· Windows DNA was a programming model or blueprint that companies could use when designing n-tier distributed component-based application for the windows platform.
· Shadow Copy
This is a feature of CLR. When you update a component of ASP .Net and overwrite the old version of the component by the new one into the bin directory or in GAC, ASP .Net detected the changes and automatically loads the new component and use them to process all new web requests not currently executing, while as the same time keeping the older versions of the components loaded until previously active requests are completed.
· The .Net code you write today will also work under 64-bit versions of windows without change.
· The CLR is a runtime for all .Net languages. It is responsible for executing and managing all code written in any language.
· Code Verification is a process that ensures all code is safe to run prior to execution.
· The code produced for an application designed to run under the CLR is called managed code -self-describing code that makes use of and requires the CLR to be present. For managed code, the CLR will: always locate the metadata associated with a method at any point in time, walk the stack, handle exceptions, store and retrieve security information, manages memory and garbage collects.
· Namespaces have two key functions:
1) They logically group related types.
2) They make name collision less likely.
· We can use/declare any native CLR data types in any language, Even though that language does not support that type (does not have a mapping name for the type).
Value types in the CLR are defined as types that derive from System.ValueType. Value types are not instantiated using New (unless you have a parameterized constructor), and go out of scope when the function they are defined within returns.
· In case of boxing/un-boxing the value contained in the type and the created reference types are not associated in any way. If you change the original value type, the reference type is not affected. Boxing (Object = Value Type) occurs implicitly by the compiler/CLR, but you have to un-box (Value Type = Object) explicitly. In .Net structures are always value types.
· MSCoreLib.Dll is the mail CLR system assembly, which contains the core classes for the built-in CLR types, etc.
· Attributes are a feature of CLR compilers that enables you to annotate types with additional metadata. The CLR or other tools can than use this metadata for different purpose, such as containing documentation, information about COM+ service configuration, and so on.
· All windows applications run inside a process. Processes own many resources and threads execute code loaded into a process. If one application runs in its own process and we have multiple applications of same type (i.e. large number of web sites running on IIS) running in their own processes, they consume lots of resources. If we have multiple application are running on same process, although we can save much resources, but when an application crashes it can destroy entire process and all other applications. Application Domains in .Net have same benefits as a process, but multiple application domains can run within the same process. Application domains can be implemented safely within the same process, because the code verification feature of the CLR ensures that the code is safe to run. All the code execution in the application domain is managed by CLR, so the crashing of an application is not typically possible, and when it happens it does not affect the other applications running on other application domains.
· The concept of locating and consuming programmatic functions over the Internet is called web services. Web services are based on an application of XML called SOAP. SOAP defines a standardized format for enveloping the XML payloads exchanged between two entities over standard protocols such as HTTP. The consumers of a web service are completely shielded from any implementation details about the platform exposing the web service - they simply send and receive XML over HTTP. This means that any web service on a windows platform can be consumed by any other platform, such as UNIX.
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