Crystal reports [modified] - Visual Basic Discussion Boards

Chandrasekharan P23-Jul-09 19:18

23-Jul-09 19:18

I am displaying the structure members in a listbox. But i need to remove the commented structure members and then display the the other members in the listbox. how do i do that?

Re: Structure in listbox

Christian Graus23-Jul-09 19:35

Christian Graus

23-Jul-09 19:35

What on earth do you mean by commented structure members ? You can change the displaymember in the listbox any time you like.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Re: Structure in listbox [modified][RESOLVED]

Chandrasekharan P23-Jul-09 19:49

Chandrasekharan P

23-Jul-09 19:49

Hey Christian,

i am getting this structure member from a C++ file.

for Ex

Struct{
char name[20];
int l_age;
//int l_salary;
double l_salary;
} Employee;

In this i need to remove int salary and display the rest of the item in the listbox. now i am using InStr to check for "l_" character to select the structure, but how do i avoid the commented members?

modified on Friday, July 24, 2009 2:13 AM

Re: Structure in listbox [modified][RESOLVED]

Christian Graus23-Jul-09 21:46

Christian Graus

23-Jul-09 21:46

You can't remove anything from a struct. You can create a new struct that contains only the members you want, and can initialise itself from an instance of a C++ struct, but I fail to understand why you'd bother.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Outlook Share Add-In setup Working On Vista but not in Window XP

dcdhingra23-Jul-09 16:37

dcdhingra

23-Jul-09 16:37

Hi All

Can any guide me to solve my problem.

i create a setup of outlook VSTO add-in. This setup is not working in Both Winodow XP and Vista.

So my friend suggest me that to write code in Outlook Share Add-In. I again create this share Add-in Setup

and try to run in both machine. But Unfortunately it is not working in XP. And working successful in Vista.

Can any one guide me which file needed to add in XP so my Share Add-in Work on XP also

Regards
DC Confused | :confused:

VB.NET Reports on web service

Rick_Mutimer23-Jul-09 14:04

Rick_Mutimer

23-Jul-09 14:04

Hi,

I am not sure if this is the right location for the question but if not then apologies in advance.

We have a VB2005 web app that dynamically creates a report, renders it as a PDF and saves it to a local location on the server without displaying it to the user. We use rdlc files and the report designer in VS2005 NOT crystal reports. The web site uses ASP.NET 2, IIS7 and 2008. This web app works fine and is reliable. I would like to be able to create this same report and save it locally on the server via a web service call from a windows app. I have taken the code from the web page that performs the job now which does include a report viewer control and put it into a web service and when the local report object tries to add the report data source then it fails with a SOAP exception (null object reference).

I have provided a list of part of the code below. We use an xml file as the data source and load that into a dataset via LoadDDR call. CCA_DataTable1 exists in the local App_Code Folder.

ds4.WriteXml(xmlfile, XmlWriteMode.WriteSchema)
dp4.Dispose()
ds4.Dispose()

Dim rp1 As New Microsoft.Reporting.WebForms.LocalReport
Dim repdatsce = New ReportDataSource("CCA_DataTable1", LoadDDR(xmlfile))

"below is the line that fails with the null exception"

rp1.DataSources.Add(repdatsce)
rp1.ReportPath = "CCA1.rdlc"

etc etc

It may be that a local report requires a report viewer control on a page/form to operate correctly and therefore will not work via a web service (SOAP) call. I would be grateful for any suggestions anyone has to offer to overcome this problem - Thank You in advance.

CharSet issue with CDOSys

Manas Bhardwaj23-Jul-09 10:58

Manas Bhardwaj

23-Jul-09 10:58

I am facing a strange issue when sending a simple text mail with unicode characters.
This is the code which I am using

Set objMessage = CreateObject("CDO.Message")

objMessage.Subject = "another test"
objMessage.From = "sender@test.com"
objMessage.To = "to@test.com"
objMessage.TextBody = "मानस"
objMessage.Send

Till, this point everything looks fine but as soon as I try to specify the charset of the body, the bosy content get corrupted and strage charcters appear in the email.

objMessage.BodyPart.CharSet = "utf-8"

That is, when I add the above line of code it simply does not work.

