Dotnet framework difference faqs- 3

1.Difference between Namespace and Assembly S.No Namespace Assembly 1 Namespace is the logical naming Scope for a particular type is defined at decided at design time by the run time using Assembly. developer. 2 Namespace contains set of unique Assembly contains code of the form names. MSIL ( Microsoft Intermediate Language) 3 Classes available in your program Logical units are physically grouped will be logically grouped together together as assembly. under a namespace. 4 Namespace can include multiple An assembly can contain types assemblies. belonging to different namespaces. 5 Namespace doesnt have any Assembly can be classified as private classification. assembly and public assembly. Private assembly is specific to a single application but shared/public assembly contains libraries which can be used by multiple applications. 6 Namespaces have to be mentioned Assemblies need not be explicitly in Project-Properties. specified. They are automatically described in metadata and manifest files. 7 Namespaces can be nested. For Such nesting is not permissible in example: assemblies. namespace sampleApp1 { namespace SampleApp2 { class sampleClass { … } } } 8 Namespace is the one which you Creating an assembly on your own is directly specify in your code. A not as simple as you create a simple example for namespace is namespace. If you want to package the shown below: code shown as an example for the namespace sampleNamespace { namespace into an assembly, then you class sampleClass { have to follow the steps shown below: public void displayMsg() { " Generate a key file inside the same Console.WriteLine("In folder where you have placed the code sampleClass"); by typing the following statement in } the command prompt: } sn -k sampleKey.key } " Sign your code component with this

In this example, key. Assume that your code component sampleNamespace is the is named as sampleClass.cs. Now use namespace you have created and the following command: sampleClass is within the scope of csc sampleClass.cs /t:library this namespace. /a.keyfile:sampleKey.key " Place your signed assembly inside GAC using AL Utility: AL /i: sampleClass.dll " Now create a code that accesses the code in your assembly: Using System; Using sampleNamespace; public class testClass { sampleClass obj = new sampleClass(); obj.displayMsg(); } " To test if your assembly got created and to test if the above code is working, compile the above code using the following statement: csc testClass.cs /t:exe /r:<path of your assembly> " Now if you execute testClass.cs, you should get the following output: In sampleClass2.Difference between System Exception and Application Exception S.No System Exception Application Exception 1 CLR throws system exception Application throws application exception 2 System exceptions are generic in Application exceptions are not generic. nature Each application exception has its own customized meaning 3 Each system exception has a Application exceptions do not have a meaning. You can directly use meaning for themselves. You have to them or you can derive new ones explicitly derive from them and create by inheriting System.Exception your own custom exceptions specific to your application 4 Example for system exceptions Example for application exceptions include SqlException, include SharePointException, StackOverflowException CmsException

3.Difference between COM and .NET Component S.No COM Component .NET Component 1 Interface based communication Object based communication 2 Reference count will be used to Garbage Collector to manage memory manage memory 3 Binary Standard objects Type Standard objects 4 Objects are created by Objects are created by normal new coCreateInstance operator 5 Object info resides in Type library Object info resides in assembly files 6 HRESULT will be returned Exceptions will be returned COM=HRESULT will be returned4.Difference between Private Assembly and Public Assembly S.No Private Assembly Public Assembly 1 Private assembly can be used by Public assembly can be used by only one application. multiple applications. 2 Private assembly will be stored in Public assembly is stored in GAC the specific applications directory (Global Assembly Cache). or sub-directory. 3 There is no other name for private Public assembly is also termed as assembly. shared assembly. 4 Strong name is not required for Strong name has to be created for private assembly. public assembly. 5 Private assembly doesnt have any Public assembly should strictly enforce version constraint. version constraint. 6 By default, all assemblies you An example to public assembly is the create are examples of private actuate report classes which can be assembly. Only when you imported in the library and used by any associate a strong name to it and application that prefers to implement store it in GAC, it becomes a actuate reports. public assembly.And, further updates on difference between questions and answers, please visit my blog @http://onlydifferencefaqs.blogspot.in/

Dotnet framework difference faqs- 3

by Umar Ali on Aug 07, 2012

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