Resource in Silverlight , A Brief OverView - Part 1 (Resource Files)

The complete information on resources will span across multiple posts ,where we will cover Binary Resource (Resource Files ) and XAML Resource .

Various Ways of managing Resources

In Silverlight Resources can be managed by following ways

• Resource at server Side ,Loading on Demand
• Resource embedded inside XAP/Assembly
• Resources from external assemblies

The most important point ,we should not confuse over Assembly Resource and XAML Resource although both termed as resource .We can divide resource types in to two categories

• Files other than executable or Binary/Assembly Resource (Managed through Resource Files)
• Objects such as Styles,Templates etc.. or XAML Resource(Managed Through Resource Dictionary)

Basically the scope of this post is to give you a brief about Resource Files or Binary Resource or Assembly Resource .In this post we will explore how these resource files can be stored and managed from Silverlight .The subsequent post will focus on Resource Dictionary or XAML Resource.

Managing Resource Files

Before moving on the Resource Files lets have quick look into some important terminologies we will come across frequently

Application Package - The files packaged as a XAP file which includes the Silverlight assemblies and Application manifest files also Resources if any.

Application Root - The location where XAP files reside in the deployed solution most of the time ClientBin

URI - Stands for Uniform Resource Identifier , is the path to the the Resource.It can be either

Absolute URI	Relative URI
Exact location of the Resource for .eg. a qualified URL (www.manaspatnaik.com/image1.jpg)	Location of file with respect to the application root (Where Application package resides)For e.g. "/image1.jpg"
Used when files are other than application root	A common scenario of storing resource with in the domain under application root
	Files must be inside the same application root folder where package exists.

The application root is the folder where the application package XAP file resides.So all the files must be with in the same folder as XAP file .The relative URI does not look for content outside this folder but its does support folder structure inside the application root.So we can have our file image1.jpg inside Resource folder inside application root folder.

Other than Uri there is BuildAction property for each files which we will discover as we go through with a sample as follows.

Resource File

As we know Silverlight application is nothing but a package of files compressed and stored as single file.Any resource added to the client side inside the Silverlight project will transfer be transferred to client side based on the Mode of Deployment.Lets check with the example as bellow ,

Mode Of Deployment , BuildAction

Here the most important to note how the resource is configured for deployment by default the file's BuildAction properties set as a Resource.Silverlight does offer various options which can be handy at some time.


Generally the resources can be be deployed with following options BuildAction as

• Content
• Resource
• None

with each option the application package and the URI defers.Also make a note that in Silverlight project, although there are various options but only above mentioned build actions can be used.

Content -:

Content option add the file to application package as loose resource .



Here in the project Change the file BuildAction as Content and Rebuild the solution.The XAP file size is almost 42 KB which includes Image .

Here to locate the resource file you can follow either of the method mentioned ,
XAML :
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Code :

1	image1.Source = new BitmapImage(new Uri("/BananaTECH.jpg",UriKind.Relative));

Resource:
This Option will add the resource with in the application package inside the Silverlight assembly .



On Rebuilding the project after changing the BuildAction type of image , the XAP file size remain same 43 KB but the image is embedded inside the MySilverlightApp.dll.You can mark the difference in size of assembly compared to above content type.

To locate the resource there should not be any  leading trails .
XAML :
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Code :
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1	image1.Source = new BitmapImage(new Uri("BananaTECH.jpg", UriKind.Relative));

None:
This option neither add the resource to the application package nor to the Silverlight assembly.You need to add resource to the server manually.
With None build action the XAP file size reduced dramatically as the resource is not embedded inside the package or assembly.The screenshots bellow shows the XAP file with 4 KB of size.To make your deployed code working we need to place the resource file inside the published project under clientbin.

XAML :
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Code :
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1	image1.Source = new BitmapImage(new Uri("BananaTECH.jpg", UriKind.Relative));

Resource from an external assembly

Its wise to refactor the resource into a separate assembly for reuse amongst the applications.The best example of external assembly for resource is the theme libraries.The Silverlight too support using external Silverlight assemblies in projects .Lets create a Silverlight assembly project ,


Then adding a reference to the Silverlight project will allow you to use the resource file inside the application.



Resources can be used by using following syntax - /assemblyName;component/resourceLocation.For example in this project the image file from MyResources assembly can be fetched with URI "/MyResources;component/Rupees.jpg".The component here is the keyword.
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Conclusion

Hope this post will give you a clear idea about Resource Files .The subject Resource is not complete yet ,here we discussed only about Files/ Binaries how over lot more to discuss and share.In my subsequent posts i will try to cover more about this topic.Send me you suggestions and queries.

Source Code

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