What is boxing and unboxing explain with example?

Boxing permits any value type to be implicitly converted to type object or to any interface type implemented by value type. Boxing is a process in which object instances are created and copy values in to that instance. Unboxing is vice versa of boxing operation where the value is copied from the instance in to appropriate storage location. Below is sample code of boxing and unboxing where integer data type is converted in to object and then vice versa.
Dim x As Integer
Dim y As Object x = 10
' boxing process
y = x
' unboxing process
x = y (More...)

Converting a value type to reference type is called Boxing and Converting reference type of value type is Unboxing.

int i = 1;
object o = i; // boxing
int j = (int) o; // unboxing (More...)

It is a useful, memory-saving technique for multiprogrammed timesharing systems. A Reentrant Procedure is one in which multiple users can share a single copy of a program during the same period. Reentrancy has 2 key aspects: The program code cannot modify itself, and the local data for each user process must be stored separately. Thus, the permanent part is the code, and the temporary part is the pointer back to the calling program and local variables used by that program. Each execution instance is called activation. It executes the code in the permanent part, but has its own copy of local variables/parameters. The temporary part associated with each activation is the activation record. Generally, the activation record is kept on the stack.

Note: A reentrant procedure can be interrupted and called by an interrupting program, and still execute correctly on returning to the procedure. (More...)

Also called FIFO anomaly. Usually, on increasing the number of frames allocated to a process' virtual memory, the process execution is faster, because fewer page faults occur. Sometimes, the reverse happens, i.e., the execution time increases even when more frames are allocated to the process. This is Belady's Anomaly. This is true for certain page reference patterns. (More...)

Manifest is metadata about assemblies. Metadata is machine-readable information about a resource, or ""data about data." In .NET, metadata includes type definitions, version information, external assembly references, and other standardized information. (More...)

Life cycle of ASP.Net Web Form
Page Request >> Start >> Page Init >> Page Load >> Validation >>
PostBack Event Handling >> Page Rendering >> Page Unload
Page Request - When the page is requested ASP.Net determines
whether the page is to be parsed and compiled or a cached verion
of the page is to be sent without running the page.
Start - Page propertied REQUEST and RESPONSE are SET, if the
page is pastback request then the IsPostBack property is SET and
in addition to this UICulture property is also SET.
Page Initilization - In this the UniqueID of each property is SET.
If the request was postback the data is not yet loaded from the
viewstate.
Page Load - If it was a postback request then the data gets loaded
in the control from the ViewState and control property are set.
Validation - If any control validation present, they are performed
and IsValid property is SET for each control.
PostBack Event Handling - If it was a postback request then any
event handlers are called.
Page Rendering - Before this the viewstate is saved from the page
and RENDER method of each page is called.
Page Unload - Page is fully rendered and sent to the client(Browser)
and is discarded. Page property RESPONSE and REQUEST are unloaded. (More...)

Manifest is metadata about assemblies. Metadata is machine-readable information about a resource, or ""data about data." In .NET, metadata includes type definitions, version information, external assembly references, and other standardized information.

Manifest: Manifest describes assembly itself. Assembly Name, version number, culture, strong name, list of all files, Type references, and referenced assemblies.

Metadata: Metadata describes contents in an assembly classes, interfaces, enums, structs, etc., and their containing namespaces, the name of each type, its visibility/scope, its base class, the nterfaces it implemented, its methods and their scope, and each method's parameters, type's properties, and so on.

Shashi Ray (More...)

Virtual functions implement the concept of polymorphism are the same as in C#, except that you use the override keyword with the virtual function implementaion in the child class.

The parent class uses the same virtual keyword. Every class that overrides the virtual method will use the override keyword.


class Shape{
public virtual void Draw()
{ Console.WriteLine("Shape.Draw") ; }
}
class Rectangle : Shape{
public override void Draw()
{ Console.WriteLine("Rectangle.Draw"); }
} (More...)

Readystate property holds the response of the server to the query generated from the client side. Each time the readystate property changes onreadystatechange function will be executed. Some of the values for the readystate property are as follows if the status is zero the request is not initialized, 1 the request has been set up, 2 the request has been sent, 3 the request is in process, 4 the request is complete. (More...)

Notification Services applications are based on a subscriber/subscription model.
The Key components in a Notification Services application are

Subscriber: A user or application that requests and receives the notification
Subscription: A request for information, delivery mechanism, and destination for requested notifications. For example change of a stock price.
Event: A piece of information, in which the subscriber is interested. For example as soon as a stock price has changed an event can be generated that's processed within SQLNS.
Notification: A message containing the information requested by the subscriber in the subscription.

SQLNS executes the following steps whenever it generates a new notification and sends it to registered subscribers:

.Subscribers create subscriptions with a subscription management application, such as an ASP.NET or Windows Forms front end.
.Subscription management is the only part of an SQLNS application where users or applications are actively involved in the process. You generate subscriptions using a managed assembly shipped with SQLNS.
.The Notification Application collects events, which are processed within the SQLNS application.
.SQLNS uses T-SQL statements to assign events to the subscriptions registered in the first step.
.SQLNS generates new notifications whenever it finds an assignment.
.A Formatter formats the new notification, and SQLNS delivers it through a delivery channel to the registered target device of the subscriber. (More...)