IStateManager in a class object

Brad

I am creating a class (not a control) which implements IStateManager. I've
created the class and all of the implementations (LoadView, SaveViewState,
etc...). My Question is: How do I instantiate this class in a page and
then re-instantiate it on post back such that I don't lose it's viewstate?
If the page always uses x = new myclass to instantiate, the myclass
constructor is always going to reinitialize its statebag.

Nov 19 '05 #1

Subscribe Reply

1279

Brock Allen

This approach is typically done when a control (or the page) needs to use
a helper object to track the viewstate. So the usage model is for the control
to instantiate an instance of the helper object and then override all of
the IStateManager APIs and call into the helper object for each one (so override
LoadViewState and the call into the helper's LoadViewState, etc...). This
is how the helper object gets 'hooked into' the page model. I hope that just
made sense :)

-Brock
DevelopMentor
http://staff.develop.com/ballen

I am creating a class (not a control) which implements IStateManager.
I've created the class and all of the implementations (LoadView,
SaveViewState, etc...). My Question is: How do I instantiate this
class in a page and then re-instantiate it on post back such that I
don't lose it's viewstate? If the page always uses x = new myclass to
instantiate, the myclass constructor is always going to reinitialize
its statebag.

Nov 19 '05 #2

Brad

Thanks for the reply....but you lost me there. If I'm using this in a page
I understand about overriding the pages LoadViewState, SaveViewState.. .and
calling the helper class LoadViewState, etc... The paradox I'm lost on is
how the instance of the helper is saved and reinstantiated such that the
value in it's statebag persist. The page needs to instantiate the helper
somewhere. And if the helper has a constructor which instantiates the
statebag, the statebag (and thus the viewstate) is going to be empty.

"Brock Allen" <ba****@NOSPAMd evelop.com> wrote in message
news:b8******** *************** ***@msnews.micr osoft.com...
This approach is typically done when a control (or the page) needs to use
a helper object to track the viewstate. So the usage model is for the
control
to instantiate an instance of the helper object and then override all of
the IStateManager APIs and call into the helper object for each one (so
override
LoadViewState and the call into the helper's LoadViewState, etc...). This
is how the helper object gets 'hooked into' the page model. I hope that just
made sense :)

-Brock
DevelopMentor
http://staff.develop.com/ballen

I am creating a class (not a control) which implements IStateManager.
I've created the class and all of the implementations (LoadView,
SaveViewState, etc...). My Question is: How do I instantiate this
class in a page and then re-instantiate it on post back such that I
don't lose it's viewstate? If the page always uses x = new myclass to
instantiate, the myclass constructor is always going to reinitialize
its statebag.

Nov 19 '05 #3

Brock Allen

Right, so you'll create the helper and it will be empty until LoadViewState
is called. That's why it's important to forward the overrides to the helper.
So, yes, ViewState won't be loaded until the Page base class calls the LoadViewState
virtual.

-Brock
DevelopMentor
http://staff.develop.com/ballen

Thanks for the reply....but you lost me there. If I'm using this in a
page I understand about overriding the pages LoadViewState,
SaveViewState.. .and calling the helper class LoadViewState, etc...
The paradox I'm lost on is how the instance of the helper is saved and
reinstantiated such that the value in it's statebag persist. The page
needs to instantiate the helper somewhere. And if the helper has a
constructor which instantiates the statebag, the statebag (and thus
the viewstate) is going to be empty.

"Brock Allen" <ba****@NOSPAMd evelop.com> wrote in message
news:b8******** *************** ***@msnews.micr osoft.com...
This approach is typically done when a control (or the page) needs to
use
a helper object to track the viewstate. So the usage model is for the
control
to instantiate an instance of the helper object and then override all
of
the IStateManager APIs and call into the helper object for each one
(so
override
LoadViewState and the call into the helper's LoadViewState, etc...).
This
is how the helper object gets 'hooked into' the page model. I hope
that just
made sense :)
-Brock
DevelopMentor
http://staff.develop.com/ballen
I am creating a class (not a control) which implements IStateManager.
I've created the class and all of the implementations (LoadView,
SaveViewState, etc...). My Question is: How do I instantiate this
class in a page and then re-instantiate it on post back such that I
don't lose it's viewstate? If the page always uses x = new myclass
to instantiate, the myclass constructor is always going to
reinitialize its statebag.

