June 2012

Wednesday, June 20, 2012

Received MCTS Certification for WCF

Anuradha 3:47 AM Certifications No comments :

Tuesday, June 19, 2012

Rijndael Algorithm for Encryption and Decryption

I have implemented a sample code to implement encryption and decryption of string using Rijndael Algorithm

 protected void Page_Load(object sender, EventArgs e)
    {
        string clearData = "Hello, World!";
        string key = "s@1tValue";
        byte[] b = Encrypt(clearData, key);
        Response.Write("Encrypted String: " + Convert.ToBase64String(b));        
        Response.Write("--------------------------------------------------------------");
        Response.Write("Decrypted String: " + Encoding.UTF8.GetString(Decrypt(b, key)));
    }

    public static byte[] Encrypt(string iclearData, string key)
    {
        try
        {
            byte[] clearData = Encoding.ASCII.GetBytes(iclearData);
            var salt = new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 };
            var pdb = new PasswordDeriveBytes(key, salt);
            MemoryStream ms = new MemoryStream();
            var alg = Rijndael.Create();
            alg.Key = pdb.GetBytes(32);
            alg.IV = pdb.GetBytes(16);
            CryptoStream cryptoStream = new CryptoStream(ms,alg.CreateEncryptor(),CryptoStreamMode.Write);
            cryptoStream.Write(clearData, 0, clearData.Length);
             cryptoStream.FlushFinalBlock(); 
            byte[] cipherTextBytes = ms.ToArray();
            ms.Close();
            cryptoStream.Close();
            return cipherTextBytes;
        }
        catch (Exception)
        {
            throw new Exception("Encryption Failed");
        }
    }

    public static byte[] Decrypt(byte[] cipherData, string key)
    {
        try
        {
            var salt = new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 };
            var pdb = new PasswordDeriveBytes(key, salt);           
            var alg = Rijndael.Create();
            alg.Key = pdb.GetBytes(32);
            alg.IV = pdb.GetBytes(16);
            MemoryStream ms = new MemoryStream(cipherData);
            CryptoStream cryptoStream = new CryptoStream(ms,alg.CreateDecryptor(),CryptoStreamMode.Read);
            byte[] plainTextBytes = new byte[cipherData.Length];
            int decryptedByteCount = cryptoStream.Read(plainTextBytes,  0, plainTextBytes.Length);
            ms.Close();
            cryptoStream.Close();
            return plainTextBytes;
        }
        catch (Exception)
        {
            throw new Exception("Decryption Failed");
        }
    }

Monday, June 18, 2012

MCTS Certification

Anuradha 3:34 AM Certifications No comments :

Today i took my first Certification and it is on Exam 70-513: TS: Windows Communication Foundation Development with Microsoft .NET Framework 4
I got certified with score 861/1000

Friday, June 8, 2012

How to display rss feed in asp.net

Anuradha 4:02 AM C#4.0 No comments :

In this post I will show you how to display rss feed in asp.net using XmlDataSource and DataList control.
Create a web page name it as RSSFeed.aspx

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="txtUrl" runat="server" Width="349px"></asp:TextBox>
        <asp:Button ID="btnLoad" runat="server" Text="Load" OnClick="btnLoad_Click" />
        <asp:DataList ID="dlRss" runat="server">
            <ItemTemplate>
                <%#XPath("title") %>
                <i>
                    <%#XPath("description") %></i> <i>
                        <%#XPath("pubdate") %></i> <b><a href="<%#XPath("link") %>">
                            <%#XPath("link") %></a></b>
            </ItemTemplate>
        </asp:DataList>
        <asp:XmlDataSource ID="xml" runat="server" XPath="rss/channel/item"></asp:XmlDataSource>
    </div>
    </form>
</body>
</html>

protected void btnLoad_Click(object sender, EventArgs e)
    {        
        if (txtUrl.Text != "")
        {
            xml.DataFile = txtUrl.Text;
            dlRss.DataSourceID = xml.ClientID;
        }
    }

Wednesday, June 6, 2012

“click here to reload the designer” message when creating new SL application in Visual Studio 2010

Anuradha 3:00 AM SilverLight , VS2010 No comments :

Generally Visual Studio 2010 doesn't come with Silverlight 4 . They have Silverlight 3 capability only.
If you want to develop Silverlight 4 app in any of the above two IDEs, you need to install additional add-on that can be installed from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=b3deb194-ca86-4fb6-a716-b67c2604a139 (34 MB).
Once you have installed, you should start developing Silverlight 4 app.

