You&#39;re close. You&#39;ll need to use the Response object to write back to the browser:

    if ( Request.Cookies[&quot;MyCookie&quot;] != null )
    {
        var c = new HttpCookie( &quot;MyCookie&quot; );
        c.Expires = DateTime.Now.AddDays( -1 );
        Response.Cookies.Add( c );
    }

More information on MSDN, [How to: Delete a Cookie][1].


  [1]: http://msdn.microsoft.com/en-us/library/ms178195.aspx

Cookies are stored on the client, not on the server, so Session.Clear won&#39;t affect them. Also, Request.Cookies is populated by IIS and given to your page with each request for a page; adding/removing a cookie from that collection does nothing.

Try performing a similar action against Response.Cookies. That should cause your client to overwrite the old cookie with the new one, causing it to be expired.

I did this and it worked for clearing (not deleting) a session cookie:

    HttpContext.Response.Cookies.Set(new HttpCookie(&quot;cookie_name&quot;){Value = string.Empty});

Based on Metro&#39;s response I created this extension method to make the code reusable in any controller.


    /// &lt;summary&gt;
    /// Deletes a cookie with specified name
    /// &lt;/summary&gt;
    /// &lt;param name=&quot;controller&quot;&gt;extends the controller&lt;/param&gt;
    /// &lt;param name=&quot;cookieName&quot;&gt;cookie name&lt;/param&gt;
    public static void DeleteCookie(this Controller controller, string cookieName)
    {
        if (controller.HttpContext.Request.Cookies[cookieName] == null)
                return; //cookie doesn&#39;t exist
    
        var c = new HttpCookie(cookieName)
                    {
                        Expires = DateTime.Now.AddDays(-1)
                    };
        controller.HttpContext.Response.Cookies.Add(c);
    }


I&#39;m using the new ImageIO framework in iOS 4.1. I successfully retrieve the exif metadata using the following:

    CFDictionaryRef metadataDict = CMGetAttachment(sampleBuffer, kCGImagePropertyExifDictionary , NULL);

Reading it out, it appears valid. Saving an image out works, but there is never any exif data in the image.

        CGImageDestinationRef myImageDest = CGImageDestinationCreateWithURL((CFURLRef) docurl, kUTTypeJPEG, 1, NULL);
        
        // Add the image to the destination using previously saved options. 
        CGImageDestinationAddImage(myImageDest, iref, NULL);
        
        //add back exif
        NSDictionary *props = [NSDictionary dictionaryWithObjectsAndKeys:
                                [NSNumber numberWithFloat:.1], kCGImageDestinationLossyCompressionQuality,
                               metadataDict, kCGImagePropertyExifDictionary, //the exif metadata
                                                            nil];
                               
                              //kCGImagePropertyExifAuxDictionary
        
        CGImageDestinationSetProperties(myImageDest, (CFDictionaryRef) props);
        
        // Finalize the image destination. 
        bool status = CGImageDestinationFinalize(myImageDest);



Problem setting exif data for an image

Can some describe and help me understand **all** the svn symbols, like `A`, `M` , `G` , `?` and `&gt;` ?

Describe the SVN symbols

Ok, so I really think I am doing this right, but the cookies aren&#39;t being cleared.

     Session.Clear();
     HttpCookie c = Request.Cookies[&quot;MyCookie&quot;];
     if (c != null)
     {
         c = new HttpCookie(&quot;MyCookie&quot;);
         c[&quot;AT&quot;] = null;
         c.Expires = DateTime.Now.AddDays(-1);
         Request.Cookies.Add(c);
     }

     return RedirectToAction(&quot;Index&quot;, &quot;Home&quot;);

When the redirect happens, it finds the cookie again and moves on as though I never logged out. Any thoughts?



How do you clear cookies using asp.net mvc 3 and c#?

Ok, so I really think I am doing this right, but the cookies aren't being cleared.
<pre><code class="hljs language-ini"> Session.Clear();
 HttpCookie c = Request.Cookies["MyCookie"];
 if (c != null)
 {
 c = new HttpCookie("MyCookie");
 c["AT"] = null;
 c.Expires = DateTime.Now.AddDays(-1);
 Request.Cookies.Add(c);
 }

 return RedirectToAction("Index", "Home");
</code></pre>
When the redirect happens, it finds the cookie again and moves on as though I never logged out. Any thoughts?

What is the use of [`Enumerable.Zip`](https://msdn.microsoft.com/en-us/library/dd267698.aspx) extension method in Linq?