Nov 19 '05 #4

Steven Cheng[MSFT]

Hi Brad,

My understanding on your question is that you want your custom component
class be able to automatically be able to utilize the asp.net page's state
management, (e.g. persist and load states into/from viewstate).
If so, I'm afraid a normal class can not automatically hook into these
process/ events model since the ASP.NET page doesn't know that it need to
call your custom class's certain state mangement api. To achieve this, we
need to override page class's LoadViewState/SaveViewState funciton or hook
into the Init ,Load, event so as to construct and populate your custom
class's instance on the page. However I don't think this is possible for a
common component class.

So the option left to us is just derive our class from the
System.Web.UI.C ontrol, and when used on page, it is added into the asp.net
page's control collection. So that ASP.NET page will know that it need to
call your object(control) 's state management methods at the proper time.
Actually we can find some realworld examples like the DataSource controls
in asp.net 2.0, though they're only utility components which haven't UI
related task, they're still designed as Control since they need to hook
into the asp.net page's runtime event model and state management steps.

Thanks,

Steven Cheng
Microsoft Online Support

Get Secure! www.microsoft.com/security
(This posting is provided "AS IS", with no warranties, and confers no
rights.)

--------------------
| Message-ID: <b8************ **************@ msnews.microsof t.com>
| From: Brock Allen <ba****@NOSPAMd evelop.com>
| Subject: Re: IStateManager in a class object
| References: <Op************ **@TK2MSFTNGP09 .phx.gbl>
| MIME-Version: 1.0
| Content-Transfer-Encoding: 8bit
| Content-Type: text/plain; charset=iso-8859-1; format=flowed
| X-Newsreader: JetBrains Omea Reader 671.6
| Newsgroups: microsoft.publi c.dotnet.framew ork.aspnet
| Date: Thu, 29 Sep 2005 14:55:26 -0700
| NNTP-Posting-Host: host81-153-126-137.range81-153.btcentralpl us.com
81.153.126.137
| Lines: 1
| Path: TK2MSFTNGXA01.p hx.gbl!TK2MSFTN GP08.phx.gbl!tk 2msftngp13.phx. gbl
| Xref: TK2MSFTNGXA01.p hx.gbl
microsoft.publi c.dotnet.framew ork.aspnet:1281 15
| X-Tomcat-NG: microsoft.publi c.dotnet.framew ork.aspnet
|
| Right, so you'll create the helper and it will be empty until
LoadViewState
| is called. That's why it's important to forward the overrides to the
helper.
| So, yes, ViewState won't be loaded until the Page base class calls the
LoadViewState
| virtual.
|
| -Brock
| DevelopMentor
| http://staff.develop.com/ballen
|
| > Thanks for the reply....but you lost me there. If I'm using this in a
| > page I understand about overriding the pages LoadViewState,
| > SaveViewState.. .and calling the helper class LoadViewState, etc...
| > The paradox I'm lost on is how the instance of the helper is saved and
| > reinstantiated such that the value in it's statebag persist. The page
| > needs to instantiate the helper somewhere. And if the helper has a
| > constructor which instantiates the statebag, the statebag (and thus
| > the viewstate) is going to be empty.
| >
| > "Brock Allen" <ba****@NOSPAMd evelop.com> wrote in message
| > news:b8******** *************** ***@msnews.micr osoft.com...
| > This approach is typically done when a control (or the page) needs to
| > use
| > a helper object to track the viewstate. So the usage model is for the
| > control
| > to instantiate an instance of the helper object and then override all
| > of
| > the IStateManager APIs and call into the helper object for each one
| > (so
| > override
| > LoadViewState and the call into the helper's LoadViewState, etc...).
| > This
| > is how the helper object gets 'hooked into' the page model. I hope
| > that just
| > made sense :)
| > -Brock
| > DevelopMentor
| > http://staff.develop.com/ballen
| >> I am creating a class (not a control) which implements IStateManager.
| >> I've created the class and all of the implementations (LoadView,
| >> SaveViewState, etc...). My Question is: How do I instantiate this
| >> class in a page and then re-instantiate it on post back such that I
| >> don't lose it's viewstate? If the page always uses x = new myclass
| >> to instantiate, the myclass constructor is always going to
| >> reinitialize its statebag.
| >>

|
|

Nov 19 '05 #5

Brock Allen

Brad, send me an email and I can send you a sample implementation.

