Saturday, June 27, 2009

Empty the Recycle Bin

Empty the Recycle Bin

Ths following code is used to empty the recycle bin using Microsoft .NET Framework, ASP.NET, Visual C# (CSharp, C Sharp, C-Sharp) Developer Training, Visual Studio

The namespace we have to use is:

using System.Runtime.InteropServices;
 
then create an enum for recylceflags like
 
enum RecycleFlgs : uint
{
   SHERB_NOCONFIRMATION = 0x00000001,
   SHERB_NOPROGRESSUI   = 0x00000002,
   SHERB_NOSOUND        = 0x00000004
}
 
creating an extern
 
[DllImport("Shell32.dll", CharSet = CharSet.Unicode)]
static extern uint EmptyRecycleBin 
        (IntPtr hwnd, 
        string pszRootPath,
        RecycleFlgs dwFlags);
               
Now the main function to call  the above defined code
 
public static void Main()
{
    uint result = EmptyRecycleBin (IntPtr.Zero, null, 0);
    Console.WriteLine ("Result: {0}", result);
}


Thanks and Regards
Meetu Choudhary
http://www.msdotnetmentor.com/

Thursday, June 18, 2009

Move Cursor to the Last Index in The Texbox

Code for script section in the head

<script type="text/javascript" language="javascript">
function moveindex() {
var me2 = document.selection.createRange();
me2.moveStart("character", 200);
me2.select();
}
</script>

code for calling the function in the body section

<asp:TextBox ID="TextBox1" runat="server" onfocus="moveindex()"/>


Thanks and Regards
Meetu Choudhary

Wednesday, June 17, 2009

Showing Image Dynamically

This piece of code demonstrate that when we take mouse on a particular image the place holder for the image displays the corresponding image... here goes the code
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >

<head>

<title>Meetu Choudhary</title>

Script for head section


<script language="javascript" type="text/javascript">

function showimage(imagename)

{

targetimage.src="images/" + imagename;

}

</script>

</head>

Body will have these contents..


<body>
<table width="694" height="525" border="0">

<tr>

<td width="141" height="95" valign="top">

<img src="images/image1.jpg" onmouseover="showimage('image1.jpg')" width="141" height="93">

</td>

<td width="141">

<img src="images/image2.jpg" width="141" height="93" onmouseover="showimage('image2.jpg')">

</td>

<td width="141">

<img src="images/image3.jpg" width="141" height="93" onmouseover="showimage('image3.jpg')">

</td>

<td width="139">

<img src="images/image4.jpg" width="141" height="93" onmouseover="showimage('image4.jpg')">

</td>

<td width="98">

<img src="images/image5.jpg" width="141" height="93" onmouseover="showimage('image5.jpg')">

</td>

</tr>

<tr>

<td height="424">&nbsp;</td>

<td colspan="3" valign="top">

<img id="targetimage" src="images/image1.jpg" width="420" height="252"/>

</td>

<td>&nbsp;</td>

</tr>

</table>

</body>

</html>


To download the zip folder conating the demo of the article click here



Thanks and Regards

Meetu Choudhary

Thursday, June 11, 2009

Encrypt And Decrypt Using Digital Signatures

Encrypt And Decrypt Using Digital Signatures


Now in continutaion to my earlier artcile the mirroe link of the article here I am going to describe how we can use the digital signatures for the purpose of Encryption and Decryption.

The Following code will show how we can encrypt the plain text.

Encryption


#region Encryption

public string GetEncryptedText(string PlainStringToEncrypt)

{

try

{

string PlainString = PlainStringToEncrypt.Trim();

byte[] cipherbytes = ASCIIEncoding.ASCII.GetBytes(PlainString);

RSACryptoServiceProvider rsa = (RSACryptoServiceProvider)x509_2.PublicKey.Key;

byte[] cipher = rsa.Encrypt(cipherbytes, false);

return Convert.ToBase64String(cipher);

}

catch (Exception e)

{

throw e;

}

}
#endregion

Now once we have encrypted text we need to decrypt it. the following section of code will demonstrate how to decrypt that encrypted text.

Decryption


#region Decryption

public string GetDecryptedText(string EncryptedStringToDecrypt)

{

try

{



try

{

byte[] cipherbytes = Convert.FromBase64String(EncryptedStringToDecrypt);

if (x509_2.HasPrivateKey)

{

RSACryptoServiceProvider rsa = (RSACryptoServiceProvider)x509_2.PrivateKey;

byte[] plainbytes = rsa.Decrypt(cipherbytes, false);

System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();

return enc.GetString(plainbytes);

}

else

{

throw new Exception("Certificate used for has no private key.");

}

}

catch (Exception e)

{

return e.Message;

}

}

catch

{

return EncryptedStringToDecrypt;

}

}
#endregion



Thanks and Regards

Meetu Choudhary

Tuesday, June 9, 2009

How do I specify more than one parameter for my HyperlinkColumn?