But when you get the error message “click here to reload the designer” message with the Details pane referring to a null reference exception "object reference not set to an instance of an object"
Just uninstall all the Silver Light named programs from Control Panel.
And follow the process mentioned above .
Don't try to install SilverlightDeveloper.exe before installing SilverlightTools.exe because results in the above error.

Hope this helps!

Friday, June 1, 2012

Dynamic SQL Query

Anuradha 3:41 AM SQLServer No comments :

SQL Server different ways of running a dynamic SQL Query statement:
1.Query with parameters
2.EXEC
3.Sp_Executesql

1. Query with parameters
It is as simple as the following example shows.

DECLARE @emp varchar(75)
SET @emp = 'Anu'
SELECT * FROM employee WHERE EmpName = @emp

2. EXEC

SQL statement is built on the fly

DECLARE @sqlCommand varchar(1000)
DECLARE @columnList varchar(75)
DECLARE @ emp varchar(75)
SET @columnList = 'EmpId, Salary, EmpName'
SET @emp = '''Anu'''
SET @sqlCommand = 'SELECT ' + @columnList + ' FROM employee WHERE EmpName = ' + @emp
EXEC (@sqlCommand)

3. sp_executesql

DECLARE @sqlCommand nvarchar(1000)
DECLARE @columnList varchar(75)
DECLARE @emp varchar(75)
SET @columnList = 'EmpId, Salary, EmpName'
SET @emp = '''Anu'''
SET @sqlCommand = 'SELECT ' + @columnList + ' FROM employee WHERE EmpName = ' + @emp
EXECUTE sp_executesql @sqlCommand, N'@emp nvarchar(75)', @emp = @emp

So here are three different ways of writing dynamic queries

SQL Server With Syntax in Dynamic Query

Anuradha 3:29 AM SQLServer No comments :


Declare @sql nvarchar(max)
DEclare @tab nvarchar(50)
set @tab= 'Employeetable'
-- To get column list of table in database
select 'select * from '+@tab+' where ' +  name + '=True' as query1 into Temptable 
from sys.columns where object_id in(select object_id  from sys.tables where name=''+@tab+'') 

declare @colcount int
declare @counter int
DEclare @cmd nvarchar(max)
set @counter=0
select @colcount =COUNT(*) from Temptable
WHILE @counter < @colcount
    BEGIN
      SET @counter = @counter + 1
      SET @cmd =';WITH MyCte AS ( select   query1, RowNum = row_number() OVER ( order by query1 )  
from Temptable ) SELECT query1 FROM MyCte WHERE RowNum = '+CONVERT(nvarchar,@counter)
     EXECUTE sp_executesql @cmd
    END
      
-- The above example is example for executing Dynamic Query Resultset
-- ;WITH MyCte AS ( select   query1, RowNum = row_number() OVER ( order by query1 )  from Temptable ) 
--SELECT query1 FROM MyCte WHERE RowNum = 2
   
DECLARE @sqlCommand nvarchar(1000)
DECLARE @columnList varchar(75)
DECLARE @city varchar(75)
SET @columnList = 'EmpId, Salary, EmpName'
SET @city = 'Anu'
SET @sqlCommand = 'SELECT ' + @columnList + ',ROW_NUMBER() OVER( order by EmpId) as rownum 
FROM Employee WHERE EmpName = @city'
EXECUTE sp_executesql @sqlCommand, N'@city nvarchar(75)', @city = @city
set @sqlCommand = 'SELECT  *,ROW_NUMBER() OVER( order by query1) as rownum  from Temptable'
EXECUTE sp_executesql @sqlCommand

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