-Brock
DevelopMentor
http://staff.develop.com/ballen

Right, so you'll create the helper and it will be empty until
LoadViewState is called. That's why it's important to forward the
overrides to the helper. So, yes, ViewState won't be loaded until the
Page base class calls the LoadViewState virtual.

-Brock
DevelopMentor
http://staff.develop.com/ballen
Thanks for the reply....but you lost me there. If I'm using this in
a
page I understand about overriding the pages LoadViewState,
SaveViewState.. .and calling the helper class LoadViewState, etc...
The paradox I'm lost on is how the instance of the helper is saved
and
reinstantiated such that the value in it's statebag persist. The
page
needs to instantiate the helper somewhere. And if the helper has a
constructor which instantiates the statebag, the statebag (and thus
the viewstate) is going to be empty.
"Brock Allen" <ba****@NOSPAMd evelop.com> wrote in message
news:b8******** *************** ***@msnews.micr osoft.com...
This approach is typically done when a control (or the page) needs to
use
a helper object to track the viewstate. So the usage model is for the
control
to instantiate an instance of the helper object and then override all
of
the IStateManager APIs and call into the helper object for each one
(so
override
LoadViewState and the call into the helper's LoadViewState, etc...).
This
is how the helper object gets 'hooked into' the page model. I hope
that just
made sense :)
-Brock
DevelopMentor
http://staff.develop.com/ballen
I am creating a class (not a control) which implements
IStateManager. I've created the class and all of the implementations
(LoadView, SaveViewState, etc...). My Question is: How do I
instantiate this class in a page and then re-instantiate it on post
back such that I don't lose it's viewstate? If the page always uses
x = new myclass to instantiate, the myclass constructor is always
going to reinitialize its statebag.

Nov 19 '05 #6

Steven Cheng[MSFT]

Hi Brad,

How are you doing on this post. Does the suggestions in my last reply helps
a little? If there're anything else we can help, please feel free to post
here.

