Including a class as a member of another class

**pritiphadke@gmail.com** · Nov 21 '05, 09:57 AM

Re: Including a class as a member of another class

Try

Namespace DataTypesVB.Enu merations
Public Class DefaultValues
Public Name As String
Public Lenders() As New clsLender
End Class
End Namespace

**Robby** · Nov 21 '05, 09:57 AM

Re: Including a class as a member of another class

You should not give your variables the same name as the class name. It is
confusing.

This statement ...

Dim DefaultValues As New DataTypesVB.Enu merations.Defau ltValues()

creates an empty array of DataTypesVB.Enu merations.Defau ltValues. So that
when these lines are executed ...

With DefaultValues
.Name = some value
End With

you get the "Object reference not set to an instance of an object" error.
Remove the opening and closing brackets at the end of the declaration and
things should work better.

More importantly, do not give your variable names the same name as the class
name. This is extremely poor programming practice. It makes it makes it
difficult to see if you are invoking an instance or shared property or
procedure. While it does not count in this small example when you get to
larger programs you will have headaches.

Robby

"Jeff Cobelli" <jcobelli@theim pactgroup.com> wrote in message
news:OunTYP38EH A.3700@tk2msftn gp13.phx.gbl...[color=blue]
>I am trying to include two classes as members of another class in a
>webservice. The definitions look basically like this:
>
> Public Class clsLender
> Public ID As String
> Public Name As String
> End Class
> ----------------------------------------------------------------------------------------
> Namespace DataTypesVB.Enu merations
> Public Class DefaultValues
> Public Name As String
> Public Lenders() As clsLender
> End Class
> End Namespace
>
> Then the code looks like this:
>
> <WebMethod()> Public Function GetDefaultValue s( ByVal some value As Guid)
> As DataTypesVB.Enu merations.Defau ltValues
> Dim i As Integer
> Dim DefaultValues As New DataTypesVB.Enu merations.Defau ltValues()
> With DefaultValues
> .Name = some value
> End With
>
> For i = 0 To some number
> With DefaultValues
> ReDim Preserve .Lenders(i)
> .Lenders(i).ID = some value
> .Lenders(i).Nam e = some value
> End With
> Next i
> Return DefaultValues
> End Function
>
> When I run this web service (quite a bit of code has been cut for
> readability) I get the following error:
>
> <faultstring>Se rver was unable to process request. --> Object reference
> not set to an instance of an object.</faultstring>
>
> Please help me understand where my failure is and how I can fix it.
> Thanks in advance!
>
> - Jeff
>[/color]

**Jeff Cobelli** · Nov 21 '05, 09:58 AM

Re: Including a class as a member of another class

Hi Robby - thanks for your response. I took your advice and removed the
opening and closing parenthesis at the end of the variable declaration (this
also required me to remove the "New" keyword). Anyway, the same error still
gets returned. The web service is not failing on the line where I assign a
value to DefaultValues.N ame. The problem is occurring somewhere in the
following code:

For i = 0 To some number
With DefaultValues
ReDim Preserve .Lenders(i)
.Lenders(i).ID = some value
.Lenders(i).Nam e = some value
End With
Next i

I am assuming it has something to do with redimensioning the Lenders class.
I know it is here because if I comment this section out the web service runs
fine and returns the expected result. Do you have any other ideas for
resolving this problem?

Thanks also for your suggestions regarding naming conventions. I'll
definitely put your advice into practice.

