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dotnet windows forms designtime
group:Component Creation/Deletion bound to PropertyChange Problem
dotnet windows forms designtime:
as below: [Flags] public enum Parts : int { None = 0, Header = 1, HeaderDetail = 3, HeaderFooter = 5, HeaderDetailFooter = 7 } Depending on the Parts configuration chosen at designtime, I will be creating/destroying the associated components (Header, Detail or Footer). As such, I am just attaching a custom eventhandler on the property set method since it is logical that the whole implementation is associated with the property change. The problem is with regard to the undo/redo feature of VS. For example, when I changed from HeaderFooter to Header, the Footer component is removed from my custom containercontrol and destroyed from the form surface through the designerhost after the property set. When I Redo the property change, VS tries to recreate the destroyed component since it was part of the property change transaction then after that comes the property change which has my handler to create a Footer component and then add it to my containercontrol. The additional component gets created in the form and gets code gen'ed which basically has no function since it was not added to any control collection. I need some views perhaps there is wrong with my design. Is it possible to have a check in the end so I can destroy again the dummy components created by undo? But then this will be costly and not ideal. Or perhaps I just disable the undo/redo feature for the said property change? Please help... -- Joey Calisay http://spaces.msn.com/members/joeycalisay/
I am not sure if this point can help your (i don't understand very well your
scenariio) but When you want create or destroy a component in design mode you must use the IDesignerHost.CreateComponent or IDesignerHost.DestroyComponent method. example of code : protected override DataGridItemExtenderBase NewItem(DataGrid dataGrid, DataGridItemExtenderBase item) { DataGridColumnExtender result; #if DESIGN System.ComponentModel.Design.IDesignerHost dh = dataGrid.GetDesignerHost(); if (dh != null) { result = (DataGridColumnExtender)dh.CreateComponent(typeof(DataGridColumnExtender)); result.MappingName = item.MappingName; } else #endif result = new DataGridColumnExtender((DataGridColumnExtender)item); return result; "joeycalisay" <hcalisay@_spamkiller_codex-systems.com> a écrit dans le message de news:uVGLWhXGFHA.464@TK2MSFTNGP15.phx.gbl... [quoted text, click to view] > I have a custom enum property Parts for my custom containercontrol declared > as below: > > [Flags] > public enum Parts : int > { > None = 0, > Header = 1, > HeaderDetail = 3, > HeaderFooter = 5, > HeaderDetailFooter = 7 > } > > Depending on the Parts configuration chosen at designtime, I will be > creating/destroying the associated components (Header, Detail or Footer). As > such, I am just attaching a custom eventhandler on the property set method > since it is logical that the whole implementation is associated with the > property change. > > The problem is with regard to the undo/redo feature of VS. For example, when > I changed from HeaderFooter to Header, the Footer component is removed from > my custom containercontrol and destroyed from the form surface through the > designerhost after the property set. When I Redo the property change, VS > tries to recreate the destroyed component since it was part of the property > change transaction then after that comes the property change which has my > handler to create a Footer component and then add it to my containercontrol. > The additional component gets created in the form and gets code gen'ed which > basically has no function since it was not added to any control collection. > > I need some views perhaps there is wrong with my design. Is it possible to > have a check in the end so I can destroy again the dummy components created > by undo? But then this will be costly and not ideal. Or perhaps I just > disable the undo/redo feature for the said property change? Please help... > > -- > Joey Calisay > http://spaces.msn.com/members/joeycalisay/ > > >
Hello Joey,
I don't think it is a good idea to use a property set event handler this way. Typically, you would either "shadow" the property in a custom designer (PreFilterProperties, etc) or subscribe to the ComponentChanged event (IComponentChangeService). It could be that if you use this instead, you will be rid of the problem. But I don't think so. A more fundamental question is how to handle dependent properties in general. A dependent property is modified when another property is modified. If the dependent property is not serialized, there is no problem. In your case, it is not a dependent property, but a dependent component creation. Because it is a component known to the root designer, it must be recorded in the designer transaction. And it is serialized. Essentially it is a similar problem to dependent properties. I am not sure of the best solution, but you may want to either prevent serialization of the parts configuration, or make the footer component not an IComponent, but simply a property in another