Windows Communication Foundation in C#

Draw QR Code in C# Windows Communication Foundation

13 . . Examine the web .config file . ASP .NET 4 simplifies WCF Web Service configuration considerably . Earlier versions of ASP .NET (for example, version 3 .5) require you to add information about the endpoints manually . You can still tweak the bindings and add service behaviors (for example, to manage security for the service) . In this example, the default provided by Visual Studio works just fine . That is how you build a WCF service hosted through ASP .NET that can be called from anywhere in the world (where Internet service is available, that is) . In many ways, it is very similar to writing a classic ASP .NET Web service . However, because this service runs in ASP .NET side-by-side mode, there s no such thing as a current HttpContext (as is available in typical ASP .NET applications) . In many cases, this might not be necessary . You can get to many of the critical ASP .NET run-time services (for example, the cache) through the HttpRuntime object . If you need full ASP .NET support (such as for session state if the WCF service you write depends on session data), WCF supports ASP .NET Compatibility mode .

A WCF service is useless without any clients to employ it . This section illustrates how to build a client application that consumes the Quotes service . Here, you can see how Visual Studio makes it very easy to create a reference to a service . You see how to make WCF service calls both synchronously and asynchronously .

. 1 . . Start Visual Studio 2010 . Open the WCFQuotesService solution and add a new Console Application project named ConsumeQuotesService to it . The following graphic illustrates adding the Console Application project to the solution:

2 . . Create a reference to the WCFQuotesService application by right-clicking the ConsumeQuotesService Project tree node in Solution Explorer and clicking Add Service Reference . In the Add Service Reference dialog box, click the Discover button . Select the Service .svc file from this project and expand its associated tree node . After a minute, the dialog box displays the service contracts that are available through the service . Expand the Services tree in the left pane to make sure you see the IQuotesService contract . Notice the namespace given by the dialog box: ServiceReference1 . Do not click OK yet . The following graphic shows adding the service reference:

. .

3 . . Click the Advanced button . Select the Generate Asynchronous Operations option so that Visual Studio generates the asynchronous versions of the proxy methods . 4 . . Click the OK button to add the service reference . Visual Studio produces a new directory named ServiceReferences in the ConsumeQuotesService project directory . Visual Studio generates information about the service in the form of XML files, XSD files, and a WSDL file (among others) . You also get source code for a proxy class that will call the service on your behalf (by default, the proxy lands in a file named Reference .cs) . 5 . . Try calling the GetAQuote operation . Calling the proxy methods generated for the WCF service calls can be a bit verbose from time to time, but they are effective and it s much better than setting everything up manually by yourself . First, create an instance of the QuotesServiceClient, available from the ServiceReference you just created . Create an instance of the ServiceReference1.Quote structure to receive the results of calling GetAQuote . Call GetAQuote from the QuotesServiceClient, and print the result on the console .

using System; using System.Collections.Generic;