Thanks in advance,

- Jeff

"Robby" <edmund@not.my. email.com> wrote in message
news:uxNF%23838 EHA.2572@tk2msf tngp13.phx.gbl. ..[color=blue]
>
> You should not give your variables the same name as the class name. It is
> confusing.
>
> This statement ...
>
> Dim DefaultValues As New DataTypesVB.Enu merations.Defau ltValues()
>
> creates an empty array of DataTypesVB.Enu merations.Defau ltValues. So that
> when these lines are executed ...
>
> With DefaultValues
> .Name = some value
> End With
>
> you get the "Object reference not set to an instance of an object" error.
> Remove the opening and closing brackets at the end of the declaration and
> things should work better.
>
> More importantly, do not give your variable names the same name as the
> class name. This is extremely poor programming practice. It makes it
> makes it difficult to see if you are invoking an instance or shared
> property or procedure. While it does not count in this small example when
> you get to larger programs you will have headaches.
>
> Robby
>
>
>
> "Jeff Cobelli" <jcobelli@theim pactgroup.com> wrote in message
> news:OunTYP38EH A.3700@tk2msftn gp13.phx.gbl...[color=green]
>>I am trying to include two classes as members of another class in a
>>webservice. The definitions look basically like this:
>>
>> Public Class clsLender
>> Public ID As String
>> Public Name As String
>> End Class
>> ----------------------------------------------------------------------------------------
>> Namespace DataTypesVB.Enu merations
>> Public Class DefaultValues
>> Public Name As String
>> Public Lenders() As clsLender
>> End Class
>> End Namespace
>>
>> Then the code looks like this:
>>
>> <WebMethod()> Public Function GetDefaultValue s( ByVal some value As Guid)
>> As DataTypesVB.Enu merations.Defau ltValues
>> Dim i As Integer
>> Dim DefaultValues As New DataTypesVB.Enu merations.Defau ltValues()
>> With DefaultValues
>> .Name = some value
>> End With
>>
>> For i = 0 To some number
>> With DefaultValues
>> ReDim Preserve .Lenders(i)
>> .Lenders(i).ID = some value
>> .Lenders(i).Nam e = some value
>> End With
>> Next i
>> Return DefaultValues
>> End Function
>>
>> When I run this web service (quite a bit of code has been cut for
>> readability) I get the following error:
>>
>> <faultstring>Se rver was unable to process request. --> Object reference
>> not set to an instance of an object.</faultstring>
>>
>> Please help me understand where my failure is and how I can fix it.
>> Thanks in advance!
>>
>> - Jeff
>>[/color]
>
>[/color]

**Robby** · Nov 21 '05, 09:58 AM

Re: Including a class as a member of another class

So sorry, the New keyword line is ok. I was a little confused by the
variable name with the class name. So the real problem is that ...

ReDim Preserve .Lenders(i)

extends the DefaultValues.L enders array with one more entry BUT it does not
initalize that entry. Therefore, you need to initalize the entry before you
invoke its instance properties or procedures.
[color=blue]
> With DefaultValues
> ReDim Preserve .Lenders(i)[/color]
* .Lenders(i) = New clsLender()[color=blue]
> .Lenders(i).ID = some value
> .Lenders(i).Nam e = some value
> End With[/color]

