Using reflection to get instance name

[=?Utf-8?B?SmFzb24gUmV5bm9sZHM=?=]

(using .net 2.0)

Say you have a class structure like this:

class Address
....
end class

class Person
FirstName
LastName
MailingAddress as Address
BillingAddress as Address
end class

I'm using reflection to pull out the values at runtime, but I'm having
trouble when I dive into an address. When I'm traversing the object I know
when the type is address and I can get and set values on that instance, but I
can't figure a way to know if I'm looking at the mailing address or the
billing address. Is there a way to get the instance name of an object at
runtime? I've thought about setting a name property in the object, but
that's a bit of a hack and makes things much less reusable. Thanks in
advance.

[=?Utf-8?B?S2VycnkgTW9vcm1hbg==?=]

RE: Using reflection to get instance name

Jason,

Just out of curiosity, what kind of problem are you trying to solve where
you would need to use reflection in what looks like a typical business
application?

Kerry Moorman


"Jason Reynolds" wrote:

(using .net 2.0)
>
Say you have a class structure like this:
>
class Address
...
end class
>
class Person
FirstName
LastName
MailingAddress as Address
BillingAddress as Address
end class
>
I'm using reflection to pull out the values at runtime, but I'm having
trouble when I dive into an address. When I'm traversing the object I know
when the type is address and I can get and set values on that instance, but I
can't figure a way to know if I'm looking at the mailing address or the
billing address. Is there a way to get the instance name of an object at
runtime? I've thought about setting a name property in the object, but
that's a bit of a hack and makes things much less reusable. Thanks in
advance.

[=?Utf-8?B?SmFzb24gUmV5bm9sZHM=?=]

RE: Using reflection to get instance name

Thanks for responding so quickly, Kerry.

I'm building a library to do two-way databinding of business objects and web
forms. I'm not going the full scaffolding route, instead simply matching
property names with control names. I want it to be generic so I can simply
pass a business object, say Person, and the page control and have binding
done going in and coming out.



"Kerry Moorman" wrote:

Jason,
>
Just out of curiosity, what kind of problem are you trying to solve where
you would need to use reflection in what looks like a typical business
application?
>
Kerry Moorman
>
>
"Jason Reynolds" wrote:
>

(using .net 2.0)

Say you have a class structure like this:

class Address
...
end class

class Person
FirstName
LastName
MailingAddress as Address
BillingAddress as Address
end class

I'm using reflection to pull out the values at runtime, but I'm having
trouble when I dive into an address. When I'm traversing the object I know
when the type is address and I can get and set values on that instance, but I
can't figure a way to know if I'm looking at the mailing address or the
billing address. Is there a way to get the instance name of an object at
runtime? I've thought about setting a name property in the object, but
that's a bit of a hack and makes things much less reusable. Thanks in
advance.

[Jay B. Harlow [MVP - Outlook]]

Re: Using reflection to get instance name

Jason,

Is there a way to get the instance name of an object at
runtime?

Short answer NO!

Long answer:

Instances are not named in .NET per se, variables & fields are named...

What name would you expect when you do:

Dim jason As New Person
Dim nowhere As New Address
jason.MailingAd dress = nowhere
jason.BillingAd dress = nowhere

Remember Address is a reference object, so nowhere, jason.MailingAd dress and
jason.BillingAd dress all refer to the same instance.

I've thought about setting a name property in the object, but
that's a bit of a hack and makes things much less reusable.

If knowing the difference between a Mailing address & a Billing address is
important I would either define an AddressType property (an Enum) that had
the address types on it.

Enum AddressType
Billing
Mailing
End Enum

class Address
...

