txtName.ReadOnly = true;
btnAdd.Enabled = false;
Friday, March 25, 2011
Wednesday, March 23, 2011
Crete Virtual Directoty automatically when you run VS project
In case you want to create virtual directoty of the project when you click the solution of the project.Follow these steps
1) Right click the .csproj file of the project and open with notepad. Donot open it with the VS or any other editor otherwise you won;t get the screen.
2) At the last of the file you would seetag. which needs to be updated.
3) By Default it would be like this.
ProjectExtensions
VisualStudio
FlavorProperties GUID="{349c5851-65df-11da-9384-00065b846f21}"
WebProjectProperties
UseIIS false UseIIS
true
6748
/
True
False
False
4) Change it to like like as per your requirement and the VD will be created for you when you run this project.
True
False
6748
/
http://localhost/TicklerCUW
True
http://localhost/TicklerCUW
True
False
False
1) Right click the .csproj file of the project and open with notepad. Donot open it with the VS or any other editor otherwise you won;t get the screen.
2) At the last of the file you would see
3) By Default it would be like this.
ProjectExtensions
VisualStudio
FlavorProperties GUID="{349c5851-65df-11da-9384-00065b846f21}"
WebProjectProperties
UseIIS false UseIIS
4) Change it to like like as per your requirement and the VD will be created for you when you run this project.
Thursday, February 17, 2011
What is a Class for Button
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in System.Web.dll)
Assembly: System.Web (in System.Web.dll)
Tuesday, February 1, 2011
Sql Joins
The SQL JOIN clause is used whenever we have to select data from 2 or more tables.
To be able to use SQL JOIN clause to extract data from 2 (or more) tables, we need a relationship between certain columns in these tables.
We are going to illustrate our SQL JOIN example with the following 2 tables:
Customers:
CustomerID FirstName LastName Email DOB Phone
1 John Smith John.Smith@yahoo.com 2/4/1968 626 222-2222
2 Steven Goldfish goldfish@fishhere.net 4/4/1974 323 455-4545
3 Paula Brown pb@herowndomain.org 5/24/1978 416 323-3232
4 James Smith jim@supergig.co.uk 20/10/1980 416 323-8888
Sales:
CustomerID Date SaleAmount
2 5/6/2004 $100.22
1 5/7/2004 $99.95
3 5/7/2004 $122.95
3 5/13/2004 $100.00
4 5/22/2004 $555.55
As you can see those 2 tables have common field called CustomerID and thanks to that we can extract information from both tables by matching their CustomerID columns.
Consider the following SQL statement:
SELECT Customers.FirstName, Customers.LastName, SUM(Sales.SaleAmount) AS SalesPerCustomer
FROM Customers, Sales
WHERE Customers.CustomerID = Sales.CustomerID
GROUP BY Customers.FirstName, Customers.LastName
The SQL expression above will select all distinct customers (their first and last names) and the total respective amount of dollars they have spent.
The SQL JOIN condition has been specified after the SQL WHERE clause and says that the 2 tables have to be matched by their respective CustomerID columns.
Here is the result of this SQL statement:
FirstName LastName SalesPerCustomers
John Smith $99.95
Steven Goldfish $100.22
Paula Brown $222.95
James Smith $555.55
The SQL statement above can be re-written using the SQL JOIN clause like this:
SELECT Customers.FirstName, Customers.LastName, SUM(Sales.SaleAmount) AS SalesPerCustomer
FROM Customers JOIN Sales
ON Customers.CustomerID = Sales.CustomerID
GROUP BY Customers.FirstName, Customers.LastName
There are 2 types of SQL JOINS – INNER JOINS and OUTER JOINS. If you don't put INNER or OUTER keywords in front of the SQL JOIN keyword, then INNER JOIN is used. In short "INNER JOIN" = "JOIN" (note that different databases have different syntax for their JOIN clauses).
The INNER JOIN will select all rows from both tables as long as there is a match between the columns we are matching on. In case we have a customer in the Customers table, which still hasn't made any orders (there are no entries for this customer in the Sales table), this customer will not be listed in the result of our SQL query above.