How do I specify more than one parameter for my HyperlinkColumn?
================================================================
Many times will developing the applications we come accross the thing that how i can pass more then one parameter in the query string which is genertated by the datagrid or gridviews... once i was developing an application and the same problem came accross at that time i was quite new to ASP.net and was stucked there did lots of googleing and found the answer now today i want to share that piece of code as an example may be i may help you to avoid a bit burdden of yours to find the code

Here i have encoded the querstring or the URL to avoid some unwanted error which are normaly genertaed due to spaces and special characters.
the code follows like

[code]
< asp:DataGrid id="DataGrid1" runat="server" AutoGenerateColumns="False" >
< Columns >
< asp:TemplateColumn HeaderText="Sample Column" >
< ItemTemplate >
< asp:Hyperlink runat="server" Text=' < %#Container.DataItem("TextVal")% >' NavigateUrl=' < %# "page.aspx?Param1=" & Server.UrlEncode(Container.DataItem("Val1")) & "&Param2=" & Server.UrlEncode(Container.DataItem("Val2"))%>'/>
</itemtemplate >
</asp:TemplateColumn >
</columns >
[/code]




Thanks and regards
Meetu Choudhary

Monday, June 8, 2009

Shortcut Keys of Edit Menu in VS 2008

Check the follwoing Link
http://www.dotnetspider.com/resources/28921-Shortcut-Keys-Edit-Menu-VS.aspx

Organize Usings

Once we have created our class. In that class we use the using statment at the top of the class.To include namespaces in our class. But sometimes we realize after compeleting the code of that calss we have used some extra namespaces which are of no use in th class to remove all those unused using statment. we can use InteliSense in the edit menu. in the submenu of InteliSense we will find the option organize usings. and in its sub menu we hve the options to remove unused usings to sort usings and to remove and sort usings.


Thanks and Regards
Meetu Choudhary

Friday, June 5, 2009

Format document

To format any document (.cs,XML,aspx,HTML etc) in visual studio 2008
use the following key combinations:
To format whole document : ctrl +k ,(followed by) ctrl + d
To format the selection : ctrl +k, (followed by) ctrl +f




Thanks and Regards
Meetu Choudhary

Wednesday, June 3, 2009

Accessing the properties of a digital signature

Accessing the properties of a digital signature



Now once we have selected the certificate. We need to access the properties of the certificate. Here is a small piece of code to access all the properties which may be helpful to us for any context.

before accessing these properties we have to set the certificate object. for that you can get the code from any of the two previous articles.
1. Article link , Mirror link
2. Article link , Mirror link


Now once we have the certificate (X509Certificate2 x509_2;)
we can o with the following code

[code]

///



/// Set All the Properties of the Certificate

///


public Boolean SetProperties()

{

if (x509_2 != null)

{

RSACryptoServiceProvider rsa = (RSACryptoServiceProvider)x509_2.PublicKey.Key;

_PublicKey_Key =_PublicKeyXML = rsa.ToXmlString(false);

//_PrivateKeyXML = rsa.ToXmlString(true );

_PrivateKeyXML=_Private_Key = x509_2.PrivateKey.ToXmlString(false);

_PKeyExchangeAlgorithm = x509_2.PrivateKey.KeyExchangeAlgorithm;

_PublicKey = x509_2.GetPublicKeyString();

//_PublicKey_Key = Convert.ToString(x509_2.PublicKey.Key);

_SerialNumber = x509_2.GetPublicKeyString();

_Thumbprint = x509_2.Thumbprint;

_RawCertDataString = x509_2.GetRawCertDataString();

_FriendlyName = x509_2.FriendlyName;

_HashString = x509_2.GetCertHashString();

_EffectiveDate = x509_2.GetEffectiveDateString();

_ExpirationDate = x509_2.GetExpirationDateString();

_Format = x509_2.GetFormat();

_IssuerName = x509_2.GetIssuerName();

_KeyAlgorithm = x509_2.GetKeyAlgorithm();

_KeyAlgorithmParameters = x509_2.GetKeyAlgorithmParametersString();

_CertName = x509_2.GetName();

_CertSubject = x509_2.Subject;

_CertVersion = x509_2.Version;

_SignatureAlgorithm_Value = x509_2.SignatureAlgorithm.Value;

_SignatureAlgorithm_ToString = x509_2.SignatureAlgorithm.ToString();

_SignatureAlgorithm_FriendlyName = x509_2.SignatureAlgorithm.FriendlyName;

return true;

}

else { return false; }

}

[/code]




Thanks and Regards
Meetu Choudhary

Open Certificate Stores Including Certificates in Token

Open Certificate Stores Including Certificates in Token



In My Previous article Mirror Link I have shown how to open a certificate store (Machine certificate store which is displayed in the Internet Explorer.) but the drawback of that code was it can't open the certificates stored in the token. so here is another method which will overcome the drawback stated above. It will open the certificates of the machine store as well as of the tokens.

[code]
///

/// Opens the Certificate Store of IE including the Certificates in Token

///


/// The variable passed to store the reason if function returns false

/// True if a certificate is selected and false if no certificate is selected

public Boolean OpenStoreToken(ref string popupScript)

{

x509_2 = null;

//Create and Initilaize a variable of x509Store providing the store name and the store location

X509Store st = new X509Store(StoreName.My, StoreLocation.CurrentUser);

//Create X509Certificate2Collection

X509Certificate2Collection col = new X509Certificate2Collection();

//Create X509Certificate2Collection

X509Certificate2Collection sel = new X509Certificate2Collection();

//Create X509Certificate2Enumerator

X509Certificate2Enumerator en;// =new X509Certificate2Enumerator();

//Open the Store for readonly purpose

st.Open(OpenFlags.ReadOnly);

//set the col i.e. X509Certificate2Collection to the collection of the certificates stored in the IE and the Token

col = st.Certificates;

//set the sel i.e. X509Certificate2Collection which actuly displays a dialog box for selecting an X.509 certificate from a certificate collection.

sel = X509Certificate2UI.SelectFromCollection(col, "Certificates", "Select one to sign", X509SelectionFlag.SingleSelection);

if (sel.Count > 0)

{

en = sel.GetEnumerator();

en.MoveNext();

x509_2 = en.Current;

}

st.Close();

if (x509_2 == null)

{

popupScript = "You didn't select a certificate!!!";

return false;

}

else

{

return true;

}

}



[/code]



Thanks and Regards
Meetu Choudhary

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