Type As AddressType

end class

Or I would make Address abstract (MustInherit) and have MailingAddress &
BillingAddress inherit from Address.

class MustInherit Address
...
end class

class MailingAddress
Inherits Address
...
end class

class BillingAddress
Inherits Address
...
end class

class Person
FirstName
LastName
MailingAddress as MailingAddress
BillingAddress as BillingAddress
end class

I would use the second if I had "significan t" polymorphic behavior between
mailing addresses & billing addresses

--
Hope this helps
Jay B. Harlow [MVP - Outlook]
..NET Application Architect, Enthusiast, & Evangelist
T.S. Bradley - http://www.tsbradley.net


"Jason Reynolds" <JasonReynolds@ discussions.mic rosoft.comwrote in message
news:3E6CB8E1-B9F2-47F9-82AA-8AE811A1CB8C@mi crosoft.com...

(using .net 2.0)
>
Say you have a class structure like this:
>
class Address
...
end class
>
class Person
FirstName
LastName
MailingAddress as Address
BillingAddress as Address
end class
>
I'm using reflection to pull out the values at runtime, but I'm having
trouble when I dive into an address. When I'm traversing the object I
know
when the type is address and I can get and set values on that instance,
but I
can't figure a way to know if I'm looking at the mailing address or the
billing address. Is there a way to get the instance name of an object at
runtime? I've thought about setting a name property in the object, but
that's a bit of a hack and makes things much less reusable. Thanks in
advance.

[=?Utf-8?B?SmFzb24gUmV5bm9sZHM=?=]

Re: Using reflection to get instance name

Thanks for your reply, Jay. Adding an enum or abstracting the class isn't
quite what I'm looking for. Your explanation of instances and reference
objects is very helpful and crystallized the concept in my mind. Because of
this I think I'll try another approach. Thanks a bunch for your time.

"Jay B. Harlow [MVP - Outlook]" wrote:

Jason,

Is there a way to get the instance name of an object at
runtime?

Short answer NO!
>
Long answer:
>
Instances are not named in .NET per se, variables & fields are named...
>
What name would you expect when you do:
>
Dim jason As New Person
Dim nowhere As New Address
jason.MailingAd dress = nowhere
jason.BillingAd dress = nowhere
>
Remember Address is a reference object, so nowhere, jason.MailingAd dress and
jason.BillingAd dress all refer to the same instance.
>

I've thought about setting a name property in the object, but
that's a bit of a hack and makes things much less reusable.

If knowing the difference between a Mailing address & a Billing address is
important I would either define an AddressType property (an Enum) that had
the address types on it.
>
Enum AddressType
Billing
Mailing
End Enum
>

class Address
...

Type As AddressType

end class

>
>
Or I would make Address abstract (MustInherit) and have MailingAddress &
BillingAddress inherit from Address.
>

class MustInherit Address
...
end class

>
class MailingAddress
Inherits Address
...
end class
>
class BillingAddress
Inherits Address
...
end class
>

class Person
FirstName
LastName
MailingAddress as MailingAddress
BillingAddress as BillingAddress
end class

>
I would use the second if I had "significan t" polymorphic behavior between
mailing addresses & billing addresses
>
--
Hope this helps
Jay B. Harlow [MVP - Outlook]
.NET Application Architect, Enthusiast, & Evangelist
T.S. Bradley - http://www.tsbradley.net
>
>
"Jason Reynolds" <JasonReynolds@ discussions.mic rosoft.comwrote in message
news:3E6CB8E1-B9F2-47F9-82AA-8AE811A1CB8C@mi crosoft.com...

(using .net 2.0)

Say you have a class structure like this:

class Address
...
end class

class Person
FirstName
LastName
MailingAddress as Address
BillingAddress as Address
end class

I'm using reflection to pull out the values at runtime, but I'm having
trouble when I dive into an address. When I'm traversing the object I
know
when the type is address and I can get and set values on that instance,
but I
can't figure a way to know if I'm looking at the mailing address or the
billing address. Is there a way to get the instance name of an object at
runtime? I've thought about setting a name property in the object, but
that's a bit of a hack and makes things much less reusable. Thanks in
advance.

>