If the Sales table has the following rows:
CustomerID Date SaleAmount
2 5/6/2004 $100.22
1 5/6/2004 $99.95
And we use the same SQL JOIN statement from above:
SELECT Customers.FirstName, Customers.LastName, SUM(Sales.SaleAmount) AS SalesPerCustomer
FROM Customers JOIN Sales
ON Customers.CustomerID = Sales.CustomerID
GROUP BY Customers.FirstName, Customers.LastName
We'll get the following result:
FirstName LastName SalesPerCustomers
John Smith $99.95
Steven Goldfish $100.22
Even though Paula and James are listed as customers in the Customers table they won't be displayed because they haven't purchased anything yet.
But what if you want to display all the customers and their sales, no matter if they have ordered something or not? We’ll do that with the help of SQL OUTER JOIN clause.
The second type of SQL JOIN is called SQL OUTER JOIN and it has 2 sub-types called LEFT OUTER JOIN and RIGHT OUTER JOIN.
The LEFT OUTER JOIN or simply LEFT JOIN (you can omit the OUTER keyword in most databases), selects all the rows from the first table listed after the FROM clause, no matter if they have matches in the second table.
If we slightly modify our last SQL statement to:
SELECT Customers.FirstName, Customers.LastName, SUM(Sales.SaleAmount) AS SalesPerCustomer
FROM Customers LEFT JOIN Sales
ON Customers.CustomerID = Sales.CustomerID
GROUP BY Customers.FirstName, Customers.LastName
and the Sales table still has the following rows:
CustomerID Date SaleAmount
2 5/6/2004 $100.22
1 5/6/2004 $99.95
The result will be the following:
FirstName LastName SalesPerCustomers
John Smith $99.95
Steven Goldfish $100.22
Paula Brown NULL
James Smith NULL
As you can see we have selected everything from the Customers (first table). For all rows from Customers, which don’t have a match in the Sales (second table), the SalesPerCustomer column has amount NULL (NULL means a column contains nothing).
The RIGHT OUTER JOIN or just RIGHT JOIN behaves exactly as SQL LEFT JOIN, except that it returns all rows from the second table (the right table in our SQL JOIN statement).
self join
SELECT t1.empname [Employee], t2.empname [Manager]FROM emp t1, emp t2WHERE t1.mgrid = t2.empid
To be able to use SQL JOIN clause to extract data from 2 (or more) tables, we need a relationship between certain columns in these tables.
We are going to illustrate our SQL JOIN example with the following 2 tables:
Customers:
CustomerID FirstName LastName Email DOB Phone
1 John Smith John.Smith@yahoo.com 2/4/1968 626 222-2222
2 Steven Goldfish goldfish@fishhere.net 4/4/1974 323 455-4545
3 Paula Brown pb@herowndomain.org 5/24/1978 416 323-3232
4 James Smith jim@supergig.co.uk 20/10/1980 416 323-8888
Sales:
CustomerID Date SaleAmount
2 5/6/2004 $100.22
1 5/7/2004 $99.95
3 5/7/2004 $122.95
3 5/13/2004 $100.00
4 5/22/2004 $555.55
As you can see those 2 tables have common field called CustomerID and thanks to that we can extract information from both tables by matching their CustomerID columns.
Consider the following SQL statement:
SELECT Customers.FirstName, Customers.LastName, SUM(Sales.SaleAmount) AS SalesPerCustomer
FROM Customers, Sales
WHERE Customers.CustomerID = Sales.CustomerID
GROUP BY Customers.FirstName, Customers.LastName
The SQL expression above will select all distinct customers (their first and last names) and the total respective amount of dollars they have spent.
The SQL JOIN condition has been specified after the SQL WHERE clause and says that the 2 tables have to be matched by their respective CustomerID columns.
Here is the result of this SQL statement:
FirstName LastName SalesPerCustomers
John Smith $99.95
Steven Goldfish $100.22
Paula Brown $222.95
James Smith $555.55
The SQL statement above can be re-written using the SQL JOIN clause like this:
SELECT Customers.FirstName, Customers.LastName, SUM(Sales.SaleAmount) AS SalesPerCustomer
FROM Customers JOIN Sales
ON Customers.CustomerID = Sales.CustomerID
GROUP BY Customers.FirstName, Customers.LastName
There are 2 types of SQL JOINS – INNER JOINS and OUTER JOINS. If you don't put INNER or OUTER keywords in front of the SQL JOIN keyword, then INNER JOIN is used. In short "INNER JOIN" = "JOIN" (note that different databases have different syntax for their JOIN clauses).