You may try to reproduce this by copying code into a vbs file.

Anyone has a clue?

Manas Bhardwaj
Please remember to rate helpful or unhelpful answers, it lets us and people reading the forums know if our answers are any good.

Crystal reports [modified]

Ghost_80723-Jul-09 10:24

Ghost_807

23-Jul-09 10:24

I am receiving an error from crystal reports that says i am missing parameters when i tell a report to print directly to a printer.

Here is the calling code.

Dim rdReport As CrystalDecisions.CrystalReports.Engine.ReportDocument
rdReport = PrintDocuments("Xbox Ticket")

'Main Report
rdReport.SetParameterValue("CustomerName", frm.cboCustomerName.Text.ToUpper)
rdReport.SetParameterValue("CustomerPhoneNumber", frm.lblPhoneNumber.Text.ToUpper)

'Details Subreport
rdReport.SetParameterValue("CashierName", Cashier, "Details")
rdReport.SetParameterValue("CustomerName", frm.cboCustomerName.Text.ToUpper, "Details")
rdReport.SetParameterValue("CustomerPhoneNumber", frm.lblPhoneNumber.Text.ToUpper, "Details")
rdReport.SetParameterValue("CopyField", "", "Details")

'Details2 Subreport
rdReport.SetParameterValue("CashierName", Cashier, "Details2")
rdReport.SetParameterValue("CustomerName", frm.cboCustomerName.Text.ToUpper, "Details2")
rdReport.SetParameterValue("CustomerPhoneNumber", frm.lblPhoneNumber.Text.ToUpper, "Details2")
rdReport.SetParameterValue("CopyField", "", "Details2")

rdReport.PrintOptions.PrinterName = My.Settings.ReportPrinter
rdReport.PrintToPrinter(1, True, 0, 0)

PrintDocuments is supposed to create a crystal report, prepopulate some parameter fields and then
return the report to the calling function to be displayed, printed, etc.

Here is the code for that.

Friend Function PrintDocuments(ByVal DocumentName As String) As CrystalDecisions.CrystalReports.Engine.ReportDocument
        Dim rdReport As New CrystalDecisions.CrystalReports.Engine.ReportDocument
        rdReport.Load(frmMain.ProgramDefault.ReportPath & "\" & DocumentName & ".rpt")

        'Set report Logon Info
        Dim LogInfo As CrystalDecisions.Shared.TableLogOnInfo
        Dim crConnectionInfo As New CrystalDecisions.Shared.ConnectionInfo()
        With crConnectionInfo
            .ServerName = DataServer.Server
            .DatabaseName = DataServer.Database
            If DataServer.Security Then
                .IntegratedSecurity = DataServer.Security
            Else
                .IntegratedSecurity = DataServer.Security
                .UserID = DataServer.UserName
                .Password = DataServer.Password
            End If
        End With
        LogInfo = New CrystalDecisions.Shared.TableLogOnInfo
        LogInfo.ConnectionInfo = crConnectionInfo
        Dim crTable As Table
        For i As Integer = 0 To rdReport.Subreports.Count - 1
            For Each crTable In rdReport.Subreports(i).Database.Tables
                crTable.ApplyLogOnInfo(LogInfo)
            Next crTable
        Next
        For Each crTable In rdReport.Database.Tables
            crTable.ApplyLogOnInfo(LogInfo)
        Next
        
