Microsoft Dot Net Master

Monday, September 19, 2011

What is Stored Procedure?

A stored procedure is a named group of SQL statements that have been previously created and stored in the server database. Stored procedures accept input parameters so that a single procedure can be used over the network by several clients using different input data. And when the procedure is modified, all clients automatically get the new version. Stored procedures reduce network traffic and improve performance. Stored procedures can be used to help ensure the integrity of the database.

e.g. sp_helpdb, sp_renamedb, sp_depends etc.

What is normalization?

Database normalization is a data design and organization process applied to data structures based on rules that help build relational databases. In relational database design, the process of organizing data to minimize redundancy. Normalization usually involves dividing a database into two or more tables and defining relationships between the tables. The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database via the defined relationships.

What is RDBMS?

Relational Data Base Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be created and maintained across and among the data and tables. In a relational database, relationships between data items are expressed by means of tables. Interdependencies among these tables are expressed by data values rather than by pointers. This allows a high degree of data independence. An RDBMS has the capability to recombine the data items from different files, providing powerful tools for data usage.

Friday, September 16, 2011

Adding Dynamic Meta Tags with Master Pages in ASP.NET using C #

Today each and every website is getting dynamic, every website for example have just on page and is being used to display the contents for various categories, hence the need for the dynamic meta title, meta description and meta keywords arises especially for implementing Search Engine Optimization(SEO) properly on your website having dynamic pages.

In a website what people do is create a Master Page and then this Master Page further contains a number of content or child pages, now what we want to have is having separate meta title, meta description and meta keywords for every child page, but here is the problem as once you run you run your website – preference is given to the meta title, meta description and meta keywords you have given in you Master Page and hence all the child pages will have same meta title, description and keywords.

Basically In ASP.NET you do not have any direct function to re write the title,description and keywords when you are working with Master Pages. To solve this problem I have written some sample code:

Firstly in your master page find this code

< head runat=”server”>
< title>Untitled Page< /title>

Than Replace it with the following code :

< head runat=”server” id=”master_Head”>
< meta name=”description” runat=”server” id=”master_Description” content=”" />
< meta name=”keywords” runat=”server” id=”master_keywords” content=”" />
< title>Untitled Page< /title>

That’s all you have to change in your master page.
Now in your child or content page include one Header File:

using System.Web.UI.HtmlControls;

Once all this done, now in your child or content page , on load write following code:

void Page_Load(Object sender, EventArgs e)
{
    HtmlHead objHead = new HtmlHead();
    objHead = (HtmlHead)Master.FindControl(“master_Head”);
    HtmlMeta objMetaDescription = (HtmlMeta)objHead.FindControl(“master_Description”);
    HtmlMeta objMetaKeywords = (HtmlMeta)objHead.FindControl(“master_keywords”);

    Title = “[Write You Title Here]“;
    objMetaDescription.Content = “[Write You Description Here]“;
    objMetaKeywords.Content = “[Write You Keywords Here]“;

}

Tuesday, September 6, 2011

Unable to cast object of type 'System.Web.UI.UpdatePanel' to type 'System.Web.UI.WebControls.GridViewRow'.

DropDownList select = (DropDownList)sender;
GridViewRow row = (GridViewRow)select.NamingContainer

Thursday, September 1, 2011

Show Current User Count On Your Website

Web application contained a file called the "global.asax". The Global.asax file is event driven. It can contain four event procedures: Application_OnStart, Application_OnEnd, Session_OnStart, and Session_OnEnd.

<%@ Application Language="C#" %>

<script runat="server">

    void Application_Start(object sender, EventArgs e)
    {
        // Code that runs on application startup
        Application["WhoOn"] = 0;

    }

    void Application_End(object sender, EventArgs e)
    {
        // Code that runs on application shutdown

    }

    void Application_Error(object sender, EventArgs e)
    {
        // Code that runs when an unhandled error occurs

    }

    void Session_Start(object sender, EventArgs e)
    {
        // Code that runs when a new session is started
        Application.Lock();
        Application["WhoOn"] =Convert.ToInt32(Application["WhoOn"]) + 1;
        Application.UnLock();

    }

    void Session_End(object sender, EventArgs e)
    {
        // Code that runs when a session ends.
        // Note: The Session_End event is raised only when the sessionstate mode
        // is set to InProc in the Web.config file. If session mode is set to StateServer
        // or SQLServer, the event is not raised.
        Application.Lock();
        Application["WhoOn"] =Convert.ToInt32( Application["WhoOn"]) - 1;
        Application.UnLock();

    }

</script>

Then to display the count on any ".aspx" page in your web site just do something like this.

<%= Application("WhoOn") %> USERS CURRENTLY ONLINE

Now, the Session_OnEnd part basically means that if a user has no activity for a period of time that (1) will be subtracted from the current user count. That time period being whatever you have the Session.Timeout set to. This means that if your Session.Timeout is set to 20 minutes that it may take up to 20 minutes for the count to update after a user leaves.

The other thing to realize is that a user can inflate the count by closing their browser and coming back to your site over and over. This problem takes care of it itself over time as all those counts will eventually expire and go away on their own but it is something to be aware of. Sometimes you'll notice this happen and it will be some jerk messing around to see if they can make your count go up. Other times it will be search engine bots indexing your site that cause the count to spike.

