.Net technology: interview Questions

Summary

ASP.NET only allows a single authentication mode to be configured for each application. Some applications may require different modes for different paths. For example, if an application uses Forms authentication for users of the public site, and Windows authentication for users of the administration site.

Resolution

One solution is to create two separate applications; one for the public site using Forms authentication, and one for the administration site using Windows authentication. However, this will mean that resources in the public application cannot be accessed from the administration application using app-relative paths (e.g. /images/logo.jpg).

A better solution is to use the global.asax file to handle theFormsAuthentication_OnAuthenticate event, and apply Windows authentication where appropriate.

In IIS, open the properties of the administration folder;
Under "Directory Security", edit the anonymous access and authentication settings, and disable anonymous access;
Edit the web.config file, and configure the application to use Forms authentication;
Add the following code to the global.asax file in the root of the application:

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

<%@ Import Namespace="System.Security.Principal" %>

<%@ Import Namespace="System.Web" %>

<%@ Import Namespace="System.Web.Security" %>

public void FormsAuthentication_OnAuthenticate(object sender, FormsAuthenticationEventArgs e)

{

if (null == e) throw new ArgumentNullException("e");

// Check that we have a Windows user

WindowsIdentity winUser = e.Context.Request.LogonUserIdentity;

if (null == winUser) return;

// Check that the path allows Windows authentication

string path = VirtualPathUtility.ToAppRelative(e.Context.Request.Path);

if (!IsWindowsAuthenticated(path, e.Context)) return;

// Don't allow guest accounts to access

if (winUser.IsAnonymous || winUser.IsGuest || winUser.IsSystem) return;

WindowsPrincipal winPrincipal = new WindowsPrincipal(winUser);

if (winPrincipal.IsInRole("Guests")) return;

e.User = winPrincipal;

}

private static bool IsWindowsAuthenticated(string path, HttpContext context)

{

if (string.IsNullOrEmpty(path)) throw new ArgumentNullException("path");

if (null == context) throw new ArgumentNullException("context");

// Check that the path starts with the restricted folder:

if (path.StartsWith("/restricted/", StringComparison.OrdinalIgnoreCase)) return true;

return false;

}

</script>

5. Requests to the administration folder will now use Windows authentication; the rest of the site will continue to use Forms authentication

1 How to get client date and time

Ans- How to get client date and time

You can use java script function to show the date and time.

function displayTime()

{

var localTime = new Date();

var year= localTime.getYear();

var month= localTime.getMonth() +1;

var date = localTime.getDate();

var hours = localTime .getHours();

var minutes = localTime .getMinutes();

var seconds = localTime .getSeconds();

var div=document.getElementById("div1");

div.innerText=year+"-"+month+"-"+date+" "+hours+":"+minutes+":"+seconds;

}

</script>

Then you can call it at web page.

</form>

</body>

Related posts: http://forums.asp.net/p/1247758/2303034.aspx

2 How to access a control by using JavaScript

Ans- 2 How to access a control by using JavaScript

Reference the ClientID property (or UniqueID) of the control in the JavaScript.

protected void Page_Load(object sender, EventArgs e)

{

Button btn= new Button();

btn.ID = "btn5";

btn.Attributes.Add("runat", "server");

btn.Attributes.Add("onclick", "pop('" + btn.ClientID + "')");

btn.Text = "Test";

this.form1.Controls.Add(btn);

}

function pop(InputBoxID)

{

var InputControl = document.getElementById(InputBoxID);

alert(InputControl.value);

}

Or you can use the following method:

btn.Attributes.Add("onclick", "pop(this)");

function pop(InputBox)

{

alert(InputBox.value);

}

Related posts: http://forums.asp.net/p/1239593/2260331.aspx#2260331

3 How to invoke a server-side function with JavaScript

Ans- 3 How to invoke a server-side function with JavaScript

Firstly, you can drag a server button and put the server function into the button Click even,

protected void Button1_Click(object sender, EventArgs e)

{

FunctionName();

}

Secondly, you can call the server function at JavaScript by using the following code,

document.getElementById("Button1").click();

Related posts: http://forums.asp.net/p/1242420/2274228.aspx

4 How to retrieve server side variables using JavaScript code

Ans- 4 How to retrieve server side variables using JavaScript code [top]