What is the use of Enumerable.Zip extension method in Linq?

I tried writing an algorithm to simplify a decimal to a fraction and realized it wasn&#39;t too simple. 

Write `0.333333...` as `1/3` for example.

Or `0.1666667`, which is `1/6`.

Surprisingly I looked online and all the codes I found where either too long, or wouldn&#39;t work in some cases. What was even more annoying was that they didn&#39;t work for recurring decimals. I was wondering however whether there would be a mathematician/programmer here who understands all the involved processes in simplifying a decimal to a fraction. Anyone?

Algorithm for simplifying decimal to fractions

When I am compiling my .csproj file using .NET Framework 4.0 MSBUILD.EXE file, I am getting an error: &quot;lable01&quot; not found in the current context of &quot;website01.csproj&quot;.

Actually, I need to add every ASP.NET page with its code-behind file&#39;s reference. I&#39;ve done it, it&#39;s working fine, but the above error is pending.

I hope it means that I need to add form name &quot;LABLE01&quot; in that .csproj file, but I do not know the syntax. Anybody please do provide me with the syntax to add form name in .csproj file.

How to edit .csproj file

I&#39;m trying to compile my excel addin using C# 4.0, and started to get this problem when building my project in Visual Studio. It&#39;s important to tell you that I haven&#39;t had this problem before. What could cause this to happen?

Why am I getting &#39;Assembly &#39;*.dll&#39; must be strong signed in order to be marked as a prerequisite.&#39;?

I&#39;ve got a C# `webforms` app, that until today had been working just swimmingly.

Now today, all of a sudden, every time I try run the app, I get a file locking error: 

&gt; Unable to copy file &quot;obj\Debug\MyProject.exe&quot; to &quot;bin\Debug\MyProject.exe&quot;. The process cannot access the file &quot;bin\Debug\MyProject.exe&quot; because it is being used by another process.

Googling the error doesn&#39;t come up with anything beyond the obvious, i.e. VS thinks the file is locked.  And it is **definitely** Visual Studio itself that locks the file, because when I close VS and reopen it, the project executes fine - the first time.  When I try to run it a second time, I get the file locking error.

Closing VS and reopening every time I want to run the app is not a viable workaround!  How do I find out what&#39;s locking the file, and stop it from getting locked?

__EDIT:__ Another interesting discovery: I don&#39;t even have to run the app.  Just compiling it once causes the file locking; I cannot compile twice in a row!

This problem is specific to one project in my solution.  All other projects work fine and can be executed as many times as I like.  It&#39;s only this one project that gets itself locked up.     

Build error: &quot;The process cannot access the file because it is being used by another process&quot;

I looked in many questions about cookies but I didn&#39;t find an answer on my problem. I have following scenario:

A user creates a login on *example.com* and should get a cookie but only for the subdomain *fuu.example.com*. I generate following HTTP header part:

    Set-Cookie: name=TestUser; Domain=fuu.example.com; Path=/; secure; HttpOnly 

But when I make a request to *https://fuu.example.com*, the cookie will be not added to the request. I wonder if it is possible that *example.com* sets a cookie for `fuu.example.com`. I know that it is possible that *example.com* set a cookie for `.example.com` also for all subdomains for *example.com* but that&#39;s not what I want. 

How do I set a cookie for a subdomain? I am not seeing the cookie in a request to the subdomain.

Domain set cookie for subdomain

For my authentication process I create a unique token when a user logs in and put that into a cookie which is used for authentication.

So I would send something like this from the server:

    Set-Cookie: token=$2a$12$T94df7ArHkpkX7RGYndcq.fKU.oRlkVLOkCBNrMilaSWnTcWtCfJC; path=/;

Which works on all browsers. Then to delete a cookie I send a similar cookie with the `expires` field set for January 1st 1970

    Set-Cookie: token=$2a$12$T94df7ArHkpkX7RGYndcq.fKU.oRlkVLOkCBNrMilaSWnTcWtCfJC; path=/; expires=Thu, Jan 01 1970 00:00:00 UTC; 

And that works fine on Firefox but doesn&#39;t delete the cookie on IE or Safari.

So what is the best way to delete a cookie (without JavaScript preferably)? The set-the-expires-in-the-past method seems bulky. And also why does this work in FF but not in IE or Safari?


  [1]: http://www.mindrot.org/projects/py-bcrypt/

Correct way to delete cookies server-side

I use an [Android WebView for Twitter OAuth][1]: Twitter asks the user to log in and authorize the application, I retrieve the access token and persist it in my application.