Robby

"Jeff Cobelli" <jcobelli@theim pactgroup.com> wrote in message
news:%23$8mxZ58 EHA.3840@tk2msf tngp13.phx.gbl. ..[color=blue]
> Hi Robby - thanks for your response. I took your advice and removed the
> opening and closing parenthesis at the end of the variable declaration
> (this also required me to remove the "New" keyword). Anyway, the same
> error still gets returned. The web service is not failing on the line
> where I assign a value to DefaultValues.N ame. The problem is occurring
> somewhere in the following code:
>
> For i = 0 To some number
> With DefaultValues
> ReDim Preserve .Lenders(i)
> .Lenders(i).ID = some value
> .Lenders(i).Nam e = some value
> End With
> Next i
>
> I am assuming it has something to do with redimensioning the Lenders
> class. I know it is here because if I comment this section out the web
> service runs fine and returns the expected result. Do you have any other
> ideas for resolving this problem?
>
> Thanks also for your suggestions regarding naming conventions. I'll
> definitely put your advice into practice.
>
> Thanks in advance,
>
> - Jeff
>
> "Robby" <edmund@not.my. email.com> wrote in message
> news:uxNF%23838 EHA.2572@tk2msf tngp13.phx.gbl. ..[color=green]
>>
>> You should not give your variables the same name as the class name. It
>> is confusing.
>>
>> This statement ...
>>
>> Dim DefaultValues As New DataTypesVB.Enu merations.Defau ltValues()
>>
>> creates an empty array of DataTypesVB.Enu merations.Defau ltValues. So that
>> when these lines are executed ...
>>
>> With DefaultValues
>> .Name = some value
>> End With
>>
>> you get the "Object reference not set to an instance of an object" error.
>> Remove the opening and closing brackets at the end of the declaration and
>> things should work better.
>>
>> More importantly, do not give your variable names the same name as the
>> class name. This is extremely poor programming practice. It makes it
>> makes it difficult to see if you are invoking an instance or shared
>> property or procedure. While it does not count in this small example
>> when you get to larger programs you will have headaches.
>>
>> Robby
>>
>>
>>
>> "Jeff Cobelli" <jcobelli@theim pactgroup.com> wrote in message
>> news:OunTYP38EH A.3700@tk2msftn gp13.phx.gbl...[color=darkred]
>>>I am trying to include two classes as members of another class in a
>>>webservice . The definitions look basically like this:
>>>
>>> Public Class clsLender
>>> Public ID As String
>>> Public Name As String
>>> End Class
>>> ----------------------------------------------------------------------------------------
>>> Namespace DataTypesVB.Enu merations
>>> Public Class DefaultValues
>>> Public Name As String
>>> Public Lenders() As clsLender
>>> End Class
>>> End Namespace
>>>
>>> Then the code looks like this:
>>>
>>> <WebMethod()> Public Function GetDefaultValue s( ByVal some value As
>>> Guid) As DataTypesVB.Enu merations.Defau ltValues
>>> Dim i As Integer
>>> Dim DefaultValues As New DataTypesVB.Enu merations.Defau ltValues()
>>> With DefaultValues
>>> .Name = some value
>>> End With
>>>
>>> For i = 0 To some number
>>> With DefaultValues
>>> ReDim Preserve .Lenders(i)
>>> .Lenders(i).ID = some value
>>> .Lenders(i).Nam e = some value
>>> End With
>>> Next i
>>> Return DefaultValues
>>> End Function
>>>
>>> When I run this web service (quite a bit of code has been cut for
>>> readability) I get the following error:
>>>
>>> <faultstring>Se rver was unable to process request. --> Object reference
>>> not set to an instance of an object.</faultstring>
>>>
>>> Please help me understand where my failure is and how I can fix it.
>>> Thanks in advance!
>>>
>>> - Jeff
>>>[/color]
>>
>>[/color]
>
>[/color]

**Jeff Cobelli** · Nov 21 '05, 09:59 AM

Re: Including a class as a member of another class

You are the best, thank you!

