I have a unique development situation and would like some input from others.
I have a situation where I need to load loose xaml files within a rich client application.
A given loose xaml file may have references to an assembly not currently loaded in memory
so the referenced assembly is loaded before the loading the loose xaml. The loose xaml and tied
assemblies are stored on different backend servers which are downloaded to the client and
loaded dynamically.
The loose xaml and/or assemblies are version specific and unfortunately the application can
not be shutdown between rendering xaml.v1 with assembly.v1 from server A
and xaml.v1 with assembly.v2 on server B.
Both assemblies use the same namespace declaration so "older" assemblies can still
work with "newer" ones for any given loose xaml.
The problem is, I do not get a reference to assembly.v2 if I load xaml.v2 which contains
references to "newer" features in assembly.v2.
I obviously cannot unload assembly.v1 from the app domain and I'm not sure if I can
reference items in xaml that are loaded within a different app domain through marshalling.
Any Ideas other than using different namespace references?
I'm guessing that you are already doing dynamic assembly resolution and loading? If so, then you could try substituting a fake assembly name in place of the real assembly name i n the Xaml - you can then use that in your assembly resolution code to load up and return the right assembly. e.g. if your original source Xaml is:
xmlns:myassembly="clr-namespace:MyApp.MyAssembly;assembly=MyAssembly"
and you know that Xaml wants v2 of MyAssembly, replace the assembly ref in the Xaml string before parsing it to:
xmlns:myassembly="clr-namespace:MyApp.MyAssembly;assembly=MyAssembly.v2"
.. then in your assembly resolution / load code, when you see the ".v2" bit on the end you look for and load that assembly instead.
Please let me know if I've misunderstood the question, or you aren't current doing any custom assembly resolution - that would certainly be the key in this situation I think.
Another option (assuming that you are versioning your assemblies properly) is to simply include the assembly version in the ns declaration, like so:
xmlns:ns0="clr-namespace:MyCompany.MyProject.MyNameSpace; Assembly=MyCompany.MyProject, Version=1.0.0.0"
I haven't confirmed if this would work, but I believe that it may. You could use the XmlnsDefinitionAttribute (at assembly level). E.g.
Assembly V1 -> AssemblyInfo.cs
[assembly: XmlnsDefinition( "http://schema.mycompany.com/myproject/v1", "MyCompany.MyProject" )]
Assembly V2 -> AssemblyInfo.cs
[assembly: XmlnsDefinition( "http://schema.mycompany.com/myproject/v2", "MyCompany.MyProject" )]
And then in xaml:
xmlns:myassembly="http://schema.mycompany.com/myproject/v2"
Related
I have a .xaml UserControl named MyUserControl.xaml and I want to set its resource URI.
Per default, WPF generates a URI that includes a resource name, which is equal to the resource it belongs to such as
"/MyNamespace;component/myusercontrol.xaml"
for the .xaml named MyUserControl.xaml
How can I have a UserControl MyUserControl.xaml and make WPF generate an individual resource identifies such as
"/MyNamespace;component/myusercontrol_A.xaml" or
"/MyNamespace;component/myusercontrol_B.xaml" ?
The reason why I want to do that is described here.
In the image below you can see the resource identifier I am talking about:
and therein:
Note, that that question is the origin of this question and might help to understand its background.
After a week suffering and laboring with this issue, I finally found both the reason for the problem and its solution.
The problem lies within the auto-generated *.g.i.cs file, which is called by the InitializeComponent() method of a UserControl, as seen by the following:
This file generates a string (a Resource Locator) that expresses the path to that xaml-component, as seen by the following:
Now, if you have multiple versions of the same assembly and both versions include the same xaml-file, WPF does not know what xaml-file to instantiate, because the Resource Locator only references the name of the assembly but not its version.
