString("C")
 TextBox2.Text = decstatetax.ToString("C")
 TextBox3.Text = (deccountytax + decstatetax).ToString("C")

 End Sub

 Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
 txttosales.Text = String.Empty
 txtcountyrate.Text = String.Empty
 txtstaterate.Text = String.Empty

 TextBox1.Text = String.Empty
 TextBox2.Text = String.Empty
 TextBox3.Text = String.Empty

 End Sub

 Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
 Close()
 End Sub

 ' this function will return a valid number
 ' which will be zero if string is not a
 ' valid number.
 Function GetDecimal(s As String) As Decimal
 Dim v As Decimal = 0.0D
 If Decimal.TryParse(s, v) Then Return v
 Return 0.0D
 End Function
End Class