Advantages of WCF

1. WCF is interoperable with other services when compared to .Net Remoting where the client and service have to be .Net.
2. WCF services provide better reliability and security in compared to ASMX web services.
3. In WCF, there is no need to make much change in code for implementing the security model and changing the binding. Small changes in the configuration will make your requirements.
4. WCF has integrated logging mechanism, changing the configuration file settings will provide this functionality. In other technology developer has to write the code.

Difference between WCF and Web Service

Web service is a part of WCF. WCF offers much more flexibility and portability to develop a service when comparing to web service.

WCF Service is composed of three components:

Service Class

A WCF service class implements some service as a set of methods.

Host

A Host environment can be a Console application or a Windows Service or a Windows Forms application or IIS as in case of the normal asmx web service in .NET.

Endpoint

All communications with the WCF service will happen via the endpoints. The endpoint is composed of 3 parts (collectively called as ABC’s of endpoint) as defines below:
A for (Address)  = Where is the Web Service?
B for (Binding) = How can we talk to the Service?
C for (Contract)  = What can the service do for us?

1. Address

The endpoints specify an Address that defines where the endpoint is hosted. It’s basically url.

Eg. http://localhost/wcfService/Service.svc

2. Binding

The endpoints also define a binding that specifies how a client will communicate with the service and the address where the endpoint is hosted.

3. Contract

Contract defines which methods of the Service class will be accessible via the endpoint; each endpoint may expose a different set of methods.

Different contracts in WCF
a. Service Contract

Service contracts describe the operation that service can provide. For Eg, a Service provide to know the temperature of the city based on the zip code, this service is called as Service contract. It will be created using Service and Operational Contract attribute.

b. Data Contract

Data contract describes the custom data type which is exposed to the client. This defines the data types, which are passed to and from service. Data types like int, string are identified by the client because it is already mention in XML schema definition language document, but custom created class or data types cannot be identified by the client e.g. Employee data type. By using DataContract we can make client to be aware of Employee data type that are returning or passing parameter to the method.

c. Message Contract

Default SOAP message format is provided by the WCF runtime for communication between Client and service. If it is not meeting your requirements then we can create our own message format. This can be achieved by using Message Contract attribute.

d. Fault Contract

Suppose the service I consumed is not working in the client application. I want to know the real cause of the problem. How I can know the error? For this we are having Fault Contract. Fault Contract provides documented view for error occurred in the service to client. This helps us to easy identity, what error has occurred.

Web Service is an application that is designed to interact directly with other applications over the internet. In simple sense, Web Services are means for interacting with objects over the Internet.

• Web Service is
• Language Independent
• Protocol Independent
• Platform Independent
• It assumes stateless service architecture.

History of Web Service or How Web Service comes into existence?

As i have mention before that Web Service is nothing but means for interacting with objects over the Internet.

• Initially Object – Oriented Language comes which allow us to interact with two object within same application.
• Component Object Model (COM) which allows to interact two objects on the same computer, but in different applications.
• Distributed Component Object Model (DCOM) which allows to interact two objects on different computers, but within same local network.
• which allows two object to interact internet. That is it allows to interact between two object on different computers and even not within same local network.

Example of Web Service

• Weather Reporting: You can use Weather Reporting web service to display weather information in your personal website.
• Stock Quote: You can display latest update of Share market with Stock Quote on your web site.
• News Headline: You can display latest news update by using News Headline Web Service in your website.
• In summary you can any use any web service which is available to use. You can make your own web service and let others use it. Example you can make Free SMS Sending Service with footer with your companies advertisement, so whosoever use this service indirectly advertise your company… You can apply your ideas in N no. of ways to take advantage of it.

Web Service Communication
Web Services communicate by using standard web protocols and data formats, such as

• HTTP
• XML
• SOAP

Advantages of Web Service Communication
Web Service messages are formatted as XML, a standard way for communication between two incompatible systems. And this message is sent via HTTP, so that they can reach to any machine on the internet without being blocked by firewall.

Terms which are frequently used with web services:

What is SOAP?

SOAP is remote function calls that invokes method and execute them on Remote machine and translate the object communication into XML format. In short, SOAP are way by which method calls are translate into XML format and sent via HTTP.

What is WSDL?

WSDL stands for Web Service Description Language, a standard by which a web service can tell clients what messages it accepts and which results it will return.

• WSDL contains every details regarding using web service
• Method and Properties provided by web service
• URLs from which those method can be accessed.
• Data Types used.
• Communication Protocol used.

What is UDDI?

UDDI allows you to find web services by connecting to a directory.

What is Discovery or .Disco Files?

Discovery files are used to group common services together on a web server. Discovery files .Disco and .VsDisco are XML based files that contains link in the form of URLs to resources that provides discovery information for a web service.

.Disco File (static)

• .Disco File contains
• URL for the WSDL
• URL for the documentation
• URL to which SOAP messages should be sent.
• A static discovery file is an XML document that contains links to other resources that describe web services.