        'Look at parameter fields and fill in if found
        Try
            'Sub reports if found
            For i As Integer = 0 To rdReport.Subreports.Count - 1
                'if subreport does not have parameter fields don't worry about it
                If rdReport.Subreports(i).ParameterFields Is Nothing Then Exit For
                For l As Integer = 0 To rdReport.Subreports(i).ParameterFields.Count - 1
                    Select Case rdReport.Subreports(i).ParameterFields(l).Name
                        Case "CompanyName"
                            rdReport.Subreports(i).SetParameterValue("CompanyName", frmMain.ProgramDefault.CompanyName)
                        Case "CompanyStreet"
                            rdReport.Subreports(i).SetParameterValue("CompanyStreet", frmMain.ProgramDefault.CompanyStreet)
                        Case "CompanyCity"
                            rdReport.Subreports(i).SetParameterValue("CompanyCity", frmMain.ProgramDefault.CompanyCity)
                        Case "CompanyState"
                            rdReport.Subreports(i).SetParameterValue("CompanyState", frmMain.ProgramDefault.CompanyState)
                        Case "CompanyZip"
                            rdReport.Subreports(i).SetParameterValue("CompanyZip", frmMain.ProgramDefault.CompanyZip)
                        Case "CompanyPhone"
                            rdReport.Subreports(i).SetParameterValue("CompanyPhone", frmMain.ProgramDefault.CompanyPhone)
                        Case "CompanyFax"
                            rdReport.Subreports(i).SetParameterValue("CompanyFax", frmMain.ProgramDefault.CompanyFax)
                        Case "CompanyWeb"
                            rdReport.Subreports(i).SetParameterValue("CompanyWeb", frmMain.ProgramDefault.CompanyWeb)
                        Case "CashierName"
                            rdReport.Subreports(i).SetParameterValue("CashierName", Cashier)
                    End Select
                Next
            Next
        Catch ex As Exception

        End Try

        'Main reports
        For i As Integer = 0 To rdReport.ParameterFields.Count - 1
            Select Case rdReport.ParameterFields(i).Name
                Case "CompanyName"
                    rdReport.SetParameterValue("CompanyName", frmMain.ProgramDefault.CompanyName)
                Case "CompanyStreet"
                    rdReport.SetParameterValue("CompanyStreet", frmMain.ProgramDefault.CompanyStreet)
                Case "CompanyCity"
                    rdReport.SetParameterValue("CompanyCity", frmMain.ProgramDefault.CompanyCity)
                Case "CompanyState"
                    rdReport.SetParameterValue("CompanyState", frmMain.ProgramDefault.CompanyState)
                Case "CompanyZip"
                    rdReport.SetParameterValue("CompanyZip", frmMain.ProgramDefault.CompanyZip)
                Case "CompanyPhone"
                    rdReport.SetParameterValue("CompanyPhone", frmMain.ProgramDefault.CompanyPhone)
                Case "CompanyFax"
                    rdReport.SetParameterValue("CompanyFax", frmMain.ProgramDefault.CompanyFax)
                Case "CompanyWeb"
                    rdReport.SetParameterValue("CompanyWeb", frmMain.ProgramDefault.CompanyWeb)
                Case "CashierName"
                    rdReport.SetParameterValue("CashierName", Cashier)
            End Select
        Next
        LogInfo = Nothing
        crTable = Nothing
        crConnectionInfo = Nothing

        Return rdReport
    End Function

i'm not sure but it seems that the parameters being set by the calling code are not being set properly.
Here is the original code, i modified it to be reusable in multiple different places but now i am running into this problem

Private Function PrintGameReceipt() As PrintingErrors
     If Not frmMain.ProgramDefault.AllowPrinter Then Return PrintingErrors.OK
     frmMain.Cursor = Cursors.WaitCursor
     Try
         Dim rdReport As New CrystalDecisions.CrystalReports.Engine.ReportDocument
         'rdReport = PrintDocuments("Xbox Ticket")
         'Dim rpath As String = RepPath
         rdReport.Load(frmMain.ProgramDefault.ReportPath & "\" & "Xbox Ticket.rpt")
         Dim LogInfo As CrystalDecisions.Shared.TableLogOnInfo
         Dim crConnectionInfo As New CrystalDecisions.Shared.ConnectionInfo()
         With crConnectionInfo
             .ServerName = DataServer.Server
             .DatabaseName = DataServer.Database
             If DataServer.Security Then
                 .IntegratedSecurity = DataServer.Security
             Else
                 .IntegratedSecurity = DataServer.Security
                 .UserID = DataServer.UserName
                 .Password = DataServer.Password
             End If
         End With

