What are the main components of WCF?

The main components of WCF are

1. Service class
2. Hosting environment
3. End point

What was the code name for WCF?

The code name of WCF was Indigo .

WCF is a unification of .NET framework communication technologies which unites the following technologies:-

NET remoting
MSMQ
Web services
COM+

What is three major points in WCF?

We Should remember ABC.

Address --- Specifies the location of the service which will be like http://Myserver/MyService.Clients will use this location to communicate with our service.

Binding --- Specifies how the two paries will communicate in term of transport and encoding and protocols

Contract --- Specifies the interface between client and the server.It's a simple interface with some attribute.

What are the various ways of hosting a WCF service?

Self hosting the service in his own application domain. This we have already covered in the first section. The service comes in to existence when you create the object of ServiceHost class and the service closes when you call the Close of the ServiceHost class.
Host in application domain or process provided by IIS Server.
Host in Application domain and process provided by WAS (Windows Activation Service) Server.

There are three major ways to host a WCF service:-
1. Self hosting the service in his own application domain. This we have already covered
in the first section. The service comes in to existence when you create the object of
ServiceHost class and the service closes when you call the Close of the ServiceHost
class.
2. Host in application domain or process provided by IIS Server.
3. Host in Application domain and process provided by WAS (Windows Activation
Service) Server.

Difference between WCF and Web services?

Web Services

1.It Can be accessed only over HTTP
2.It works in stateless environment

WCF

WCF is flexible because its services can be hosted in different types of applications. The following lists several common scenarios for hosting WCF services:
IIS
WAS
Self-hosting
Managed Windows Service



Web services can only be invoked by HTTP (traditional webservice with .asmx). While WCF Service or a WCF component can be invoked by any protocol (like http, tcp etc.) and any transport type.

Second web services are not flexible. However, WCF Services are flexible. If you make a new version of the service then you need to just expose a new end. Therefore, services are agile and which is a very practical approach looking at the current business trends.

We develop WCF as contracts, interface, operations, and data contracts. As the developer we are more focused on the business logic services and need not worry about channel stack. WCF is a unified programming API for any kind of services so we create the service and use configuration information to set up the communication mechanism like HTTP/TCP/MSMQ etc

What is WCF?

Windows Communication Foundation (WCF) is an SDK for developing and deploying services on Windows. WCF provides a runtime environment for services, enabling you to expose CLR types as services, and to consume other services as CLR types.

WCF is part of .NET 3.0 and requires .NET 2.0, so it can only run on systems that support it.

What is REST ?

REST stands for Representational State Transfer. (It is sometimes spelled "ReST".) It relies on a stateless, client-server, cacheable communications protocol -- and in virtually all cases, the HTTP protocol is used.

REST is an architecture style for designing networked applications. The idea is that, rather than using complex mechanisms such as CORBA, RPC or SOAP to connect between machines, simple HTTP is used to make calls between machines.

* In many ways, the World Wide Web itself, based on HTTP, can be viewed as a REST-based architecture.

RESTful applications use HTTP requests to post data (create and/or update), read data (e.g., make queries), and delete data. Thus, REST uses HTTP for all four CRUD (Create/Read/Update/Delete) operations.

REST is a lightweight alternative to mechanisms like RPC (Remote Procedure Calls) and Web Services (SOAP, WSDL, et al.). Later, we will see how much more simple REST is.

* Despite being simple, REST is fully-featured; there's basically nothing you can do in Web Services that can't be done with a RESTful architecture.

REST is not a "standard". There will never be a W3C recommendataion for REST, for example. And while there are REST programming frameworks, working with REST is so simple that you can often "roll your own" with standard library features in languages like Perl, Java, or C#.

HTTP POST Requests

static string HttpPost(string url,
string[] paramName, string[] paramVal)
{
HttpWebRequest req = WebRequest.Create(new Uri(url))
as HttpWebRequest;
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";

// Build a string with all the params, properly encoded.
// We assume that the arrays paramName and paramVal are
// of equal length:
StringBuilder params = new StringBuilder();
for (int i = 0; i < paramName.Length; i++) {
params.append(paramName[i]);
params.append("=");
params.append(HttpUtility.UrlEncode(paramVal[i]));
params.append("&");
}

// Encode the parameters as form data:
byte[] formData =
UTF8Encoding.UTF8.GetBytes(params.toString());
req.contentLength = formData.Length;

// Send the request:
using (Stream post = req.GetRequestStream())
{
post.Write(formData, 0, formData.Length);
}

// Pick up the response:
string result = null;
using (HttpWebResponse resp = req.GetResponse()
as HttpWebResponse)
{
StreamReader reader =
new StreamReader(resp.GetResponseStream());
result = reader.ReadToEnd();
}

return result;
}

HttpWebRequest and HttpWebResponse :

static string HttpGet(string url) {
HttpWebRequest req = WebRequest.Create(url)
as HttpWebRequest;
string result = null;
using (HttpWebResponse resp = req.GetResponse()
as HttpWebResponse)
{
StreamReader reader =
new StreamReader(resp.GetResponseStream());
result = reader.ReadToEnd();
}
return result;
}

LINQ : Where

public void Linq1()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

var lowNums =
from n in numbers
where n < 5
select n;

Console.WriteLine("Numbers < 5:");
foreach (var x in lowNums)
{
Console.WriteLine(x);
}
}

Order by Array Using LINQ :

public void Linq28()
{
string[] words = { "cherry", "apple", "blueberry" };

var sortedWords =
from w in words
orderby w
select w;

Console.WriteLine("The sorted list of words:");
foreach (var w in sortedWords)
{
Console.WriteLine(w);
}
}

Result

The sorted list of words:
apple
blueberry
cherry

LINQ :

Language Integrated Query (LINQ, pronounced "link") is a Microsoft .NET Framework component that adds native data querying capabilities to .NET languages.

Microsoft LINQ defines a set of method names (called standard query operators, or, more recently, standard sequencing operators[citation needed]), along with translation rules from so-called query expressions to expressions using these method names, lambda expressions and anonymous types. These can, for example, be used to project and filter data in arrays, enumerable classes, XML (XLINQ), relational database, and third party data sources. Other uses, which utilize query expressions as a general framework for readably composing arbitrary computations, include the construction of event handlers[1] or monadic parsers.[2]

Many of the concepts that LINQ has introduced were originally tested in Microsoft's Cω research project. LINQ was released as a part of .NET Framework 3.5 on November 19, 2007.

Example :

public void Linq102()

{

string[] categories = new string[]{

"Beverages",

"Condiments",

"Vegetables",

"Dairy Products",

"Seafood" };



List products = GetProductList();



var q =

from c in categories

join p in products on c equals p.Category

select new { Category = c, p.ProductName };



foreach (var v in q)

{

Console.WriteLine(v.ProductName + ": " + v.Category);

}

}

Please Refer this link :click here