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C# Q.3 : Level 300

What is the relation or difference between delegate and event?

Note : Dont describe the definitions of delegates and events. You techie guys, describe them in real techie way.

C# Q.2 Thought on Probing

Probing is the process of locating the referenced assembly. How runtime locates the referenced assembly is an interested part to learn. Knowing the probing process is helpful to configure your assemblies such that you will gain that slightest performance in your applications. That said, probing is one step in the series of steps in Fusion process. Fusion includes finding, locating and loading the referenced assembly.

1. Runtime checks for any binding redirections in the configuration file. If there are any, it just searches in the specified path and throws an exception if not found. Check here on how to set binding redirections.
2. Next It checks Publisher Policy file to see if there are any policies exist. A publisher policy file is used when a shared component is updated and the new version of the shared component should be picked up by all applications using that component. Check here on how to create policy files.
3. Now, runtime checks if the requested assembly has already been requested in previous calls, if so, CLR uses the loaded assembly.
4. Runtime checks if requested assembly is a strong-named assembly. Only then, it checks if GAC has the requested assembly.
5. By now, runtime has decided which assembly to load and hence starts the probing process. The order of the folders it uses to probe is application base folder (root location), culture specific in application base folder s (en-US and en), next in private bin paths, and culture specific folders in private bin paths.

Understanding this, we can conclude that having binding redirections would give the performance gain in loading the assembly, which avoids probing process. But analyze the pros and cons of it, because locale specific fall back mechanism will not apply. Using configuration file is like blindly using a path. Use it whereever you feel like it can serve the purpose.

C# Q.2 : Level 300

Order these steps involved in Probing for the assembly specified below.

Assembly Name : testAssembly.dll
Application Root : http://www.sampletest.com
Culture : hi-IN

Note : Assume that this assembly is not present in the GAC and also no binding redirections found in config file. Also, answer must include all steps, meaning assembly will be available in the last step.

A) http://www.sampletest.com/IN/testAssembly.dll
B) http://www.sampletest.com/bin/hi-IN/testAssembly.dll
C) http://www.sampletest.com/hi-IN/testAssembly/testAssembly.dll
D) http://www.sampletest.com/bin/IN/testAssembly/testAssembly.dll
E) http://www.sampletest.com/bin/hi-IN/testAssembly/testAssembly.dll
F) http://www.sampletest.com/bin/IN/testAssembly.dll
G) http://www.sampletest.com/IN/testAssembly/testAssembly.dll
H) http://www.sampletest.com/hi-IN/testAssembly.dll

C# Q.1 : Level 300: Answer

Answer C

To briefly describe on Assembly Manifest, assembly manifest is a place holder for assembly wide attributes such as name, version, culture, referenced assembly list and etc. As assembly contains one or more modules. In Multi-module assembly, the module which contains the manifest is called primary module. In this case, manifest also contains references to other modules.

Assembly manifest includes publickeytoken, version number for each referenced assembly, references to the assembly attributes such as AssemblyCopyrightAttribute and all, and it also contains assembly resources section. Compiler adds referenced assemblies to assembly manifest only when any of the types being used. That is the reason, even if references add thru Add Reference, or namespaces included with using keyword, compiler doesnt add referenced assembly information to assembly manifest unless the referring assembly uses atleast of the types in referred assembly.

C# Q.1 : Level 300

When is a referenced assembly added to Assembly Manifest?

A) When an assembly is added to the referenced assembly list using VS.Net -> References - > Add Reference.
B) When the namespace within the referenced assembly is included in "using" list.
C) When any of the types of referenced assembly being used in parent assembly.

Note : Level 100 -> simple and Level 500 - God Level.

C# Quiz

As an initiative to learn and share C#, I will post a question on C# every day. You can provide comments with answers and explanations. The answer to question will be provided with next question.
This would enlighten us to learn nitty gritty details of the language that we admire. Thats not all. Biweekly I shall publish the number of correct answers for each participant. I also welcome you to contribute to the questions.

What do you think? Please give your thought on this.

Yukon Resource

Yukon XML is a very good resource on Yukon. It has lot of information on variety of topics on Yukon, articles, chapters from Books, links to other good resources and UGs and many more...This site looks real professional..i mean it. thankx to Darshan.

Query Analysis - Here is a Tool

Here is one more tool added to tool box on my web site. This one helps you analyze SQL queries and gives list of recommendations to tune the query. Check out for the analysis-friendly display of query plan and critical processing steps (high on cost).

Article on T-SQL Enhancements

Check out the first article in the series on T-SQL Enhancements added to my web site. The article explains why such an enhancement is added to Yukon, its usage with examples and code snippets.