         LogInfo = New CrystalDecisions.Shared.TableLogOnInfo
         LogInfo.ConnectionInfo = crConnectionInfo
         Dim crTable As Table
         For i As Integer = 0 To rdReport.Subreports.Count - 1
             For Each crTable In rdReport.Subreports(i).Database.Tables
                 crTable.ApplyLogOnInfo(LogInfo)
             Next crTable
         Next
         For Each crTable In rdReport.Database.Tables
             crTable.ApplyLogOnInfo(LogInfo)
         Next



         rdReport.SetParameterValue("CompanyName", frmMain.ProgramDefault.CompanyName)
         rdReport.SetParameterValue("CompanyStreet", frmMain.ProgramDefault.CompanyStreet)
         rdReport.SetParameterValue("CompanyCity", frmMain.ProgramDefault.CompanyCity)
         rdReport.SetParameterValue("CompanyState", frmMain.ProgramDefault.CompanyState)
         rdReport.SetParameterValue("CompanyZip", frmMain.ProgramDefault.CompanyZip)
         rdReport.SetParameterValue("CompanyPhone", frmMain.ProgramDefault.CompanyPhone)
         rdReport.SetParameterValue("CompanyFax", frmMain.ProgramDefault.CompanyFax)
         rdReport.SetParameterValue("CompanyWeb", frmMain.ProgramDefault.CompanyWeb)
         rdReport.SetParameterValue("CashierName", Cashier)
         rdReport.SetParameterValue("CustomerName", frm.cboCustomerName.Text.ToUpper)
         rdReport.SetParameterValue("CustomerPhoneNumber", frm.lblPhoneNumber.Text.ToUpper)

         'Details Section
         rdReport.SetParameterValue("CompanyName", frmMain.ProgramDefault.CompanyName, "Details")
         rdReport.SetParameterValue("CompanyStreet", frmMain.ProgramDefault.CompanyStreet, "Details")
         rdReport.SetParameterValue("CompanyCity", frmMain.ProgramDefault.CompanyCity, "Details")
         rdReport.SetParameterValue("CompanyState", frmMain.ProgramDefault.CompanyState, "Details")
         rdReport.SetParameterValue("CompanyZip", frmMain.ProgramDefault.CompanyZip, "Details")
         rdReport.SetParameterValue("CompanyPhone", frmMain.ProgramDefault.CompanyPhone, "Details")
         rdReport.SetParameterValue("CompanyFax", frmMain.ProgramDefault.CompanyFax, "Details")
         rdReport.SetParameterValue("CompanyWeb", frmMain.ProgramDefault.CompanyWeb, "Details")
         rdReport.SetParameterValue("CashierName", Cashier, "Details")
         rdReport.SetParameterValue("CustomerName", frm.cboCustomerName.Text.ToUpper, "Details")
         rdReport.SetParameterValue("CustomerPhoneNumber", frm.lblPhoneNumber.Text.ToUpper, "Details")
         rdReport.SetParameterValue("CopyField", "", "Details")
         'Details2 Section
         rdReport.SetParameterValue("CompanyName", frmMain.ProgramDefault.CompanyName, "Details2")
         rdReport.SetParameterValue("CompanyStreet", frmMain.ProgramDefault.CompanyStreet, "Details2")
         rdReport.SetParameterValue("CompanyCity", frmMain.ProgramDefault.CompanyCity, "Details2")
         rdReport.SetParameterValue("CompanyState", frmMain.ProgramDefault.CompanyState, "Details2")
         rdReport.SetParameterValue("CompanyZip", frmMain.ProgramDefault.CompanyZip, "Details2")
         rdReport.SetParameterValue("CompanyPhone", frmMain.ProgramDefault.CompanyPhone, "Details2")
         rdReport.SetParameterValue("CompanyFax", frmMain.ProgramDefault.CompanyFax, "Details2")
         rdReport.SetParameterValue("CompanyWeb", frmMain.ProgramDefault.CompanyWeb, "Details2")
         rdReport.SetParameterValue("CashierName", Cashier, "Details2")
         rdReport.SetParameterValue("CustomerName", frm.cboCustomerName.Text.ToUpper, "Details2")
         rdReport.SetParameterValue("CustomerPhoneNumber", frm.lblPhoneNumber.Text.ToUpper, "Details2")
         rdReport.SetParameterValue("CopyField", "", "Details2")
         rdReport.PrintOptions.PrinterName = My.Settings.ReportPrinter