The INNER JOIN will select all rows from both tables as long as there is a match between the columns we are matching on. In case we have a customer in the Customers table, which still hasn't made any orders (there are no entries for this customer in the Sales table), this customer will not be listed in the result of our SQL query above.
If the Sales table has the following rows:
CustomerID Date SaleAmount
2 5/6/2004 $100.22
1 5/6/2004 $99.95
And we use the same SQL JOIN statement from above:
SELECT Customers.FirstName, Customers.LastName, SUM(Sales.SaleAmount) AS SalesPerCustomer
FROM Customers JOIN Sales
ON Customers.CustomerID = Sales.CustomerID
GROUP BY Customers.FirstName, Customers.LastName
We'll get the following result:
FirstName LastName SalesPerCustomers
John Smith $99.95
Steven Goldfish $100.22
Even though Paula and James are listed as customers in the Customers table they won't be displayed because they haven't purchased anything yet.
But what if you want to display all the customers and their sales, no matter if they have ordered something or not? We’ll do that with the help of SQL OUTER JOIN clause.
The second type of SQL JOIN is called SQL OUTER JOIN and it has 2 sub-types called LEFT OUTER JOIN and RIGHT OUTER JOIN.
The LEFT OUTER JOIN or simply LEFT JOIN (you can omit the OUTER keyword in most databases), selects all the rows from the first table listed after the FROM clause, no matter if they have matches in the second table.
If we slightly modify our last SQL statement to:
SELECT Customers.FirstName, Customers.LastName, SUM(Sales.SaleAmount) AS SalesPerCustomer
FROM Customers LEFT JOIN Sales
ON Customers.CustomerID = Sales.CustomerID
GROUP BY Customers.FirstName, Customers.LastName
and the Sales table still has the following rows:
CustomerID Date SaleAmount
2 5/6/2004 $100.22
1 5/6/2004 $99.95
The result will be the following:
FirstName LastName SalesPerCustomers
John Smith $99.95
Steven Goldfish $100.22
Paula Brown NULL
James Smith NULL
As you can see we have selected everything from the Customers (first table). For all rows from Customers, which don’t have a match in the Sales (second table), the SalesPerCustomer column has amount NULL (NULL means a column contains nothing).
The RIGHT OUTER JOIN or just RIGHT JOIN behaves exactly as SQL LEFT JOIN, except that it returns all rows from the second table (the right table in our SQL JOIN statement).
self join
SELECT t1.empname [Employee], t2.empname [Manager]FROM emp t1, emp t2WHERE t1.mgrid = t2.empid
Tuesday, January 11, 2011
Windows Communication Foundation.
What Is Windows Communication Foundation
WCF is a framework for building service-oriented applications. Using WCF, you can send data as asynchronous messages from one service endpoint to another. A service endpoint can be part of a continuously available service hosted by IIS, or it can be a service hosted in an application. An endpoint can be a client of a service that requests data from a service endpoint. The messages can be as simple as a single character or word sent as XML, or as complex as a stream of binary data. A few sample scenarios include:
Features of WCF
Service Orientation
One consequence of using WS standards is that WCF enables you to create service oriented applications. Service-oriented architecture (SOA) is the reliance on Web services to send and receive data. The services have the general advantage of being loosely-coupled instead of hard-coded from one application to another. A loosely-coupled relationship implies that any client created on any platform can connect to any service as long as the essential contracts are met.
Interoperability
WCF implements modern industry standards for Web service interoperability
Multiple Message Patterns
Messages are exchanged in one of several patterns. The most common pattern is the request/reply pattern, where one endpoint requests data from a second endpoint. The second endpoint replies. There are other patterns such as a one-way message in which a single endpoint sends a message without any expectation of a reply. A more complex pattern is the duplex exchange pattern where two endpoints establish a connection and send data back and forth, similar to an instant messaging program
Data Contracts
Because WCF is built using the .NET Framework, it also includes code-friendly methods of supplying the contracts you want to enforce. One of the universal types of contracts is the data contract. In essence, as you code your service using Visual C# or Visual Basic, the easiest way to handle data is by creating classes that represent a data entity with properties that belong to the data entity. WCF includes a comprehensive system for working with data in this easy manner. Once you have created the classes that represent data, your service automatically generates the metadata that allows clients to comply with the data types you have designed
Security
Messages can be encrypted to protect privacy and you can require users to authenticate themselves before being allowed to receive messages. Security can be implemented using well-known standards such as SSL or WS-SecureConversation
Multiple Transports and Encodings
Messages can be sent on any of several built-in transport protocols and encodings. The most common protocol and encoding is to send text encoded SOAP messages using is the HyperText Transfer Protocol (HTTP) for use on the World Wide Web. Alternatively, WCF allows you to send messages over TCP, named pipes, or MSMQ. These messages can be encoded as text or using an optimized binary format. Binary data can be sent efficiently using the MTOM standard. If none of the provided transports or encodings suit your needs you can create your own custom transport or encoding
Reliable and Queued Messages
WCF supports reliable message exchange using reliable sessions implemented over WS-Reliable Messaging and using MSMQ
Durable Messages
A durable message is one that is never lost due to a disruption in the communication. The messages in a durable message pattern are always saved to a database. If a disruption occurs, the database allows you to resume the message exchange when the connection is restored. You can also create a durable message using the Windows Workflow Foundation (WF).
