Can I use a custom control in a stand-alone XAML file?

Question

Quick intro: I have some Silverlight 1 content that people have been editing and putting into HTML pages. Unfortunately, this means a lot of repetative creation of Storyboards, etc. We can use Silverlight 2, but not everyone here is familiar with C#/has Visual Studio. What I would like to do is create some custom controls in C#, output to a DLL, then reference the DLL in the XAML file (just as if it was part of a Silverlight project in VS).

I've tried adding this:

xmlns:mycontrol="clr-namespace:MyControl;assembly=../../content_GLOBAL/controls/MyControl/MyControl"

in the Grid tag that is my root. I know the path to MyControl.dll is correct. When I actually try and use it, though (I add <mycontrol:MyControl></mycontrol:MyControl> to the grid) and I get a parser error. It all seems OK if I don't add the control, even if I leave in the xmlns.

I suppose on some level, this makes sense--looking for an assembly is useful if you are going to build something, and since this XAML isn't in VS, it isn't actually building anything. Is there another way that I can reference, and use a custom control in SL2 in a stand-alone XAML file?

Answer 1

Let me first make sure that I understand you correctly: You have a Silverlight app that doesn't use any managed code and is not packaged in a .xap file. The <object> tag refers to a loose xaml file.

This is the Silverlight 1 app model and can still be used in SL 2, and such apps are referred to as "v1-style apps" (even though they target SL 2 and may use features not present in v1). When an application in this form is used, the Silverlight plugin does not load any of the managed components of the runtime (e.g. the CLR, etc.), so referencing a dll from a v1 style app is not going to work.

However, there might be work-arounds to the challenge you are facing here. One solution might be to use a v2 style app that is packed into a .xap and uses managed assemblies. One of the reasons you gave for not doing this is that other developers one the team are not familiar with C#. This should not be an issue as C# is not a requirement for building apps in SL, you can continue to program against it in JavaScript. And if you are just writing JavaScript code, Visual Studio is not a requirement, since there is nothing to compile. They can just edit the .html/.js files and use the .xap/.dll files that were already compiled. Does this make sense?