         rdReport.PrintToPrinter(1, True, 0, 0)

     Catch ex As Exception
         frmMain.Cursor = Cursors.Default
         Dim vd As New VDialog()
         With vd

             .Buttons = New VDialogButton() {New VDialogButton(VDialogResult.OK)}
             .WindowTitle = "Print Error"
             .MainInstruction = "Print Error"
             .MainIcon = VDialogIcon.Error
             .Content = "Error Printing Receipts"
             .FooterIcon = VDialogIcon.Error
             .FooterText = "Print Error"
             .ExpandedControlText = "Hide Info    "
             .CollapsedControlText = "Show Info    "
             .ExpandedInformation = "Extra Information" & vbCrLf & ControlChars.CrLf & ex.Message
             .ExpandFooterArea = True
             .ExpandedByDefault = False
             .Show()
         End With
         WriteToEventLog("Error Printing Receipts (Game Form Class): " & vbCrLf & ex.Message, , EventLogEntryType.Error, , 227)
         Return PrintingErrors.BadData
     End Try
     frmMain.Cursor = Cursors.Default
     Return PrintingErrors.OK
 End Function

Any help would be greatly appreciated.

modified on Friday, July 24, 2009 9:43 AM

How to access the textbox data embedded in a datalist

MacIntyre23-Jul-09 9:01

MacIntyre

23-Jul-09 9:01

First this app is an intranet WebForms app.
I have displayed bond data in a datalist with additional textboxes in the datalist grid for data entry. I'm actually looking for a better solution than the one that is currently implemented.
Currnetly: textbox1 is txtQty, textbox2 is txtRate, label1 is lblTotal and button1 is btnCompute. The user enters data in txtQty and txtRate click on btnCompute thus invoke datalist_ItemCommand and retrieve the txtQty & txtRate using the .FindCommand for the current row, then compute the lblTotal and move to the next row. This subroutine gets access to "byval e as System.Web.UI.WebControls.DatalistItemEventArgs" which makes the current row available and life is great, except the dataentry operator has to click the compute button.
I would like to get rid of the button and set up the app to use the OnTextChange Event of the textbox. this is a problem because it uses "byval e as System.EventArgs" for its argument and the current datalist row is not available.

Can anybody show me how to get the current row of the datalist for the textbox that triggered the OnTextChange event?
Thanks, Chuck

Hi there. Looking for help on a vb project.

malcomhfc23-Jul-09 3:27

malcomhfc

23-Jul-09 3:27

Hi there Vb community, im looking for help or an example for the following:

Im looking to create a program that starts up with user login, once users login they would be taken to the latest news etc. Using a tab control or something similar the user can click on mail/jobs specific to that user only.

If your slightly confused, i'd like something like this for employees.

Any help or advise would be great thanks,

Malcom

Re: Hi there. Looking for help on a vb project.