Transactions
WCF also supports transactions using one of three transaction models: WS-AtomicTtransactions, the APIs in the System.Transactions namespace, and Microsoft Distributed Transaction Coordinator
Extensibility
The WCF architecture has a number of extensibility points. If extra capability is required, there are a number of entry points that allow you to customize the behavior of a service
WCF Terms
message A self-contained unit of data that can consist of several parts, including a body and headers.
service A construct that exposes one or more endpoints, with each endpoint exposing one or more service operations.
endpoint A construct at which messages are sent or received (or both). It comprises a location (an address) that defines where messages can be sent, a specification of the communication mechanism (a binding) that described how messages should be sent, and a definition for a set of messages that can be sent or received (or both) at that location (a service contract) that describes what message can be sent.
A WCF service is exposed to the world as a collection of endpoints.
application endpoint
An endpoint exposed by the application and that corresponds to a service contract implemented by the application
infrastructure endpoint An endpoint that is exposed by the infrastructure to facilitate functionality that is needed or provided by the service that does not relate to a service contract. For example, a service might have an infrastructure endpoint that provides metadata information
address Specifies the location where messages are received. It is specified as a Uniform Resource Identifier (URI). The URI schema part names the transport mechanism to use to reach the address, such as HTTP and TCP. The hierarchical part of the URI contains a unique location whose format is dependent on the transport mechanism.
The endpoint address enables you to create unique endpoint addresses for each endpoint in a service or, under certain conditions, to share an address across endpoints. The following example shows an address using the HTTPS protocol with a non-default port:
HTTPS://cohowinery:8005/ServiceModelSamples/CalculatorService
bindingDefines how an endpoint communicates to the world. It is constructed of a set of components called binding elements that "stack" one on top of the other to create the communication infrastructure. At the very least, a binding defines the transport (such as HTTP or TCP) and the encoding being used (such as text or binary). A binding can contain binding elements that specify details like the security mechanisms used to secure messages, or the message pattern used by an endpoint. For more information, see Configuring Services.
binding elementRepresents a particular piece of the binding, such as a transport, an encoding, an implementation of an infrastructure-level protocol (such as WS-ReliableMessaging), or any other component of the communication stack.
behaviorsA component that controls various run-time aspects of a service, an endpoint, a particular operation, or a client. Behaviors are grouped according to scope: common behaviors affect all endpoints globally, service behaviors affect only service-related aspects, endpoint behaviors affect only endpoint-related properties, and operation-level behaviors affect particular operations. For example, one service behavior is throttling, which specifies how a service reacts when an excess of messages threaten to overwhelm its handling capabilities. An endpoint behavior, on the other hand, controls only aspects that are relevant to endpoints, such as how and where to find a security credential.
system-provided bindingsWCF includes a number of system-provided bindings. These are collections of binding elements that are optimized for specific scenarios. For example, the WSHttpBinding is designed for interoperability with services that implement various WS-* specifications. These predefined bindings save time by presenting only those options that can be correctly applied to the specific scenario. If a predefined binding does not meet your requirements, you can create your own custom binding.
configuration versus codingControl of an application can be done either through coding, through configuration, or through a combination of both. Configuration has the advantage of allowing someone other than the developer (for example, a network administrator) to set client and service parameters after the code is written and without having to recompile. Configuration not only enables you to set values like endpoint addresses, but also allows further control by enabling you to add endpoints, bindings, and behaviors. Coding allows the developer to retain strict control over all components of the service or client, and any settings done through the configuration can be inspected and if needed overridden by the code.
