Wednesday, November 19, 2014

filling DataSet by calling oracle stored procedure

Use the below code as a reference.


public void GetDatainDataset()
{

 using (OracleConnection conn = new OracleConnection(strConnStr))            {                conn.Open();

                OracleCommand cmdABC = new OracleCommand();

                cmdABC.Connection = conn;

                cmdABC.CommandType = CommandType.StoredProcedure;

                cmdABC.CommandText = Stored Procedure Name;

                cmdABC.Parameters.Add("P_RC", OracleDbType.RefCursor).Direction                 = ParameterDirection.Output;

                DataSet ds = new DataSet();

                OracleDataAdapter adapter = new OracleDataAdapter(cmdPlants);

                adapter.Fill(ds);

                ddlABC.DataSource = ds.Tables[0];

                ddlABC.DataTextField = "A";

                ddlABC.DataValueField = "B";

                ddlABC.DataBind();

                conn.Close();

                conn.Dispose();}

Monday, October 20, 2014

Wednesday, October 1, 2014

Generate c# code from *.wsdl file using WSDL Tool

Web Service Descriptor Language Tool

is used to generate the c# code from the *.wsdl file and you can use it as proxy class for prototyping

We have been assigned a small integration project. It is in inception stage so many things are not clear and we have been given one *.wsdl file to study and we tried to generate c# code from it to work on our application prototype

wsdl.exe can be found in Visual Studio 2005 at the following location

C:\Program Files\Microsoft Visual Studio 8\SDK\v2.0\Bin

you can use following command to generate the proxy class from command prompt

wsdl /out:C:\Test\out:myProxyClass.cs C:\Test\MyWsdlfile.wsdl

Now you can add the myProcyClass.cs in your project and use its methods. Please don't modify the myProcyClass.cs file as it auto generated.

Wednesday, September 10, 2014

SQL Query Column values as comma separated



Introduction


I have a table as shown below, which has Country_Code and Cities of the a country.

 I need to retrieve distinct cities in a country based on the Country_Code
column as a comma separated string.



SQL Statement


The following SQL Statement shows how it can be achieved

Begin
declare @str varchar(1000)

SELECT @str= coalesce(@str + ',' , '') + a.CountryLang_Desc 
FROM (SELECT DISTINCT CountryLang_Desc from CountryLanguages where Country_Code='IN') a

print @str 
End

Wednesday, August 13, 2014

_doPostBack and Browser back button behavior



The odd behavior of Browser Back Button on _doPostBack()



 In one of application developed in Asp.net page is not behaving as desired when browser back button is pressed.

The steps performed in the following order

1) Go to the page
2) Click a link which causes _doPostBack and navigate to new page
3) Press the browser back button
4)click on any button 

This will end up re-executing the _doPostBack() action instead of firing Button click event.

The reason or behavior is as follows
  • Back button goes back to the previous page - page is not reloaded from server!
  • Browser assigns __EVENTxxx etc. with the previous POST back values
  • The server detects the __EVENTxxxx form vars and routes events accordingly (incorrect behavior)
To overcome this behavior i had a simple solution in my mind to expire the page and empty the secure page cache.
It worked for me by introducing following code in page load event and use is at the top not in any checks like IsPostback etc.


Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Cache.SetAllowResponseInBrowserHistory(false);


Wednesday, July 16, 2014

Disable Secure Page Cache or Expire Web Page on browser button


Expire Web Page on Browser Back/Forward Button click

Why we need to expire the web page when browser back/forward button 
is clicked. It is one of the security concern that if any user using any 
public shared computer and left the browsed page open the bad guy 
can sneak peak in to your information by using browser back/ forward buttons.

There are lot of solution available but the solution is little tricky lets start

Part 1

First of all add following response properties in you Page_Load function
and don't put this code in if(!IsPostback) code block in Page_Load function 
see sample code as below

 protected void Page_Load(object sender, System.EventArgs e)
  {                    
            if (!Page.IsPostBack)
            {
                // you Logic here
               
            }
           
            Page.Response.Cache.SetCacheability(HttpCacheability.NoCache);
            Page.Response.Cache.SetNoStore();
            Page.Response.Cache.AppendCacheExtension("no-cache");
            Page.Response.Expires = 0;
          
  }

 If there is any action or postback then the below mentioned lines will work and expire the page

 Page.Response.Cache.SetCacheability(HttpCacheability.NoCache);
 Page.Response.Cache.SetNoStore();
 Page.Response.Cache.AppendCacheExtension("no-cache");
 Page.Response.Expires = 0;

Part 2

Now to add your own logic to cater pages where we don't have any postback.