David Mujica23-Jul-09 3:38

David Mujica

23-Jul-09 3:38

Sounds more like a corporate Portal than a VB (windows) applicaiton.

Before you go and build something, take a look at Dot Net Nuke (DNN).
http://www.dotnetnuke.com/[^]

Take the time to learn about it and you will be amazed at what you get for free! Big Grin | :-D

I implemented it at my previous company and it works really well.

david

Re: Hi there. Looking for help on a vb project.

DoctorMick23-Jul-09 5:36

DoctorMick

23-Jul-09 5:36

Sounds more like an assignment to me.

Re: Hi there. Looking for help on a vb project.

Jabbar_espania2-Aug-09 11:03

Jabbar_espania

2-Aug-09 11:03

Hi if you are familiar with Visual basic then it's so easy to creat that kind of software .
At first your must to know all atribute . Make a design of data base
E-R diagram depand on your requrement.
First : you design the diagram and make relation with all entity (
Entity-Relationship Model )
Second : Make form depand on those table you made and relationship of model ( You must to make a table of user name and password and make relation with users )

Then it will be more easy.

If You want source code or if you want sample Please write would try to reply you as soon as possible

Good luck

Re: Hi there. Looking for help on a vb project.

malcomhfc8-Aug-09 8:12

malcomhfc

8-Aug-09 8:12

Thanks for replying, i managed to get help. Thanks again,

Malcom

Microsoft Outlook: VBA Syntax Errors in Trying to Search for Recipients in E-Mail Message Body

axla22-Jul-09 19:59

axla

22-Jul-09 19:59

I've looked at several examples (not the database piece yet for capturing the "Yes" instances) and put together the code listed below. In a prior version of code also in the ItemSend Object the user is presented with the message box like I want and if they select "No" the E-Mail message is not sent.

However, when I tried to modify the code (see below) I get the Microsoft VB error:
"Run-time error '424' Object Required

Can someone help me correct my code statement and also let me know if I have the correct syntax for searching the body of the E-Mail message. I created a test E-Mail message with "Joe" in the body of the message. If I can't figure out the database piece, is the only option I have hard coding the names of all the restricted employees?

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean)
Dim olMail As Outlook.MailItem
Set olMail = olapp.CreateItem(olMailItem)
Dim blnExecute As Boolean

If InStr(olMail.Body, "Joe") <> 0 Then

blnExecute = CBool(MsgBox("You are sending " & _
"or forwarding an E-Mail message from a " & _
"restricted employee, do you wish to " & _
"continue?", vbYesNo, "Rule Execution") = vbYes)

If blnExecute = True Then

'Eventually want some code to capture that
'the end-user chose to send the E-Mail
'message.

ElseIf blnExecute = False Then

Cancel = True 'this will cancel the send

End If

End If

Thanks for your help as always.

axla

code for automatic select value from ms-excel column

muhammadataulhaqsultani22-Jul-09 17:57

muhammadataulhaqsultani

22-Jul-09 17:57

Hi, I just need code that I have 4 column A B C D in Ms-Excel

In VB Form I had list first 2 columns value in Combo Box

& 3rd column is also combo Box containing “Auto & Manual”

4th column is sum of column A & B

In VB form there is Text Box in which the Answer or the Sum “column D” must be shown

But I don’nt know what code use for Text box or Auto Manual combo box to display column D in Text box

Thanks & regards:

Muhammad Ata-ul-haq Sultani

Re: code for automatic select value from ms-excel column

Sumit Prakash Sharma22-Jul-09 21:26

Sumit Prakash Sharma

22-Jul-09 21:26

Plz post your problem in detail, so that i could solve it. It is not too hard to read data or record from excel sheet.