service operationA procedure defined in a service's code that implements the functionality for an operation. This operation is exposed to clients as methods on a WCF client. The method can return a value, and can take an optional number of arguments, or take no arguments, and return no response. For example, an operation that functions as a simple "Hello" can be used as a notification of a client's presence and to begin a series of operations.
service contractTies together multiple related operations into a single functional unit. The contract can define service-level settings, such as the namespace of the service, a corresponding callback contract, and other such settings. In most cases, the contract is defined by creating an interface in the programming language of your choice and applying the ServiceContractAttribute attribute to the interface. The actual service code results by implementing the interface.
operation contractAn operation contract defines the parameters and return type of an operation. When creating an interface that defines the service contract, you signify an operation contract by applying the OperationContractAttribute attribute to each method definition that is part of the contract. The operations can be modeled as taking a single message and returning a single message, or as taking a set of types and returning a type. In the latter case, the system will determine the format for the messages that need to be exchanged for that operation.
message contractDescribes the format of a message. For example, it declares whether message elements should go in headers versus the body, what level of security should be applied to what elements of the message, and so on.
fault contractCan be associated with a service operation to denote errors that can be returned to the caller. An operation can have zero or more faults associated with it. These errors are SOAP faults that are modeled as exceptions in the programming model.
data contractThe descriptions in metadata of the data types that a service uses. This enables others to interoperate with the service. The data types can be used in any part of a message, for example, as parameters or return types. If the service is using only simple types, there is no need to explicitly use data contracts.
hostingA service must be hosted in some process. A host is an application that controls the lifetime of the service. Services can be self-hosted or managed by an existing hosting process.
self-hosted serviceA service that runs within a process application that the developer created. The developer controls its lifetime, sets the properties of the service, opens the service (which sets it into a listening mode), and closes the service.
hosting processAn application that is designed to host services. These include Internet Information Services (IIS), Windows Activation Services (WAS), and Windows Services. In these hosted scenarios, the host controls the lifetime of the service. For example, using IIS you can set up a virtual directory that contains the service assembly and configuration file. When a message is received, IIS starts the service and controls its lifetime.
instancingA service has an instancing model. There are three instancing models: "single," in which a single CLR object services all the clients; "per call," in which a new CLR object is created to handle each client call; and "per session," in which a set of CLR objects is created, one for each separate session. The choice of an instancing model depends on the application requirements and the expected usage pattern of the service.
client applicationA program that exchanges messages with one or more endpoints. The client application begins by creating an instance of a WCF client and calling methods of the WCF client. It is important to note that a single application can be both a client and a service.
channelA concrete implementation of a binding element. The binding represents the configuration, and the channel is the implementation associated with that configuration. Therefore, there is a channel associated with each binding element. Channels stack on top of each other to create the concrete implementation of the binding: the channel stack.
WCF clientA client-application construct that exposes the service operations as methods (in the .NET Framework programming language of your choice, such as Visual Basic or Visual C#). Any application can host a WCF client, including an application that hosts a service. Therefore, it is possible to create a service that includes WCF clients of other services.
A WCF client can be automatically generated by using the ServiceModel Metadata Utility Tool (Svcutil.exe) and pointing it at a running service that publishes metadata.
metadata In a service, describes the characteristics of the service that an external entity needs to understand to communicate with the service. Metadata can be consumed by the ServiceModel Metadata Utility Tool (Svcutil.exe) to generate a WCF client and accompanying configuration that a client application can use to interact with the service.
The metadata exposed by the service includes XML schema documents, which define the data contract of the service, and WSDL documents, which describe the methods of the service.