I have no need (and do not) store the user password, but the WebView keeps Twitter&#39;s cookies around, and it also asks the user if he wants it to remember the password. As a result of this, even after the de-authorizes the application via his Twitter account page, and my application destroys the access tokens, the next time the WebView is opened, it is probably still logged in, and even if not, it has the password box already filled.

How can I force WebView to not ask to remember passwords, and to not persist session cookies?
If that is not possible, can I delete all its stored state (except maybe the image cache)?


  [1]: https://github.com/sugree/twitter-android-sdk/blob/master/twitter/src/com/sugree/twitter/TwDialog.java

Make Android WebView not store cookies or passwords

Using [Express.js][1], sessions are dead simple. I&#39;m curious how they actually work though.

Does it store some cookie on the client? If so, where can I find that cookie? If required, how do I decode it?

I basically want to be able to see if a user is logged in, even when the user is not actually on the site at the time (like how facebook knows you&#39;re logged in when you&#39;re on other sites). But I suppose to understand that I should first understand how sessions work.

  [1]: https://en.wikipedia.org/wiki/Express.js


How do sessions work in Express.js with Node.js?

**What is the shortest, accurate, and cross-browser compatible method for reading a cookie in JavaScript?** 

Very often, while building stand-alone scripts (where I can&#39;t have any outside dependencies), I find myself adding a function for reading cookies, and usually fall-back on the [QuirksMode.org `readCookie()`][1] method (280 bytes, 216 minified.)

    function readCookie(name) {
    	var nameEQ = name + &quot;=&quot;;
    	var ca = document.cookie.split(&#39;;&#39;);
    	for(var i=0;i &lt; ca.length;i++) {
    		var c = ca[i];
    		while (c.charAt(0)==&#39; &#39;) c = c.substring(1,c.length);
    		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    	}
    	return null;
    }
It does the job, but its ugly, and adds quite a bit of bloat each time. 

The method that [jQuery.cookie][2] uses something like this (modified, 165 bytes, 125 minified):

    function read_cookie(key)
    {
    	var result;
    	return (result = new RegExp(&#39;(?:^|; )&#39; + encodeURIComponent(key) + &#39;=([^;]*)&#39;).exec(document.cookie)) ? (result[1]) : null;
    }

**Note** this is not a &#39;Code Golf&#39; competition: I&#39;m legitimately interested in reducing the size of my readCookie function, and in ensuring the solution I have is valid. 


  [1]: http://www.quirksmode.org/js/cookies.html
  [2]: https://github.com/carhartl/jquery-cookie/blob/master/jquery.cookie.js

What is the shortest function for reading a cookie by name in JavaScript?

I am creating an MVC 3 web application. I want to use Data Annotations on my entity class and then use unobtrusive client side validation before making a post back to the server. This works fine when making a regular post. I get validation and the validation summary if any of the fields are not valid. However, I want to post back the information via ajax and json. How can I &#39;manually&#39; validate the form on the client side first then make my ajax post back to the server. Below is a summarized version of my code.

  

      public class Customer
        {
            [Required(ErrorMessage = &quot;The customer&#39;s first name is required.&quot;)]
            public string FirstName { get; set; }
    
            [Required(ErrorMessage = &quot;The customer&#39;s last name is required.&quot;)]
            public string LastName { get; set; }
        }
    
    
    
        &lt;% using (Html.BeginForm()) { %&gt;
        
        &lt;%: Html.LabelFor(model =&gt; model.FirstName, &quot;First Name&quot;)%&gt;
        &lt;%: Html.TextBoxFor(model =&gt; model.FirstName, new { @class = &quot;TextBox&quot;, id = &quot;Customer.FirstName&quot; })%&gt;
        &lt;%: Html.ValidationMessageFor(model =&gt; model.FirstName, &quot;*&quot;)%&gt;
        
        &lt;%: Html.LabelFor(model =&gt; model.LastName, &quot;Last Name&quot;)%&gt;
        &lt;%: Html.TextBoxFor(model =&gt; model.LastName, new { @class = &quot;TextBox&quot;, id = &quot;Customer.LastName&quot; })%&gt;
        &lt;%: Html.ValidationMessageFor(model =&gt; model.LastName, &quot;*&quot;)%&gt;
        
        &lt;div id=&quot;CustomerEditSave&quot; class=&quot;Button CustomerEditButtons&quot; style=&quot;margin-right:40px;&quot;&gt;
           &lt;a href=&quot;#&quot;&gt;Save&lt;/a&gt;
        &lt;/div&gt;
        
        &lt;%: Html.ValidationSummary(true) %&gt;
        
        &lt;% } %&gt;


I have tried this code but it only validates the first name and does not display the validation summary.

