Porting from WPF to Silverlight: The Missing Pieces, Part 1
Recently I’ve been working on a port of a WPF 3.5 application into a Silverlight 3 web application. I came across many of the limitation of Silverlight 3 relative to WPF 3.5.
Fortunately, I’ve found numerous excellent solutions throughout the blogosphere.
These have helped me so much I would like to note them for all to see.
Also, this list might come in handy to other people porting applications from WPF to Silverlight.
One final note, the port was done from WPF 3.5 to Silverlight 3. Some of the issues might been solved in Silverlight 4 or have different solutions.
No Commands
Description: Silverlight 3 lacks proper support for commands.
Although Silverlight 3 does have the definition of ICommand, the buttons doesn’t have a Command property to bind with.
Solution by: Patrick Cauldwell
http://www.cauldwell.net/patrick/blog/MVVMBindingToCommandsInSilverlight.aspx
In a nutshell:
Instead of writing:
<Button
Content="Say Hello"
Command="{Binding Path=SayHello}"
/>
Use the code in the post and write:
<Button
Content="Say Hello"
my:ButtonService.Command="{Binding Path=SayHello}"
/>
No ClipToBounds
Description: Silverlight 3 lacks support for ClipToBounds.
Solution by: Colin Eberhardt
http://www.scottlogic.co.uk/blog/colin/2009/05/silverlight-cliptobounds-can-i-clip-it-yes-you-can/
In a nutshell:
Instead of writing:
<Grid
Background="Yellow"
Margin="20,40,-20,20"
ClipToBounds="True"
>
...
</Grid>
Use the code in the post and write:
<Grid
Background="Yellow"
Margin="20,40,-20,20"
util:Clip.ToBounds="True"
>
...
</Grid>
No DataContextChanged Event
Description: Silverlight 3 doesn’t have the DataContextChanged event
Solution by: Emiel Jongerius
http://www.pochet.net/blog/2010/06/16/silverlight-datacontext-changed-event-and-trigger/
In a nutshell:
Instead of writing:
MyControl.DataContextChanged += MyControl_DataContextChanged;
Use the code in the post and write:
DataContextChangedHelper.AddDataContextChangedHandler(MyControl, MyControl_DataContextChanged);
No DataTrigger
Description: Silverlight 3 doesn’t have data triggers, it uses a completely different model, using VisualStateManager
Solution by: Pete Blois
http://blois.us/blog/2009/04/datatrigger-bindings-on-non.html
In a nutshell:
Instead of writing:
<DataTrigger Binding="{Binding IsLoaded}" Value="True">
... DOING STUFF
<DataTrigger>
Use the code in the post and write:
<i:Interaction.Behaviors>
<id:DataStateSwitchBehavior Binding='{Binding IsLoaded}'>
<id:DataStateSwitchCase Value='True' State='Loaded'/>
</id:DataStateSwitchBehavior>
</i:Interaction.Behaviors>
Of course, you should define a state that does the same “STUFF”.
The transition is not immediate, but at least it provide the same functionality as data triggers.
To be continued..
That’s it for now,
Arik Poznanski.