CODEWITHSUNDEEP
vb.net
user2976157
user2976157

Reputation: 21

Case Statement not working with String Literals

Hi all I am trying to learn VB and am having trouble with some code I am using. I would like my program to output a specific number based on if a check box is checked using case statements but my code is not working.

Public Class frmBTPW

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

End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles btncalc.Click
    Dim dblhdr As Double
    Dim dblfdr As Double
    Dim dbltdr As Double

    dblhdr = 24
    dblfdr = 35
    dbltdr = 50

    Select Case "Power Wash Rental"
        Case "Half Day Rental"

            If chkhd.Checked = True Then
                txtrc.Text = "poop"

            End If


        Case "Full Day Rental"

            If chkFD.Checked = True Then
                txtrc.Text = dblfdr

            End If
    End Select





End Sub

Private Function Button1_Click() As CheckBox
    Throw New NotImplementedException
End Function

End Class

Help would be greatly appreciated.My code isn't outputting anything in the text-box.

Upvotes: 0

Views: 223

Answers (4)

вʀaᴎᴅᴏƞ вєнᴎєƞ
вʀaᴎᴅᴏƞ вєнᴎєƞ

Reputation: 1678

As others have stated your Case statement isn't working because you are using string literals to compare "Power Wash Rental" to "Half Day Rental" which will always be false. Plutonix was also correct in saying that a ComboBox for the rental duration should be used. The only reason not to be is if you were calculating cumulative rental days/amounts; however in that situation you should be using some sort of NumericUpDown for your multiplier against a time duration.

Here is an example that should help you get started. You could make the structure into a type of keyed collection or make it a wrapper class for a dictionary object which would make be easier to use in code. The following may not be exactly plug-and-play with your project, however it should help give you some ideas on how to handle the situation. 

Option Strict On
Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.ComboBox1.Items.AddRange({PowerWashRentals.halfDayText, PowerWashRentals.FullDayText, PowerWashRentals.TwoDayText})
        AddHandler ComboBox1.SelectedValueChanged, AddressOf Me.ComboBox1_SelectedChanged    
    End Sub

    Private Sub ComboBox1_SelectedChanged(sender As Object, e As EventArgs)
        Dim cBox As ComboBox = DirectCast(sender, ComboBox)

        Select Case cBox.SelectedItem.ToString
            Case PowerWashRentals.halfDayText
                Label1.Text = PowerWashRentals.HalfDayPrice.ToString
            Case PowerWashRentals.FullDayText
                Label1.Text = PowerWashRentals.FullDayPrice.ToString
            Case PowerWashRentals.TwoDayText
                Label1.Text = PowerWashRentals.TwoDayPrice.ToString
        End Select
    End Sub
End Class

Public Structure PowerWashRentals
    Public Const HalfDayPrice As Double = 24
    Public Const FullDayPrice As Double = 35
    Public Const TwoDayPrice As Double = 50

    Public Const halfDayText As String = "Half Day Rental"
    Public Const FullDayText As String = "Full Day Rental"
    Public Const TwoDayText As String = "Two Day Rental"
End Structure

Upvotes: 0

D. Kermott
D. Kermott

Reputation: 1673

This is a simple way to do it.

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
   chkhd.tag = 24 ' store values in the check boxes
   chkfd.tag = 35 ' using the tag property 
   chktd.tag = 50 ' and later add up the values
End Sub 

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles btncalc.Click
   dim total as double = 0
   total += IF(chkhd.checked, cdbl(chkhd.tag), 0)
   total += IF(chkfd.checked, cdbl(chkfd.tag), 0)
   total += IF(chktd.checked, cdbl(chktd.tag), 0)
   msgbox(total)
End Sub

However, I think you might want radio buttons instead of checkboxes. Checkboxes can all be checked. Radio buttons can only have one at a time.

This solution allows you to keep your price with the checkbox -- you could do this in the form designer instead of form load.

Upvotes: 1

PaulOTron2000
PaulOTron2000

Reputation: 1225

Beyond case statements, respectfully I think you should read up on the distinction between a literal value and a variable. "Power Wash Rental" is nothing more than a series of characters, AKA a string: (In this case "P" followed by "o" etc.) Likewise, "Half Day Rental" is a series of characters, "H" followed by "a" etc.)

"Power Wash Rental" is a literal string. So is ""Half Day Rental" and of course they will never match.

Whereas: 

Dim A as string
A = TextBox1.text

Now, A is a variable. It is a string which contains whatever series of characters (text) is typed into the textbox.

Upvotes: 1

Trevor
Trevor

Reputation: 8004

I would recommend reading up on Case Statements. Currently you will never get anywhere as your using a string to what, nothing. You also do not need a case for this... Also if the first condition is true and the last one is as well, the last one win's for setting the text, didn't know if you had this there for a reason or not?

 If chkhd.Checked = True Then
   txtrc.Text = "poop"
 End If
 If chkFD.Checked = True Then
   txtrc.Text = dblfdr
 End If

Upvotes: 0

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