When enabled, metadata for the service is automatically generated by WCF by inspecting the service and its endpoints. To publish metadata from a service, you must explicitly enable the metadata behavior.
securityIn WCF, includes confidentiality (encryption of messages to prevent eavesdropping), integrity (the means for detection of tampering with the message), authentication (the means for validation of servers and clients), and authorization (the control of access to resources). These functions are provided by either leveraging existing security mechanisms, such as TLS over HTTP (also known as HTTPS), or by implementing one or more of the various WS-* security specifications.
transport security modeSpecifies that confidentiality, integrity, and authentication are provided by the transport layer mechanisms (such as HTTPS). When using a transport like HTTPS, this mode has the advantage of being efficient in its performance, and well understood because of its prevalence on the Internet. The disadvantage is that this kind of security is applied separately on each hop in the communication path, making the communication susceptible to a "man in the middle" attack.
message security modeSpecifies that security is provided by implementing one or more of the security specifications, such as the specification named Web Services Security: SOAP Message Security. Each message contains the necessary mechanisms to provide security during its transit, and to enable the receivers to detect tampering and to decrypt the messages. In this sense, the security is encapsulated within every message, providing end-to-end security across multiple hops. Because security information becomes part of the message, it is also possible to include multiple kinds of credentials with the message (these are referred to as claims). This approach also has the advantage of enabling the message to travel securely over any transport, including multiple transports between its origin and destination. The disadvantage of this approach is the complexity of the cryptographic mechanisms employed, resulting in performance implications.
transport with message credential security modeSpecifies the use of the transport layer to provide confidentiality, authentication, and integrity of the messages, while each of the messages can contain multiple credentials (claims) required by the receivers of the message.
WCF is a framework for building service-oriented applications. Using WCF, you can send data as asynchronous messages from one service endpoint to another. A service endpoint can be part of a continuously available service hosted by IIS, or it can be a service hosted in an application. An endpoint can be a client of a service that requests data from a service endpoint. The messages can be as simple as a single character or word sent as XML, or as complex as a stream of binary data. A few sample scenarios include:
Features of WCF
Service Orientation
One consequence of using WS standards is that WCF enables you to create service oriented applications. Service-oriented architecture (SOA) is the reliance on Web services to send and receive data. The services have the general advantage of being loosely-coupled instead of hard-coded from one application to another. A loosely-coupled relationship implies that any client created on any platform can connect to any service as long as the essential contracts are met.
Interoperability
WCF implements modern industry standards for Web service interoperability
Multiple Message Patterns
Messages are exchanged in one of several patterns. The most common pattern is the request/reply pattern, where one endpoint requests data from a second endpoint. The second endpoint replies. There are other patterns such as a one-way message in which a single endpoint sends a message without any expectation of a reply. A more complex pattern is the duplex exchange pattern where two endpoints establish a connection and send data back and forth, similar to an instant messaging program
Data Contracts
Because WCF is built using the .NET Framework, it also includes code-friendly methods of supplying the contracts you want to enforce. One of the universal types of contracts is the data contract. In essence, as you code your service using Visual C# or Visual Basic, the easiest way to handle data is by creating classes that represent a data entity with properties that belong to the data entity. WCF includes a comprehensive system for working with data in this easy manner. Once you have created the classes that represent data, your service automatically generates the metadata that allows clients to comply with the data types you have designed
Security
Messages can be encrypted to protect privacy and you can require users to authenticate themselves before being allowed to receive messages. Security can be implemented using well-known standards such as SSL or WS-SecureConversation
Multiple Transports and Encodings
Messages can be sent on any of several built-in transport protocols and encodings. The most common protocol and encoding is to send text encoded SOAP messages using is the HyperText Transfer Protocol (HTTP) for use on the World Wide Web. Alternatively, WCF allows you to send messages over TCP, named pipes, or MSMQ. These messages can be encoded as text or using an optimized binary format. Binary data can be sent efficiently using the MTOM standard. If none of the provided transports or encodings suit your needs you can create your own custom transport or encoding
Reliable and Queued Messages
WCF supports reliable message exchange using reliable sessions implemented over WS-Reliable Messaging and using MSMQ
Durable Messages
A durable message is one that is never lost due to a disruption in the communication. The messages in a durable message pattern are always saved to a database. If a disruption occurs, the database allows you to resume the message exchange when the connection is restored. You can also create a durable message using the Windows Workflow Foundation (WF).
Transactions
WCF also supports transactions using one of three transaction models: WS-AtomicTtransactions, the APIs in the System.Transactions namespace, and Microsoft Distributed Transaction Coordinator
Extensibility
The WCF architecture has a number of extensibility points. If extra capability is required, there are a number of entry points that allow you to customize the behavior of a service
WCF Terms
message A self-contained unit of data that can consist of several parts, including a body and headers.
service A construct that exposes one or more endpoints, with each endpoint exposing one or more service operations.
endpoint A construct at which messages are sent or received (or both). It comprises a location (an address) that defines where messages can be sent, a specification of the communication mechanism (a binding) that described how messages should be sent, and a definition for a set of messages that can be sent or received (or both) at that location (a service contract) that describes what message can be sent.