.VsDisco File (dynamic)

A dynamic discovery files are dynamic discovery document that are automatically generated by VS.Net during the development phase of a web service.

What is difference between Disco and UDDI?

Disco is Microsoft’s Standard format for discovery documents which contains information about Web Services, while UDDI is a multi-vendor standard for discovery documents which contains information about Web Services.

What is Web Service Discovery Tool (disco.exe)?

The Web Services Discovery Tool (disco.exe) can retrieve discovery information from a server that exposes a web service.

What is Proxy Class?

A proxy class is code that looks exactly like the class it meant to represent; however the proxy class doesn’t contain any of the application logic. Instead, the proxy class contains marshalling and transport logic. A proxy class object allows a client to access a web service as if it were a local COM object. The Proxy must be on the computer that has the web application.

What is Web Service Description Language Tool (wsdl.exe)?

This tool can take a WSDL file and generate a corresponding proxy class that you can use to invoke the web service. Alternate of generating Proxy class through WSDL.exe is you can use web reference. Web Reference automatically generates a proxy classes for a web service by setting a web reference to point to the web service.

Advantage of using Web Reference as compare to using WSDL.exe Tool is you can update changes done in web service class easily by updating web reference, which is more tedious task with WSDL.exe tool

Step 1:
Here is the code to add in web.config;

<sessionState mode=”SQLServer”
sqlConnectionString=”data source=yj-NB;UID=sa;PWD=sa123;”
cookieless=”false”
timeout=”20″/>

You don’t have to mention database name.

Step 2:

We will be executing InstallSqlState.sql script file. By default, InstallSqlState.sql is located in one of the following folders; system drive\ Windows\ Microsoft.NET\ Framework\version\

Installing the Session State Database Using the Aspnet_regsql.exe Tool
Go to command prompt
Systemdrive\WINDOWS\Microsoft.NET\Framework\version\

aspnet_regsql.exe -S yj-NB -U sa -P sa123 -d ASPstate -ssadd -sstype c

yj-NB: computer name

sa123: sa password

ASPstate: Database name that will be storing session

<asp:TextBox ID=”txtAmount” runat=”server”></asp:TextBox>
<asp:RegularExpressionValidator id=”RegExVal” runat=”server”
ControlToValidate=”txtAmount” ValidationExpression=”^[0-9]{1,4}(\.[0-9]{0,3})?$”
ErrorMessage=”Enter Exact decimal value” />

Happy coding…

The Solution:

Leave the textbox control property as ReadOnly = False

In the Page Load event set the client side attribute of the textbox with the following:

txtDate.Attributes.Add(“ReadOnly”, “true”);

This way the control is included in the postback and the value is preserved but client side the user won’t be able to manually edit it.

The following meta tag will render the web site/web page in Compatibility View in IE8:

<meta http-equiv=”X-UA-Compatible” content=”IE=EmulateIE7″ />

The following meta tag will render the web site/web page in Standard Mode in IE8

<meta http-equiv=”X-UA-Compatible” content=”IE=EmulateIE8″ />

Now the simple solution to such problem is:

1. All Programs > Microsoft SQL Server 2005 > Configuration Tools > SQL Server Surface Area Configuration
2. Surface Area Configuration for Services and Connections
3. Under Database Engine select Remote Connections. Enable Local and remote connections and under that enable Using both TCP/IP and named pipes
4. Now restart all SQL Services

A bit of googling… and I have a solution for this.

I have added below small piece of code snippet in my MasterPage’s Page_Load event

if (Request.UserAgent.IndexOf(“AppleWebKit”) > 0)
{
Request.Browser.Adapters.Clear();
}

This will tell asp.net not to use an adapter when rendering the menu control. This will work for both Safari and chrome as well because they both use webkit which is how asp.net identifies Safari1Plus.

courtesy: http://dotnetslackers.com/Community/blogs/kaushalparik/default.aspx

Close Visual Studio (if its open)

GOTO > Start > Run > RegEdit

GOTO > HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\\ProjectMRUList
remove unnecessary items from list.

Similarly repeat the steps for FileMRuList
GOTO > HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\\FileMRUList
remove unnecessary items from list.

To Clear the Find and Replace List
GOTO > HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\\Find
remove unnecessary items from list.

Another Simple way is,
Create one Text file “Clear.txt” and add below contents in it

Windows Registry Editor Version 5.00

[-HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\8.0\ProjectMRUList]
[HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\8.0\ProjectMRUList]

Save and Close the file and rename is as “Clear.reg”; that is Registry file. Double Click to Run the file, this will clear the “Recent Project List” on your Visual Studio 2005 Startup Page. You can add entries for “Recent File List” and “Find and Replace List” in this same .reg file.

courtesy: http://dotnetslackers.com/Community/blogs/kaushalparik/default.aspx