<asp:HiddenField ID="HiddenField1" runat="server" />

public partial class LoginDemo : System.Web.UI.Page

{

private string str="hello";

protected void Page_Load(object sender, EventArgs e)

{

HiddenField1.Value=str;

}

Then you can access the control HiddenField1 using javascipt:

Var tt=document.getElementByID(“HiddenField1”);

alert(tt.value);

</script>

Related posts: http://forums.asp.net/p/1000655/1319119.aspx

5 How to assign a value to a hidden field using JavaScript in ASP.NET

Ans- 5 How to assign a value to a hidden field using JavaScript in ASP.NET

We can use JavaScript to set the value of a hidden control and get its value at the server after a

var str=”hello”

document.getElementByID(“Hidden1”).value=str

</script>

protected void Page_Load(object sender, EventArgs e)

{

string str=request["Hidden1"].ToString();

}

Related posts: http://forums.asp.net/p/1262153/2362090.aspx

6 How to register the JavaScript function at Code-Behind

Ans- 6 How to register the JavaScript function at Code-Behind

Use ResterStartupScript

this.Page.ClientScript.RegisterStartupScript(this.GetType(),"alert","<script>aler

Use Literal control,

private void Button2_Click(object sender, System.EventArgs e)

{

string str;

str="<script language='JavaScript'>";

str+="selectRange()";

str+="<script>";

Literal1.Text=str;

}

Related posts: http://forums.asp.net/p/981603/1257057.aspx#1257057

7 How to display images with a delay of five seconds

Ans- 7 How to display images with a delay of five seconds [top]

With this script you can see clickable images rotating in real-time without requiring banner rotat

reloads/refreshes .You should see a new banner rotating every 5 seconds:

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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org

transitional.dtd">

</script>

<title>JavaScript</title>

var image="";

var banners=0;

function loadbanners() {

if (banners==1)

{

image="images/AJAX.gif";

}

if (banners==2)

{

image="images/ASPDotNet.gif";

}

if (banners==3)

{

image=" images/MSDN.gif";

}

function cycle()

{

if (++banners > 3)

banners=1;

loadbanners();

document.getElementById("banner1").src =image;

window.setTimeout('cycle();',5000);

}

</script>

</head>

<div>

</div>

</form>

</body>

</html>

http://forums.asp.net/p/1213103/2147140.aspx

8 How to get browser screen settings and apply it to page controls

Ans- 8

How to get browser screen settings and apply it to page controls [top]

You can use the JavaScript, suppose the control type is <image>, see the code below:

<html>

<body>

<img src="http://www.microsoft.com/library/toolbar/3.0/images/banners/ms_masthead

var winWidth = 0;

var winHeight = 0;

function resizeImage(){

var img=document.getElementById("testImage")

if (window.innerWidth)

winWidth = window.innerWidth;

else if ((document.body) && (document.body.clientWidth))

winWidth = document.body.clientWidth;

if (window.innerHeight)

winHeight = window.innerHeight;

else if ((document.body) && (document.body.clientHeight))

winHeight = document.body.clientHeight;

if (document.documentElement && document.documentElement.clientHeight &&

document.documentElement.clientWidth)

{

winHeight = document.documentElement.clientHeight;

winWidth = document.documentElement.clientWidth;

}

img.width= winHeight;

img.width= winWidth;

}

</script>

</body>

</html>

Please remove the control style if it is present.

Related posts:http://forums.asp.net/p/1228180/2212987.aspx

9 How to clear the session when the user closes a window

Ans- 9 How to clear the session when the user closes a window [top]

Use the code,

function window.onbeforeunload()

{

var xmlHttp;

try

{

// Firefox, Opera 8.0+, Safari

xmlHttp=new XMLHttpRequest();

}

catch (e)

{

// Internet Explorer

try

{

xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");

}

catch (e)

{

try

{

xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");

}

catch (e)

{

alert("Your browser does not support AJAX!");

return false;

}

if(event.clientX>document.body.clientWidth&&event.clientY<0||event.altKey)

{

xmlhttp.open("GET","exit.aspx",false);

xmlhttp.send();

}

</script>

Related posts: http://forums.asp.net/p/1237752/2255401.aspx

These are some tricks which have to use a fresher web gardener (developer)

.Net technology

About Me

Tuesday, October 18, 2011

Using multiple authentication modes in a single ASP.NET application

Tuesday, October 4, 2011

Javascript Tricks (No Interview Questions)

disqus

Popular Posts