        $(&quot;#CustomerEditSave&quot;).click(function () {
            $(form).validate();
            //Ajax call here
        });


Call MVC 3 Client Side Validation Manually for ajax posts

I have the following viewmodel definition

    public class AccessRequestViewModel
    {
        public Request Request { get; private set; }
        public SelectList Buildings { get; private set; }
        public List&lt;Person&gt; Persons { get; private set; }
    }

So in my application there must be at least 1 person for an access request.  What approach might you use to validate? I don&#39;t want this validation to happen in my controller which would be simple to do. Is the only choice a custom validation attribute?

&lt;strong&gt;Edit:&lt;/strong&gt; Currently performing this validation with FluentValidation (nice library!)

	RuleFor(vm =&gt; vm.Persons)
					.Must((vm, person) =&gt; person.Count &gt; 0)
					.WithMessage(&quot;At least one person is required&quot;);

ViewModel validation for a List

How do I define a method in Razor?

I created a new MVC3 project, hit F5, saw the sample page.

Then I used NuGet to get the [Ninject.MVC extension][1]. I modified my global.asax according to the Ninject documentation, [How To Setup an MVC3 Application][2]: 

    public class MvcApplication : NinjectHttpApplication
    {
       public static void RegisterGlobalFilters(GlobalFilterCollection filters)
       {
           filters.Add(new HandleErrorAttribute());
       }
     
       public static void RegisterRoutes(RouteCollection routes)
       {
           routes.IgnoreRoute(&quot;{resource}.axd/{*pathInfo}&quot;);
     
           routes.MapRoute(
               &quot;Default&quot;, // Route name
               &quot;{controller}/{action}/{id}&quot;, // URL with parameters
               new { controller = &quot;Home&quot;, action = &quot;Index&quot;, 
                   id = UrlParameter.Optional });
       }
     
       protected override IKernel CreateKernel()
       {
           var kernel = new StandardKernel();
           kernel.Load(Assembly.GetExecutingAssembly());
           return kernel;
       }
     
       protected override void OnApplicationStarted()
       {
           base.OnApplicationStarted();
     
           AreaRegistration.RegisterAllAreas();
           RegisterGlobalFilters(GlobalFilters.Filters);
           RegisterRoutes(RouteTable.Routes);
       }
    }

Now when I run the app, I get the yellow screen of death with the following exception:

&gt; InvalidOperationException - Sequence contains no elements.
&gt;
&gt; at System.Linq.Enumerable.Single(...)
&gt; 
&gt; at Ninject.Web.Mvc.Bootstrapper.Initialize(...)
&gt; line 67.

And sure enough, [line 67 of that file][3] calls .Single(), thus throwing the exception.

What am I doing wrong?


  [1]: https://github.com/ninject/ninject.web.mvc
  [2]: https://github.com/ninject/ninject.web.mvc/wiki/Setting-up-an-MVC3-application
  [3]: https://github.com/ninject/ninject.web.mvc/blob/master/mvc3/src/Ninject.Web.Mvc/Bootstrapper.cs#L67





Ninject + MVC3 = InvalidOperationException: Sequence contains no elements

I would like to have 2 separate Layouts in my application. Let&#39;s say one is for the Public section of the website and the other is for the Member side.

For simplicity, let&#39;s say all the logic for each of these sites is wrapped neatly into 2 distinct controllers.

 - PublicController
 - StaffController

And that they each have a corresponding Layout for all the View under each.

 - _PublicLayout.cshtml
 - _StaffLayout.cshtml

How do I use the _ViewStart.cshtml file to specify that all Views / Actions under &quot;Public&quot; use the PublicLayout and everything under &quot;Staff&quot; uses the StaffLayout?


Content Type	Original Author	Original Content on Stackoverflow
Question	David	View Question on Stackoverflow
Solution 1 - C#	Metro Smurf	View Answer on Stackoverflow
Solution 2 - C#	KeithS	View Answer on Stackoverflow
Solution 3 - C#	Alex	View Answer on Stackoverflow

How do you clear cookies using asp.net mvc 3 and c#?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Describe the SVN symbols

Problem setting exif data for an image

Attributions