object. In either case, one change (parts) or the other (footer) must not be recorded in the designer transaction, so you don't get a "double change" on playback. When you use dependent properties, only a single property change should be recorded. Regards, Frank Hileman check out VG.net: http://www.vgdotnet.com Animated vector graphics system Integrated Visual Studio .NET graphics editor [quoted text, click to view] "joeycalisay" <hcalisay@_spamkiller_codex-systems.com> wrote in message news:uVGLWhXGFHA.464@TK2MSFTNGP15.phx.gbl... >I have a custom enum property Parts for my custom containercontrol declared > as below: > > [Flags] > public enum Parts : int > { > None = 0, > Header = 1, > HeaderDetail = 3, > HeaderFooter = 5, > HeaderDetailFooter = 7 > } > > Depending on the Parts configuration chosen at designtime, I will be > creating/destroying the associated components (Header, Detail or Footer). > As > such, I am just attaching a custom eventhandler on the property set method > since it is logical that the whole implementation is associated with the > property change. > > The problem is with regard to the undo/redo feature of VS. For example, > when > I changed from HeaderFooter to Header, the Footer component is removed > from > my custom containercontrol and destroyed from the form surface through the > designerhost after the property set. When I Redo the property change, VS > tries to recreate the destroyed component since it was part of the > property > change transaction then after that comes the property change which has my > handler to create a Footer component and then add it to my > containercontrol. > The additional component gets created in the form and gets code gen'ed > which > basically has no function since it was not added to any control > collection. > > I need some views perhaps there is wrong with my design. Is it possible to > have a check in the end so I can destroy again the dummy components > created > by undo? But then this will be costly and not ideal. Or perhaps I just > disable the undo/redo feature for the said property change? Please help... > > -- > Joey Calisay > http://spaces.msn.com/members/joeycalisay/ > > >
Thanks a lot for the reply azerty but I am well aware of the said method and
I referred to it in my post as "creation through the designerhost". -- Joey Calisay http://spaces.msn.com/members/joeycalisay/ [quoted text, click to view] "azerty" <azerty@aaaa.fr> wrote in message news:Ox0TqTfGFHA.2524@TK2MSFTNGP15.phx.gbl... > I am not sure if this point can help your (i don't understand very well your > scenariio) > > but When you want create or destroy a component in design mode you must use > the IDesignerHost.CreateComponent or IDesignerHost.DestroyComponent method. > > example of code : > > protected override DataGridItemExtenderBase NewItem(DataGrid dataGrid, > DataGridItemExtenderBase item) > { > DataGridColumnExtender result; > #if DESIGN > System.ComponentModel.Design.IDesignerHost dh = > dataGrid.GetDesignerHost(); > if (dh != null) > { > result = > (DataGridColumnExtender)dh.CreateComponent(typeof(DataGridColumnExtender)); > result.MappingName = item.MappingName; > } > else > #endif > result = new DataGridColumnExtender((DataGridColumnExtender)item); > > return result; > > > "joeycalisay" <hcalisay@_spamkiller_codex-systems.com> a écrit dans le > message de news:uVGLWhXGFHA.464@TK2MSFTNGP15.phx.gbl... > > I have a custom enum property Parts for my custom containercontrol > declared > > as below: > > > > [Flags] > > public enum Parts : int > > { > > None = 0, > > Header = 1, > > HeaderDetail = 3, > > HeaderFooter = 5, > > HeaderDetailFooter = 7 > > } > > > > Depending on the Parts configuration chosen at designtime, I will be > > creating/destroying the associated components (Header, Detail or Footer). > As > > such, I am just attaching a custom eventhandler on the property set method > > since it is logical that the whole implementation is associated with the > > property change. > > > > The problem is with regard to the undo/redo feature of VS. For example, > when > > I changed from HeaderFooter to Header, the Footer component is removed > from > > my custom containercontrol and destroyed from the form surface through the > > designerhost after the property set. When I Redo the property change, VS > > tries to recreate the destroyed component since it was part of the > property > > change transaction then after that comes the property change which has my > > handler to create a Footer component and then add it to my > containercontrol. > > The additional component gets created in the form and gets code gen'ed > which > > basically has no function since it was not added to any control > collection. > > > > I need some views perhaps there is wrong with my design. Is it possible to > > have a check in the end so I can destroy again the dummy components > created > > by undo? But then this will be costly and not ideal. Or perhaps I just > > disable the undo/redo feature for the said property change? Please help... > > > > -- > > Joey Calisay > > http://spaces.msn.com/members/joeycalisay/ > > > > > > > >
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