Also remember that if the web is not set up to run as an application the "global.asax" will not run. You'll need to make sure the web is an application. Most Virtual Domains are by default, but sub webs usually are not.

For the sub webs to run the 'global.asax" they need to be an application as the root usually is. In NT this is accomplished via the Internet Service Manager under the properties of the sub web you want to make an application

Tuesday, August 30, 2011

Asp.net WebService or Creating and Consuming WebService in asp.net or Create and call webservice in asp.net or how to create webservice and how to use webservice in asp.net

What is Web Service?

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. The Web serivce consumers are able to invoke method calls on remote objects by using SOAP and HTTP over the Web. WebService is language independent and Web Services communicate by using standard web protocols and data formats, such as

HTTP
XML
SOAP

Advantages of Web Service

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

Examples for 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 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.

Frequently used word with web services

What is SOAP?

SOAP (simple object access protocol) is a 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 detail regarding using web service and Method and Properties provided by web service and URLs from which those methods can be accessed and Data Types 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 contains URL for the WSDL, URL for the documentation and URL to which SOAP messages should be sent.

Before start creating web service first create one table in your database and give name UserInformation in my code I am using same name and enter some dummy data for our testing purpose

Column Name	Data Type	Allow Nulls
UserId	Int(Set Identity=true)	No
UserName	Varchar(50)	Yes
FirstName	Varchar(50)	Yes
LastName	Varchar(50)	Yes
Location	Varchar(50)	Yes

Now we will see how to create new web service application in asp.net

Open visual studio ---> Select File ---> New ---> Web Site ---> select ASP.NET Web Service

Now our new web service ready our webservice website like this

Now open your Service.cs file in web service website to write the code to get the user details from database

Before writing the WebMethod in Service.cs first add following namespaces

using System.Xml;

using System.Configuration;

using System.Data;

using System.Data.SqlClient;

After adding namespaces write the following method GetUserDetails in Service.cs page

[WebMethod]

public XmlElement GetUserDetails(string userName)

{

SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["dbconnection"].ToString());

con.Open();

SqlCommand cmd = new SqlCommand("select * from UserInformation where UserName like @userName+'%'", con);

cmd.Parameters.AddWithValue("@userName", userName);

cmd.ExecuteNonQuery();

SqlDataAdapter da = new SqlDataAdapter(cmd);

// Create an instance of DataSet.

DataSet ds = new DataSet();

da.Fill(ds);

con.Close();

// Return the DataSet as an XmlElement.

XmlDataDocument xmldata = new XmlDataDocument(ds);

XmlElement xmlElement = xmldata.DocumentElement;

return xmlElement;

}

Here we need to remember one point that is adding [WebMethod] before method definition because we need to access web method pulically otherwise it’s not possible to access method publically. If you observe above code I converted dataset to XmlElement t because sometimes we will get error like return type dataset invalid type it must be either an IListSource, IEnumerable, or IDataSource to avoid this error I converted dataset to XmlElement.

Here we need to set the database connection in web.config because here I am getting database connection from web.config

</connectionStrings>

Now run your web service it would be like this

Our web service is working fine now we need to know how we can use webservice in our application? Before to know about using web service in application first Deploy your webservice application in your local system if you want to know how to deploy application in your local system check this link deploy application in local system

How to Use Web service in web application?

By using this webservice we can get the user details based on username. For that first create one new web application

Open visual studio ---> Select File ---> New ---> Web Site ---> select ASP.NET Web Site

After creation of new website right click on solution explorer and choose “Add web reference” that would be like this

After select Add Web reference option one window will open like this

Now enter your locally deployed web service link and click Go button after that your web service will found and window will looks like this

Now click on Add Reference button web service will add successfully. Now open your Default.aspx page and design like this

<title>Getting Data from WebService</title>

</head>

<body>

<div>

<table>

<tr>

<td>

<b>Enter UserName:</b>

</td>

<td>

<asp:TextBox ID="txtUserName" runat="server"></asp:TextBox>

</td>

<td>

<asp:Button ID="btnSubmit" runat="server" Text="Submit" onclick="btnSubmit_Click" />

</td>

</tr>

</table>

</div>

<div>

<asp:GridView ID="gvUserDetails" runat="server" EmptyDataText="No Record Found">

</asp:GridView>

</div>

</form>

</body>

</html>

Now in code behind add following namespaces

using System.Data; using System.Xml;

After adding namespaces write the following code in code behind

protected void Page_Load(object sender, EventArgs e)

{

if(!IsPostBack)

{

BindUserDetails("");

}

protected void BindUserDetails(string userName)

{

localhost.Service objUserDetails = new localhost.Service();

DataSet dsresult = new DataSet();

XmlElement exelement = objUserDetails.GetUserDetails(userName);

if(exelement!=null)

{

XmlNodeReader nodereader = new XmlNodeReader(exelement);

dsresult.ReadXml(nodereader, XmlReadMode.Auto);

gvUserDetails.DataSource = dsresult;

gvUserDetails.DataBind();

}

else

{

gvUserDetails.DataSource = null;

gvUserDetails.DataBind();

}

protected void btnSubmit_Click(object sender, EventArgs e)

{

BindUserDetails(txtUserName.Text);

}

Now run your application and check output