- Jeff

"Robby" <edmund@not.my. email.com> wrote in message
news:uGx%23$g78 EHA.3596@TK2MSF TNGP12.phx.gbl. ..[color=blue]
>
> So sorry, the New keyword line is ok. I was a little confused by the
> variable name with the class name. So the real problem is that ...
>
> ReDim Preserve .Lenders(i)
>
> extends the DefaultValues.L enders array with one more entry BUT it does
> not initalize that entry. Therefore, you need to initalize the entry
> before you invoke its instance properties or procedures.
>[color=green]
>> With DefaultValues
>> ReDim Preserve .Lenders(i)[/color]
> * .Lenders(i) = New clsLender()[color=green]
>> .Lenders(i).ID = some value
>> .Lenders(i).Nam e = some value
>> End With[/color]
>
> Robby
>
>
> "Jeff Cobelli" <jcobelli@theim pactgroup.com> wrote in message
> news:%23$8mxZ58 EHA.3840@tk2msf tngp13.phx.gbl. ..[color=green]
>> Hi Robby - thanks for your response. I took your advice and removed the
>> opening and closing parenthesis at the end of the variable declaration
>> (this also required me to remove the "New" keyword). Anyway, the same
>> error still gets returned. The web service is not failing on the line
>> where I assign a value to DefaultValues.N ame. The problem is occurring
>> somewhere in the following code:
>>
>> For i = 0 To some number
>> With DefaultValues
>> ReDim Preserve .Lenders(i)
>> .Lenders(i).ID = some value
>> .Lenders(i).Nam e = some value
>> End With
>> Next i
>>
>> I am assuming it has something to do with redimensioning the Lenders
>> class. I know it is here because if I comment this section out the web
>> service runs fine and returns the expected result. Do you have any other
>> ideas for resolving this problem?
>>
>> Thanks also for your suggestions regarding naming conventions. I'll
>> definitely put your advice into practice.
>>
>> Thanks in advance,
>>
>> - Jeff
>>
>> "Robby" <edmund@not.my. email.com> wrote in message
>> news:uxNF%23838 EHA.2572@tk2msf tngp13.phx.gbl. ..[color=darkred]
>>>
>>> You should not give your variables the same name as the class name. It
>>> is confusing.
>>>
>>> This statement ...
>>>
>>> Dim DefaultValues As New DataTypesVB.Enu merations.Defau ltValues()
>>>
>>> creates an empty array of DataTypesVB.Enu merations.Defau ltValues. So
>>> that when these lines are executed ...
>>>
>>> With DefaultValues
>>> .Name = some value
>>> End With
>>>
>>> you get the "Object reference not set to an instance of an object"
>>> error. Remove the opening and closing brackets at the end of the
>>> declaration and things should work better.
>>>
>>> More importantly, do not give your variable names the same name as the
>>> class name. This is extremely poor programming practice. It makes it
>>> makes it difficult to see if you are invoking an instance or shared
>>> property or procedure. While it does not count in this small example
>>> when you get to larger programs you will have headaches.
>>>
>>> Robby
>>>
>>>
>>>
>>> "Jeff Cobelli" <jcobelli@theim pactgroup.com> wrote in message
>>> news:OunTYP38EH A.3700@tk2msftn gp13.phx.gbl...
>>>>I am trying to include two classes as members of another class in a
>>>>webservic e. The definitions look basically like this:
>>>>
>>>> Public Class clsLender
>>>> Public ID As String
>>>> Public Name As String
>>>> End Class
>>>> ----------------------------------------------------------------------------------------
>>>> Namespace DataTypesVB.Enu merations
>>>> Public Class DefaultValues
>>>> Public Name As String
>>>> Public Lenders() As clsLender
>>>> End Class
>>>> End Namespace
>>>>
>>>> Then the code looks like this:
>>>>
>>>> <WebMethod()> Public Function GetDefaultValue s( ByVal some value As
>>>> Guid) As DataTypesVB.Enu merations.Defau ltValues
>>>> Dim i As Integer
>>>> Dim DefaultValues As New DataTypesVB.Enu merations.Defau ltValues()
>>>> With DefaultValues
>>>> .Name = some value
>>>> End With
>>>>
>>>> For i = 0 To some number
>>>> With DefaultValues
>>>> ReDim Preserve .Lenders(i)
>>>> .Lenders(i).ID = some value
>>>> .Lenders(i).Nam e = some value
>>>> End With
>>>> Next i
>>>> Return DefaultValues
>>>> End Function
>>>>
>>>> When I run this web service (quite a bit of code has been cut for
>>>> readability) I get the following error:
>>>>
>>>> <faultstring>Se rver was unable to process request. --> Object reference
>>>> not set to an instance of an object.</faultstring>
>>>>
>>>> Please help me understand where my failure is and how I can fix it.
>>>> Thanks in advance!
>>>>
>>>> - Jeff
>>>>
>>>
>>>[/color]
>>
>>[/color]
>
>[/color]

Including a class as a member of another class

Including a class as a member of another class

Comment

Comment

Comment

Comment

Comment