This results in a TargetInvocationException, saying that
{"The component 'MyNamespace.MyUserControl' does not have a resource identified by the URI '/MyAssembly;comoponent/myusercontrol.xaml'"}
as follows:
The simple (but most definitely not obvious) solution for this is to add the version of the assembly to this Resource Locator. This can be achieved by modifying the build-file of the project by adding the <AssemblyVersion>-tag as follows:
Credits for this go to:
this blog
this SO thread
I'm following a tutorial from here:
http://www.wpftutorial.net/LocalizeMarkupExtension.html
and everything works fine....Untill I devide my code in to different projects
So I have a class (TranslateExtension) that inherits from MarkupExtension. this allows me to add markup like this to WPF:
<TextBlock Text="{Mynamespace:Translate key1}" Margin="8" ></TextBlock>
and the textblock gets filled in with the necessary text
But when i want to put the front end in a different project I get the following exceptions:
The name "Translate" does not exist in the namespace
The type "Translate" was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built
The tag "Translate" does not exist in XML namespace ....
I already have added a reference to the namespace on top of my XAML file and the namespace exists inside of the new project. I also have a reference from my Front end to my old project.
So everything works fine untill I extract the front end in to a different project....
IMPORTANT: If I take TranslateExtensions and Put it in the front end, with everything else in the old project, things magically work...
any ideas?
XAML namespaces starting with clr-namespace: are specific to an assembly. If you don't specify the assembly name, the current assembly is assumed.
The simplest option will be to use an assembly-qualified namespace:
xmlns:MyNamespace="clr-namespace:MyNamespace;assembly=MyAssembly"
For a more robust solution, you might want to look at the XmlnsDefinitionAttribute, which can be used to map multiple CLR namespaces across different assemblies to a single XML namespace URI.
I have an composite application which has a Shell window and has some modules, each module is loaded on to the shell using MEF (Microsfot Prism). Shell Itself has a resource file default(Resource.resx) and for other languages(like Resource.ar-SA.resx) too to support Localilzation.
For Xaml : I had used x:Static Resource.KeyName
In c# Code : I had used GetString(keyName, culture) to get the required string.
To support Localization, I have added a line of code which gets the current culture of the system and loads the required Resx File.
For Setting the Current Culture.
Resource.Culture =
new System.Globalization.CultureInfo(System.Globalization.CultureInfo.CurrentCulture.Name);
in App.Xaml.cs
All these work Completely fine.
Similarly, each module which is loaded using MEF has Resource files as mentioned above. But in case of Modules, resource Key defined in the Xaml for a specific language file is not working. Its always getting the values from the Default (Resource.Resx) file. But any key used in the code using ResourceManager class works fine.
I ended up keeping all my resources in an "Infrastructure" project so all the resources are loaded from one place, it just made it simpler.
My xaml bindings look like this
Get the refrence to your resx class.
xmlns:resources="clr-namespace:Infrastructure.resources;assembly=Infrastructure"
now get the text
Content="{x:Static resources:Resources.Activity_Regarding}"
You might be doing this already but I cant see. You would want to make sure the namespace matches for the resx you want to use. So your modules namespace.
We have multiple namespaces and assemblies in my project, and so many xmlns to declare in each control we make (at least 7, without system ones like x: or d:). It's so tedious.
Is there a way to declare xmlns once for all in the application ?
If not, do you have some workarounds (in order to have a lightweight control definition) ?
Please note that I know XmlnsDefinitionAttribute, it's not always possible (with external ssemblies for example) or not a great design (for me it's not a great design to put an UI specific attribute in a business entity assembly).
xmlns are a document level thing needed by the compiler, they are like using statements which you will also have to place in every C# code file.
If you have many common xmlns you could create an item template for Visual Studio which adds them by default, or find an extension which allows for something like Snippets in XAML.
Using the merged resource dictionaries degrade application performance. In my assembly I often need to use merged resource dictionaries. I want to combine resources in one dictionary, and delete the original baml. I can't set Build Action to None (instead of Page), because in this case I lose some functionality (e.g., no syntax highlighting by resharper). How can I do this?
At run-time your application still need to read the linked BAML resources files, for this reason you can't remove BAML from your assembly.
For example:
You merge the following resource dictionaries
dictionary1.xaml
dictionary2.xaml
in merged.xaml.
You cannot simply remove the compiled XAML (BAML - dictionary1.baml and dictionary2.baml), because, as I wrote, at run-time you still need these resources.
But, anyway, you could literally copy the content of your XAML resources on merged.xaml, in this way you will have only merged.baml (after the compiler has generated it in your assembly resource part).