Thanks,

Steven Cheng
Microsoft Online Support

Get Secure! www.microsoft.com/security
--------------------
| X-Tomcat-ID: 54974071
| References: <Op************ **@TK2MSFTNGP09 .phx.gbl>
<b8************ **************@ msnews.microsof t.com>
| MIME-Version: 1.0
| Content-Type: text/plain
| Content-Transfer-Encoding: 7bit
| From: st*****@online. microsoft.com (Steven Cheng[MSFT])
| Organization: Microsoft
| Date: Fri, 30 Sep 2005 03:38:33 GMT
| Subject: Re: IStateManager in a class object
| X-Tomcat-NG: microsoft.publi c.dotnet.framew ork.aspnet
| Message-ID: <UL************ **@TK2MSFTNGXA0 1.phx.gbl>
| Newsgroups: microsoft.publi c.dotnet.framew ork.aspnet
| Lines: 111
| Path: TK2MSFTNGXA01.p hx.gbl
| Xref: TK2MSFTNGXA01.p hx.gbl
microsoft.publi c.dotnet.framew ork.aspnet:1281 62
| NNTP-Posting-Host: tomcatimport2.p hx.gbl 10.201.218.182
|
| Hi Brad,
|
| My understanding on your question is that you want your custom component
| class be able to automatically be able to utilize the asp.net page's
state
| management, (e.g. persist and load states into/from viewstate).
| If so, I'm afraid a normal class can not automatically hook into these
| process/ events model since the ASP.NET page doesn't know that it need to
| call your custom class's certain state mangement api. To achieve this, we
| need to override page class's LoadViewState/SaveViewState funciton or
hook
| into the Init ,Load, event so as to construct and populate your custom
| class's instance on the page. However I don't think this is possible for
a
| common component class.
|
| So the option left to us is just derive our class from the
| System.Web.UI.C ontrol, and when used on page, it is added into the
asp.net
| page's control collection. So that ASP.NET page will know that it need to
| call your object(control) 's state management methods at the proper time.
| Actually we can find some realworld examples like the DataSource controls
| in asp.net 2.0, though they're only utility components which haven't UI
| related task, they're still designed as Control since they need to hook
| into the asp.net page's runtime event model and state management steps.
|
| Thanks,
|
| Steven Cheng
| Microsoft Online Support
|
| Get Secure! www.microsoft.com/security
| (This posting is provided "AS IS", with no warranties, and confers no
| rights.)
|
|
|
|
| --------------------
| | Message-ID: <b8************ **************@ msnews.microsof t.com>
| | From: Brock Allen <ba****@NOSPAMd evelop.com>
| | Subject: Re: IStateManager in a class object
| | References: <Op************ **@TK2MSFTNGP09 .phx.gbl>
| | MIME-Version: 1.0
| | Content-Transfer-Encoding: 8bit
| | Content-Type: text/plain; charset=iso-8859-1; format=flowed
| | X-Newsreader: JetBrains Omea Reader 671.6
| | Newsgroups: microsoft.publi c.dotnet.framew ork.aspnet
| | Date: Thu, 29 Sep 2005 14:55:26 -0700
| | NNTP-Posting-Host: host81-153-126-137.range81-153.btcentralpl us.com
| 81.153.126.137
| | Lines: 1
| | Path: TK2MSFTNGXA01.p hx.gbl!TK2MSFTN GP08.phx.gbl!tk 2msftngp13.phx. gbl
| | Xref: TK2MSFTNGXA01.p hx.gbl
| microsoft.publi c.dotnet.framew ork.aspnet:1281 15
| | X-Tomcat-NG: microsoft.publi c.dotnet.framew ork.aspnet
| |
| | Right, so you'll create the helper and it will be empty until
| LoadViewState
| | is called. That's why it's important to forward the overrides to the
| helper.
| | So, yes, ViewState won't be loaded until the Page base class calls the
| LoadViewState
| | virtual.
| |
| | -Brock
| | DevelopMentor
| | http://staff.develop.com/ballen
| |
| | > Thanks for the reply....but you lost me there. If I'm using this in a
| | > page I understand about overriding the pages LoadViewState,
| | > SaveViewState.. .and calling the helper class LoadViewState, etc...
| | > The paradox I'm lost on is how the instance of the helper is saved and
| | > reinstantiated such that the value in it's statebag persist. The page
| | > needs to instantiate the helper somewhere. And if the helper has a
| | > constructor which instantiates the statebag, the statebag (and thus
| | > the viewstate) is going to be empty.
| | >
| | > "Brock Allen" <ba****@NOSPAMd evelop.com> wrote in message
| | > news:b8******** *************** ***@msnews.micr osoft.com...
| | > This approach is typically done when a control (or the page) needs to
| | > use
| | > a helper object to track the viewstate. So the usage model is for the
| | > control
| | > to instantiate an instance of the helper object and then override all
| | > of
| | > the IStateManager APIs and call into the helper object for each one
| | > (so
| | > override
| | > LoadViewState and the call into the helper's LoadViewState, etc...).
| | > This
| | > is how the helper object gets 'hooked into' the page model. I hope
| | > that just
| | > made sense :)
| | > -Brock
| | > DevelopMentor
| | > http://staff.develop.com/ballen
| | >> I am creating a class (not a control) which implements IStateManager.
| | >> I've created the class and all of the implementations (LoadView,
| | >> SaveViewState, etc...). My Question is: How do I instantiate this
| | >> class in a page and then re-instantiate it on post back such that I
| | >> don't lose it's viewstate? If the page always uses x = new myclass
| | >> to instantiate, the myclass constructor is always going to
| | >> reinitialize its statebag.
| | >>
|
| |
| |
|
|

Nov 19 '05 #7

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