在 Silverlight 和“plain vanilla”.Net 之间共享程序集

Question

I'm using some generic classes as data containers, and am using them to pass data to and from a wcf service. Because of the way WCF mangles generic names on the client side into a class named something like "ListOfBlah231546797646", I'm adding a reference to the real assembly as a "KnownType".

Silverlight needs to consume these services, but can only reference "silverlight assemblies". I've moved the classes to their own "silverlight assembly" and can reference them from silverlight, but when the service runs I get a "cannot find referenced assembly" error on the System.Runtime.Serialization assembly.

It turns out that Silverlight has it's own set of binaries, all labelled version 2.0.5.0. These aren't in the service's GAC and therefore the exception is thrown.

Because of this I can't reference my "Silverlight Assembly" from my service's code. Is there any way I can get around this issue, making the two flavors cross compatible when they get serialized?

This question is similar, but none of the answers help. Any ideas? similar question

Answer 1

The way I share code between Silverlight and normal CLR, is to use the "add as link" feature with C# projects. So it ends up looking like this:

| SilverlightLib
|   File1.cs
|   File2.cs
| ClrLib
|   File1.cs <as link>
|   File2.cs <as link>

Then VS works fine, and both sets of code get compiled. The annoying part is where the Silverlight framework doesn't line up. (WCF has some parts that don't exist in SL.) In that case, you'll need to use the preprocessor "#if SILVERLIGHT" to make the code target both platforms.

This has worked pretty well so far. This way, I can write code, test with VSTS, but still have it work on SL from the same source. A few tips:

• Always edit from the SL project -- this way the editor will limit to SL, and you won't get surprises later on.
• Sometimes you have to close the opened file for Intellisense to update in the other project.

Answer 2

There are two ways that I've done this in the past.

First and easiest. Add the WCF Service as a ServiceReference into Silverlight. This will take care of regenerating all the class libraries and refreshing them when needed.

Second, store two copies of the classes, one in silverlight and one in the .net 3.5 clr. Then ensure that the DataContract Names and Namespaces match. If you add the ServiceReference in silverlight then in explorer view the ServiceReference folder and look at the Reference.cs file you'll see the classes generated and can copy those.

Answer 3

Not sure if it is possible in your scenario, but have you thought about providing your objects serialized as Json to your silverlight client? Then in your silverlight app you can use theJsonObject in silverlight. That way you avoid having another set of model objects in your silverlight app.

JsonObject user = (JsonObject)JsonObject.Load(responseStream);
bool isMember = user["IsMember"];
string name = user["Name"];
int age = user["Age"];

The example is from this msdn sample

The nice thing about this approach is also that you have linq support in silverlight, and this is usable by your ajax clients as well. It is also more secure than exposing your real objects to the silverlight app running on the client.