Calculations in VS2008

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Thread: Calculations in VS2008

  1. #1
    Join Date
    Sep 2008

    Calculations in VS2008

    Hi all,

    Having a little trouble doing some calculations in VS2008 i am putting figures on a daily basis so not all the text boxes will have a figure in them have linked to a save button on the form but would like to have it that once each text box has lost focus it will update the total in TxtTotalIncome.Text.

    text box 1 has 12 once lost focus total will have 12
    text box 2 has 12 once lost focus total will have 24 (text box 1 + text box 2)

    but when i type in the figures in to the monday and tuesday text boxes it comes up with an error about the missing figure in the wednesday text box and so on.

    Any help will be greatly appriciated.



  2. #2
    Join Date
    Apr 2007
    Sterling Heights, Michigan
    What is the exact error and error number and what code do you have in the Lost Focus event that triggers the calculations?

  3. #3
    Join Date
    Sep 2008
    Hi Hack,

    Conversion from string "" to type 'Integer' is not valid. this is what i get back when i try it the database field was set as currency and i have now changed to number but think it is something to do with it being left blank.

            Dim TotalIncome As Integer
            Dim MondaySales As Integer
            Dim TuesdaySales As Integer
            Dim WednesdaySales As Integer
            Dim ThursdaySales As Integer
            Dim FridaySales As Integer
            Dim SaturdaySales As Integer
            Dim SundaySales As Integer
            TxtTotalIncome.Text = TotalIncome
            MondaySales = MondaySalesTextBox.Text
            TuesdaySales = TuesdaySalesTextBox.Text
            WednesdaySales = WednesdaySalesTextBox.Text
            ThursdaySales = ThursdaySalesTextBox.Text
            FridaySales = FridaySalesTextBox.Text
            SaturdaySales = SaturdaySalesTextBox.Text
            SundaySales = SundaySalesTextBox.Text
            TotalIncome = (MondaySales + TuesdaySales + WednesdaySales)
    This is the code i have in the save_click command button but would like to change this to when i lose focus on the box i have just entered the figure in to it totals it up to total income text box



  4. #4
    Join Date
    Apr 2007
    Sterling Heights, Michigan
    Try this
    MondaySales = Integer.Parse(MondaySalesTextBox.Text)
    TuesdaySales = Integer.Parse(TuesdaySalesTextBox.Text)
    WednesdaySales = Integer.Parse(WednesdaySalesTextBox.Text)
    ThursdaySales = Integer.Parse(ThursdaySalesTextBox.Text)
    FridaySales = Integer.Parse(FridaySalesTextBox.Text)
    SaturdaySales = Integer.Parse(SaturdaySalesTextBox.Text)
    SundaySales = Integer.Parse(SundaySalesTextBox.Text)
    Last edited by Hack; 09-22-2008 at 09:11 AM.

  5. #5
    Join Date
    Sep 2008
    to do the calculation on the lost focus would the formula be put in that decleration?. ie on lose focus mondaysales+tuesdaysales = totalsales.

  6. #6
    Join Date
    Apr 2007
    Sterling Heights, Michigan
    That depends on where it makes the most sense for you and your application.

    TextBox controls do have a Lost Focus event that can be used. The only thing I would put in there would be TotalIncome = (MondaySales + TuesdaySales + WednesdaySales+etc)

    In the Lost Focus event (or something other event that would make sense) I would put the individual variable settings, i.e., MondaySales = Integer.Parse(MondaySalesTextBox.Text) would go in the Lost Focus for the MondaySalesTextBox event. TuesdaySales = Integer.Parse(TuesdaySalesTextBox.Text) would go in the Lost Focus for the TuesdaySalesTextBox event, etc, etc.

    Perhaps what makes the most sense right now isn't readily apparent...that happens. So, just try a few things. First off, make sure the math is working properly. That is number one.

    When that works, then you can fiddle around with where things go and how they will be displayed.

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