Add the following code in you Page_Load function if(!IsPostBack) check 
as below

We have taken one Session variable "TimeStamp" and one ViewState variable "TimeStamp".
when the web page is loaded with any navigation link inside the application we have Session["TimeStamp"] and ViewState["TimeStamp"] variable value "null" and that means browser buttons are not clicked and we don't have to expire the Page.

Whenever the user click the browser back/forward button the ViewState will become null for that page and Session will contain the "TimeStamp" so we infer that browser button is clicked and we need to expire the page and redirect it to a page in our case we redirect to WebPageExpire.aspx .

 protected void Page_Load(object sender, System.EventArgs e)
  {                    
            if (!Page.IsPostBack)
            {
                // you Logic here
                if (isPageExpired())
                   {
                        Response.Redirect("WebPageExpire.aspx");
                   }
               else
                  {
                       string strNow = DateTime.Now.ToString();
                       Session["TimeStamp"] = strNow;
                      ViewState["TimeStamp"] = strNow;
                  }

            }
           
            Page.Response.Cache.SetCacheability(HttpCacheability.NoCache);
            Page.Response.Cache.SetNoStore();
            Page.Response.Cache.AppendCacheExtension("no-cache");
            Page.Response.Expires = 0;
          
  }



Now add the function isPageExpired() which compares the Session["TimeStamp"] and ViewState["TimeStamp"].

private bool isPageExpired()
   {
            if (Session["TimeStamp"] == ViewState["TimeStamp"])
                return false;
            else
                return true;

   }

One more thing from where ever you are navigating either asp:Button , asp:Link etc 
we have to initialize the Session["TimeStamp"]= null so that every time when we navigate legitimately our  Session and Viewstate have same value.

    protected void BtnRegister_ServerClick(object sender, System.Web.UI.ImageClickEventArgs e)
        {
            Session["TimeStamp"] = null;
            Response.Redirect("Register.aspx", false);
        }


The same logic we have to add in every page where we need secure cache disable functionality plus you have to design a page in my case i have designed the page WebPageExpire.aspx and show message to user WebPage has expired please login again.

I hope this will solve the problem and looking forward to hear from you guys.

Monday, May 19, 2014

Wednesday, February 12, 2014

Encrypt View State Data for ASP.net Application



Encrypting view state is used to reduce the chance of information disclosure and some one getting information to cause harm to the user.

In Asp.net 2.0 the support for encryption has been enhanced. Now you can define encryption of view state on Page level. Following is the implementation in the Page tag of the aspx file.

<%@ page language="c#" masterpagefile="~/MasterPage.master" inherits="Abc.Default, App_Web_Default.aspx.cdcab7d2" validaterequest="false" theme="ABC" viewstateencryptionmode="Always" enableEventValidation="false" %>

The attribute ViewStateEncryptionMode  has three values.
1) Auto
2) Always
3) Never

The default for ViewStateEncryptionMode is Auto.

We can also set its value in the web.config file as 

<configuration>   
   <system.web>
      <pages ViewStateEncryptionMode="Always" />
   </system.web>

</configuration>

Sunday, January 12, 2014

How to access a radio button selected Boundfield value from a GridView in javascript


function RefreshParent()
{
//get the gridview object
var gv = document.getElementById("grdViewBrand");
//get the gridview input object collection
var rbs = gv.getElementsByTagName("input");
//Traverse the input object collection
for (var i = 0; i < rbs.length; i++)
{
//Check for the checked radio button
if (rbs[i].type == "radio")
{
if (rbs[i].checked)
{
//get the bound field value from the position where check box is checked
// [i+1] is due to gridview dataBoundField includes header
row also which is not present in input collection
var brandName = gv.rows[i+1].cells[0].innerText;
break;
}
}
}

Description

Get the gridview object and its inputs elements.
Traverse through the (input)collection and get the
selected Radio Button row.

Now from the griview object get the rows position and the cell
and call its inner text property