A WCF service is exposed to the world as a collection of endpoints.
application endpoint
An endpoint exposed by the application and that corresponds to a service contract implemented by the application
infrastructure endpoint An endpoint that is exposed by the infrastructure to facilitate functionality that is needed or provided by the service that does not relate to a service contract. For example, a service might have an infrastructure endpoint that provides metadata information
address Specifies the location where messages are received. It is specified as a Uniform Resource Identifier (URI). The URI schema part names the transport mechanism to use to reach the address, such as HTTP and TCP. The hierarchical part of the URI contains a unique location whose format is dependent on the transport mechanism.
The endpoint address enables you to create unique endpoint addresses for each endpoint in a service or, under certain conditions, to share an address across endpoints. The following example shows an address using the HTTPS protocol with a non-default port:
HTTPS://cohowinery:8005/ServiceModelSamples/CalculatorService
bindingDefines how an endpoint communicates to the world. It is constructed of a set of components called binding elements that "stack" one on top of the other to create the communication infrastructure. At the very least, a binding defines the transport (such as HTTP or TCP) and the encoding being used (such as text or binary). A binding can contain binding elements that specify details like the security mechanisms used to secure messages, or the message pattern used by an endpoint. For more information, see Configuring Services.
binding elementRepresents a particular piece of the binding, such as a transport, an encoding, an implementation of an infrastructure-level protocol (such as WS-ReliableMessaging), or any other component of the communication stack.
behaviorsA component that controls various run-time aspects of a service, an endpoint, a particular operation, or a client. Behaviors are grouped according to scope: common behaviors affect all endpoints globally, service behaviors affect only service-related aspects, endpoint behaviors affect only endpoint-related properties, and operation-level behaviors affect particular operations. For example, one service behavior is throttling, which specifies how a service reacts when an excess of messages threaten to overwhelm its handling capabilities. An endpoint behavior, on the other hand, controls only aspects that are relevant to endpoints, such as how and where to find a security credential.
system-provided bindingsWCF includes a number of system-provided bindings. These are collections of binding elements that are optimized for specific scenarios. For example, the WSHttpBinding is designed for interoperability with services that implement various WS-* specifications. These predefined bindings save time by presenting only those options that can be correctly applied to the specific scenario. If a predefined binding does not meet your requirements, you can create your own custom binding.
configuration versus codingControl of an application can be done either through coding, through configuration, or through a combination of both. Configuration has the advantage of allowing someone other than the developer (for example, a network administrator) to set client and service parameters after the code is written and without having to recompile. Configuration not only enables you to set values like endpoint addresses, but also allows further control by enabling you to add endpoints, bindings, and behaviors. Coding allows the developer to retain strict control over all components of the service or client, and any settings done through the configuration can be inspected and if needed overridden by the code.
service operationA procedure defined in a service's code that implements the functionality for an operation. This operation is exposed to clients as methods on a WCF client. The method can return a value, and can take an optional number of arguments, or take no arguments, and return no response. For example, an operation that functions as a simple "Hello" can be used as a notification of a client's presence and to begin a series of operations.
service contractTies together multiple related operations into a single functional unit. The contract can define service-level settings, such as the namespace of the service, a corresponding callback contract, and other such settings. In most cases, the contract is defined by creating an interface in the programming language of your choice and applying the ServiceContractAttribute attribute to the interface. The actual service code results by implementing the interface.
operation contractAn operation contract defines the parameters and return type of an operation. When creating an interface that defines the service contract, you signify an operation contract by applying the OperationContractAttribute attribute to each method definition that is part of the contract. The operations can be modeled as taking a single message and returning a single message, or as taking a set of types and returning a type. In the latter case, the system will determine the format for the messages that need to be exchanged for that operation.
message contractDescribes the format of a message. For example, it declares whether message elements should go in headers versus the body, what level of security should be applied to what elements of the message, and so on.
fault contractCan be associated with a service operation to denote errors that can be returned to the caller. An operation can have zero or more faults associated with it. These errors are SOAP faults that are modeled as exceptions in the programming model.
