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Hi folks!

I am developing a custom TreeView and I have got a problem with the
serialization of my TreeViewModel:

[Serializable]
public class NavigationTreeModel : ITreeModel {

public event EventHandler DataChanged;

private Folder _rootFolder;
private IList _rootElements;

public NavigationTreeModel() : this(null) {
}

public NavigationTreeModel(Folder root) {
_rootElements = new ArrayList();
RootFolder = root;
}

public Folder RootFolder {
get { return _rootFolder; }
set {
if (_rootFolder == value)
return;
if (_rootFolder != null)
_rootElements.Remove(_rootFolder);
_rootFolder = value;
if (_rootFolder != null) {
_rootElements.Add(_rootFolder);
}
OnDataChanged(EventArgs.Empty);
}
}

#region ITreeModel Member

public IList RootElements {
get {
if (_rootElements == null) {
_rootElements = new ArrayList();
if(RootFolder != null)
_rootElements.Add(RootFolder);
}
return _rootElements;
}
}

public IList GetChildren(object parent) {
if (parent is Folder) {
return ((Folder)parent).Folders;
}
return new ArrayList();
}

#endregion

protected virtual void OnDataChanged(EventArgs e) {
if (DataChanged != null)
DataChanged(this, e);
}
}

The model serializes perfectly until I set my TreeViewControl to handle its
DataChangedEvent. Then I get the following exception:
"Der Typ 'julitec.DM.Web.NavigationTreeModel' muss als 'Serializable'
markiert sein oder einen anderen TypeConverter als ReferenceConverter
haben." (= The type 'julitec.DM.Web.NavigationTreeModel' must be marked as
Serializable or have a TypeConverter other than ReferenceConverter)
I guess that is because my TreeViewControl is not serializable.
What I am asking myself (and you) now is the following: Should I really make
a Control serializable? I don't think it is a good pratice to do so since
none of the built in ASP.NET WebControls seems to be serializable. What else
could I do to overcome this problem?

Thanx in advance!



Greetings, Ralf

hi leon!

my problem is that i want to notify my control of changes that occur to the
model - not the other way round
but i have got no idea how to send an event or any kind of notifcation to my
control if i can't let it handle my model events because it is not
serializable...

could you give me an example of what you where proposing?


ralf


"Leon Friesema" <leon@@frostbits.nl> schrieb im Newsbeitrag
news:...
> On Tue, 14 Dec 2004 09:46:28 +0100, "Ralf Müller" <>
> wrote:
>
> >Hi folks!
> >
> >I am developing a custom TreeView and I have got a problem with the
> >serialization of my TreeViewModel:
> >
> [SNIP CODE]
> >
> >The model serializes perfectly until I set my TreeViewControl to handle
its
> >DataChangedEvent. Then I get the following exception:
> >"Der Typ 'julitec.DM.Web.NavigationTreeModel' muss als 'Serializable'
> >markiert sein oder einen anderen TypeConverter als ReferenceConverter
> >haben." (= The type 'julitec.DM.Web.NavigationTreeModel' must be marked
as
> >Serializable or have a TypeConverter other than ReferenceConverter)
> >I guess that is because my TreeViewControl is not serializable.
> >What I am asking myself (and you) now is the following: Should I really
make
> >a Control serializable? I don't think it is a good pratice to do so since
> >none of the built in ASP.NET WebControls seems to be serializable. What
else
> >could I do to overcome this problem?
> >
> >Thanx in advance!
> >
> >
> >
> >Greetings, Ralf
> >
>
> That indeed is the problem, the control isn't serializable and no, you
> don't want it to be.
> What you want to do, if you want to serialize the data is handle the
> control and data seperately. When a change has occured in the Control,
> you post it back to your data and serialize that.
> One minor problem though, when de-serializing you need to rewrite your
> code because it needs to repopulate the control.
>
> Leon.

First of all - Merry Xmas!

My Problem is that I've got one TreeModel and several TreeViews attached to
it. In the meanwhile I "solved" the problem storing my Model in the
Session-Collection so it does not have to be serialized on postback. But
still it would be interesting how to implement the MVC-Pattern correctly in
ASP.NET. But I guess I'd better put that in a new Post...

Greetings, Ralf


"Leon Friesema" <leon@@frostbits.nl> schrieb im Newsbeitrag
news:...
> On Thu, 16 Dec 2004 12:39:36 +0100, "Ralf Müller" <>
> wrote:
>
> >
> >
> >"Leon Friesema" <leon@@frostbits.nl> schrieb im Newsbeitrag
> >news:.. .
> >> On Tue, 14 Dec 2004 09:46:28 +0100, "Ralf Müller" <>
> >> wrote:
> >>
> >> >Hi folks!
> >> >
> >> >I am developing a custom TreeView and I have got a problem with the
> >> >serialization of my TreeViewModel:
> >> >
> >> [SNIP CODE]
> >> >
> >> >The model serializes perfectly until I set my TreeViewControl to
handle
> >its
> >> >DataChangedEvent. Then I get the following exception:
> >> >"Der Typ 'julitec.DM.Web.NavigationTreeModel' muss als 'Serializable'
> >> >markiert sein oder einen anderen TypeConverter als ReferenceConverter
> >> >haben." (= The type 'julitec.DM.Web.NavigationTreeModel' must be
marked
> >as
> >> >Serializable or have a TypeConverter other than ReferenceConverter)
> >> >I guess that is because my TreeViewControl is not serializable.
> >> >What I am asking myself (and you) now is the following: Should I
really
> >make
> >> >a Control serializable? I don't think it is a good pratice to do so
since
> >> >none of the built in ASP.NET WebControls seems to be serializable.
What
> >else
> >> >could I do to overcome this problem?
> >> >
> >> >Thanx in advance!
> >> >
> >> >
> >> >
> >> >Greetings, Ralf
> >> >
> >>
> >> That indeed is the problem, the control isn't serializable and no, you
> >> don't want it to be.
> >> What you want to do, if you want to serialize the data is handle the
> >> control and data seperately. When a change has occured in the Control,
> >> you post it back to your data and serialize that.
> >> One minor problem though, when de-serializing you need to rewrite your
> >> code because it needs to repopulate the control.
> >>
> >> Leon.
> >
>
> >hi leon!
> >
> >my problem is that i want to notify my control of changes that occur to
the
> >model - not the other way round
> >but i have got no idea how to send an event or any kind of notifcation to
my
> >control if i can't let it handle my model events because it is not
> >serializable...
> >
> >could you give me an example of what you where proposing?
> >
> >
> >ralf
>
> Ralf,
>
> what do you mean by notify my control?
> If you mean you added a Node to the TreeView == change to the Model.
> In that case, why don't you override the methods of the node-changes
> (add, remove, etc) and handle these events also within your
> (serializable) model.
>
> Leon.