Re: code for automatic select value from ms-excel column

muhammadataulhaqsultani23-Jul-09 16:08

muhammadataulhaqsultani

23-Jul-09 16:08

In short when I select Auto from combo box I need the values(which are in column D in excel) in text Box

Multi-D Array comparisons

Member 437454222-Jul-09 15:18

Member 4374542

22-Jul-09 15:18

hi, im new-ish to vb

im currently pseudocoding a program for sorting some data. the data is pulled from file or database, then compared against some fields in another file or db, then put into an array. the initial data has 5 fields, the second has 8, and the result has 2 fields. at the moment its 400+ entries with 40-60 groups with 4-8 comparisons for each

what i am endlessly confused about is if a 5D array "appears" the same as a db table with 5 columns or if it more closely resembles a black hole (so i can visualise it a bit easier) and whether it would be easier to code 5 x 2D arrays for the data and another 8 x 2D for the tests
oh, and which method is more efficient

-N

note: i have completed the file>array bit and can compare two arrays

Re: Multi-D Array comparisons

Luc Pattyn22-Jul-09 15:47

Luc Pattyn

22-Jul-09 15:47

IMO a database table is a one-dimensional array holding rows; each row holds fields of different types, something an array isn't capable of in most languages.
In C#, C/C++, or VB.NET a row could be represented by a class or struct, where each field corresponds to one field of the datatable row.

Do not use multi-dimensional arrays if you don't really need them, and don't use parallel one-dimensional arrays either: use more structured data, as in an array of structs/classes.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.

Re: Multi-D Array comparisons

Member 437454222-Jul-09 16:09

Member 4374542

22-Jul-09 16:09

thats very useful
thanks for the fast reply

Re: Multi-D Array comparisons

Luc Pattyn22-Jul-09 16:10

Luc Pattyn

22-Jul-09 16:10

you're welcome.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.

How do I modify a class so you can convert a String to it?

i_kant_spel22-Jul-09 9:48

i_kant_spel

22-Jul-09 9:48

This is a stub version of the actual problem.

Here are two files. Form1.vb, which looks like this:

Public Class Form1

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

        Dim myIKGrid As New IKGrid
        myIKGrid.Columns(0).Caption = "English"
        myIKGrid.Columns(0) = "Zero"

    End Sub
End Class

You cannot modify Form1 for any reason whatsoever.

The other file is IKGrid.vb. It looks like this:

Public Class IKGrid

    Public Property Columns(ByVal s As Short) As IKColumn
        Get
            Return Nothing
        End Get
        Set(ByVal value As IKColumn)

        End Set
    End Property

End Class

Public Class IKColumn

    Public Property Caption() As String
        Get
            Return ""
        End Get
        Set(ByVal value As String)

        End Set
    End Property

End Class

You can modify IKGrid any way you please.

Anyway, this code results in a compile error. The line:

myIKGrid.Columns(0) = "Zero"

causes

Value of type 'String' cannot be converted to 'IKColumn'

So, how can you modify the IKGrid file so that the String CAN be converted to an IKColumn? The project doesn't need to do anything useful, it just needs to be able to compile without errors.

Re: How do I modify a class so you can convert a String to it?

Luc Pattyn22-Jul-09 10:36

Luc Pattyn

22-Jul-09 10:36

i_kant_spel wrote:
The project doesn't need to do anything useful

Interesting prospect.

From myIKGrid.Columns(0) = "Zero" it would seem IKGrid.Columns[] is a string array, however you can't get myIKGrid.Columns(0).Caption = "English" right since a string doesn't have a Caption property.

Hence, IKGrid.Columns must be a type that has a Caption property, and has an override for the = operator.
The remainder is left as your homework.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.

Re: How do I modify a class so you can convert a String to it?

Gideon Engelberth22-Jul-09 12:36

Gideon Engelberth

22-Jul-09 12:36

Override for the = operator? Only in C++ where nothing means anything because everything can be overriden. There are not overrides for assignment in .NET (or VB6 for that matter), though with default properties, it could sometimes look that way.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.