data contractThe descriptions in metadata of the data types that a service uses. This enables others to interoperate with the service. The data types can be used in any part of a message, for example, as parameters or return types. If the service is using only simple types, there is no need to explicitly use data contracts.
hostingA service must be hosted in some process. A host is an application that controls the lifetime of the service. Services can be self-hosted or managed by an existing hosting process.
self-hosted serviceA service that runs within a process application that the developer created. The developer controls its lifetime, sets the properties of the service, opens the service (which sets it into a listening mode), and closes the service.
hosting processAn application that is designed to host services. These include Internet Information Services (IIS), Windows Activation Services (WAS), and Windows Services. In these hosted scenarios, the host controls the lifetime of the service. For example, using IIS you can set up a virtual directory that contains the service assembly and configuration file. When a message is received, IIS starts the service and controls its lifetime.
instancingA service has an instancing model. There are three instancing models: "single," in which a single CLR object services all the clients; "per call," in which a new CLR object is created to handle each client call; and "per session," in which a set of CLR objects is created, one for each separate session. The choice of an instancing model depends on the application requirements and the expected usage pattern of the service.
client applicationA program that exchanges messages with one or more endpoints. The client application begins by creating an instance of a WCF client and calling methods of the WCF client. It is important to note that a single application can be both a client and a service.
channelA concrete implementation of a binding element. The binding represents the configuration, and the channel is the implementation associated with that configuration. Therefore, there is a channel associated with each binding element. Channels stack on top of each other to create the concrete implementation of the binding: the channel stack.
WCF clientA client-application construct that exposes the service operations as methods (in the .NET Framework programming language of your choice, such as Visual Basic or Visual C#). Any application can host a WCF client, including an application that hosts a service. Therefore, it is possible to create a service that includes WCF clients of other services.
A WCF client can be automatically generated by using the ServiceModel Metadata Utility Tool (Svcutil.exe) and pointing it at a running service that publishes metadata.
metadata In a service, describes the characteristics of the service that an external entity needs to understand to communicate with the service. Metadata can be consumed by the ServiceModel Metadata Utility Tool (Svcutil.exe) to generate a WCF client and accompanying configuration that a client application can use to interact with the service.
The metadata exposed by the service includes XML schema documents, which define the data contract of the service, and WSDL documents, which describe the methods of the service.
When enabled, metadata for the service is automatically generated by WCF by inspecting the service and its endpoints. To publish metadata from a service, you must explicitly enable the metadata behavior.
securityIn WCF, includes confidentiality (encryption of messages to prevent eavesdropping), integrity (the means for detection of tampering with the message), authentication (the means for validation of servers and clients), and authorization (the control of access to resources). These functions are provided by either leveraging existing security mechanisms, such as TLS over HTTP (also known as HTTPS), or by implementing one or more of the various WS-* security specifications.
transport security modeSpecifies that confidentiality, integrity, and authentication are provided by the transport layer mechanisms (such as HTTPS). When using a transport like HTTPS, this mode has the advantage of being efficient in its performance, and well understood because of its prevalence on the Internet. The disadvantage is that this kind of security is applied separately on each hop in the communication path, making the communication susceptible to a "man in the middle" attack.
message security modeSpecifies that security is provided by implementing one or more of the security specifications, such as the specification named Web Services Security: SOAP Message Security. Each message contains the necessary mechanisms to provide security during its transit, and to enable the receivers to detect tampering and to decrypt the messages. In this sense, the security is encapsulated within every message, providing end-to-end security across multiple hops. Because security information becomes part of the message, it is also possible to include multiple kinds of credentials with the message (these are referred to as claims). This approach also has the advantage of enabling the message to travel securely over any transport, including multiple transports between its origin and destination. The disadvantage of this approach is the complexity of the cryptographic mechanisms employed, resulting in performance implications.
transport with message credential security modeSpecifies the use of the transport layer to provide confidentiality, authentication, and integrity of the messages, while each of the messages can contain multiple credentials (claims) required by the receivers of the message.
Tuesday, December 21, 2010
Find Age
To Find the age of a person there is another class avaliable in VS
C#
TimeSpan
Datetime myBirthday=DateTime.Parse("7/7/1982");
TimeSpan objTimeSpan=DateTime.Now.Subtract(myBirthDay);
C#
TimeSpan
Datetime myBirthday=DateTime.Parse("7/7/1982");
TimeSpan objTimeSpan=DateTime.Now.Subtract(myBirthDay);
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