You could try [System.Web.Hosting.HostingEnvironment.MapPath()][1].

No HttpContext required.


  [1]: http://msdn.microsoft.com/en-us/library/system.web.hosting.hostingenvironment.mappath.aspx

Use `AppDomain.CurrentDomain.BaseDirectory` because `Context` might return null !!

When in Global.asax, use the ***context*** object:

context.Server.mappath()

Context lets you access also the session collection, the request object, the response object. Very useful when you want to log errors, for example




You could try HttpContext.Current.Server.MapPath(&quot;/&quot;) - That&#39;s how I have referenced it before in classes.

Given a list of words, how would you go about arranging them into a crossword grid?

It wouldn&#39;t have to be like a &quot;proper&quot; crossword puzzle which is symmetrical or anything like that: basically just output a starting position and direction for each word.

Algorithm to generate a crossword

How do I remove the carriage return character `(\r)` and the new line character`(\n)` from the end of a string?

Removing carriage return and new-line from the end of a string in c#

I need to use `Server.MapPath()` to combine some files path that I store in the `web.config`.

However, since `Server.MapPath()` relies on the current HttpContext (I think), I am unable to do this.  When trying to use the method, even though its &quot;available&quot;, I get the following exception:

&gt;Server operation is not available in this context.

Is there another method that can map a web root relative directory such as `~/App_Data/` to the full physical path such as `C:\inetpub\wwwroot\project\App_data\` ?

How can I use Server.MapPath() from global.asax?

I need to use <code>Server.MapPath()</code> to combine some files path that I store in the <code>web.config</code>.
However, since <code>Server.MapPath()</code> relies on the current HttpContext (I think), I am unable to do this. When trying to use the method, even though its "available", I get the following exception:
>Server operation is not available in this context.
Is there another method that can map a web root relative directory such as <code>~/App_Data/</code> to the full physical path such as <code>C:\inetpub\wwwroot\project\App_data\</code> ?

I need some help with CASE statements in linq (c#):

    osc_products.products_quantity =
          CASE 
             WHEN itempromoflag &lt;&gt; &#39;N&#39; THEN 100000
             WHEN itemcat1 IN (&#39;1&#39;,&#39;2&#39;,&#39;31&#39;) AND itemsalestatus = &#39;S&#39; THEN 100000
             WHEN itemsalestatus = &#39;O&#39; THEN 0
             ELSE cds_oeinvitem.itemqtyonhand - cds_oeinvitem.itemqtycommitted 
          END  


My start at converting to linq, (I&#39;m still learning):


&gt;     cdsDBDataContext db = new cdsDBDataContext();
      var query = from items in db.cdsItems
                  where items.ItemHandHeldFlag.Equals(&quot;Y&quot;) &amp;&amp; 
                  items.ItemQtyOnHand -  items.ItemQtyCommitted &gt; 0
      select items;


This query updates stock status from production to a commerce site.

linq case statement

Duplicate of: [How to ensure an event is only subscribed to once][1]
and [Has an event handler already been added?][2]


I have a singleton that provides some service and my classes hook into some events on it, sometimes a class is hooking twice to the event and then gets called twice.
I&#39;m looking for a classical way to prevent this from happening. somehow I need to check if I&#39;ve already hooked to this event...


  [1]: https://stackoverflow.com/questions/367523/how-to-ensure-an-event-is-only-subscribed-to-once
  [2]: https://stackoverflow.com/questions/136975/has-an-event-handler-already-been-added

C# pattern to prevent an event handler hooked twice

I am trying to change the UserAgent of the WebBrowser control in a Winforms application.

I have successfully achieved this by using the following code:

    [DllImport(&quot;urlmon.dll&quot;, CharSet = CharSet.Ansi)]
    private static extern int UrlMkSetSessionOption(
        int dwOption, string pBuffer, int dwBufferLength, int dwReserved);

    const int URLMON_OPTION_USERAGENT = 0x10000001;

    public void ChangeUserAgent()
    {
        List&lt;string&gt; userAgent = new List&lt;string&gt;();
        string ua = &quot;Googlebot/2.1 (+http://www.google.com/bot.html)&quot;;

        UrlMkSetSessionOption(URLMON_OPTION_USERAGENT, ua, ua.Length, 0);
    }

The only problem is that this only works once. When I try to run the ChangeUserAgent() method for the second time it doesn&#39;t work. It stays set to the first changed value. This is quite annoying and I&#39;ve tried everything but it just won&#39;t change more than once.

Does anyone know of a different, more flexible approach?

Thanks


Changing the user agent of the WebBrowser control

I have the following object in a list:

    public class DemoClass
    {
    	public int GroupKey { get; set; }
    	public string DemoString { get; set; }
    	public object SomeOtherProperty { get; set; }
    }

Now, I want to create following dictionary out of it:

    Dictionary&lt;int, List&lt;DemoClass&gt;&gt;

I want to group the `List&lt;DemoClass&gt;` by the property `GroupKey`, but I don&#39;t understand how this is done and some help.

After thinking a bit, I achieved the needed behaviour with:

    var groupedDemoClasses = from demoClass in mySepcialVariableWhichIsAListOfDemoClass
    							group demoClass by demoClass.GroupKey
    							into groupedDemoClass
    							select groupedDemoClass;
    var neededDictionary = groupedDemoClass.ToDictionary(gdc =&gt; gdc.Key, gdc =&gt; gdc.ToList());

but, is there a way to make this into a single statement?

Create a dictionary on a list with grouping

I found solutions for Windows Forms with AppDomain but what would be the equivalent for a WPF `Application` object?

Getting the application&#39;s directory from a WPF application

I&#39;m trying to use an ASP.NET `RangeValidator` to validate a date on a textbox. The format of the date entered on the textbox is `dd MMMM yyyy`.

How can I use the range validator to validate a valid date? If I enter **1 January 1000** as the min or max value I get an error saying value cannot be converted to type date, but if I use another format it picks up my entered text as invalid.

Below is my code:

    &lt;asp:TextBox 
        runat=&quot;server&quot; 
        ID=&quot;txtDatecompleted&quot; 
    /&gt;
    &lt;cc2:CalendarExtender
        ID=&quot;datecompletedExtender&quot; 
        runat=&quot;server&quot;
        TargetControlID=&quot;txtDatecompleted&quot;
        Format=&quot;dd MMMM yyyy&quot;
    /&gt;	
    &lt;asp:RangeValidator 
        runat=&quot;server&quot; 
        ID=&quot;RangeValidator1&quot; 
        Type=&quot;Date&quot; 
        ControlToValidate=&quot;txtDatecompleted&quot; 
        MaximumValue=&quot;9999/12/28&quot; 
        MinimumValue=&quot;1000/12/28&quot; 
        ErrorMessage=&quot;enter valid date&quot; 
        Display=&quot;None&quot;
    /&gt;
    &lt;cc2:ValidatorCalloutExtender 
        ID=&quot;RangeValidator1_ValidatorCalloutExtender&quot; 
        runat=&quot;server&quot;
        Enabled=&quot;True&quot;
        TargetControlID=&quot;RangeValidator1&quot;&gt;
    &lt;/cc2:ValidatorCalloutExtender&gt;

Date validation with ASP.NET validator

What is the difference between Session and HttpContext.Current.Session object?

Difference between Session and HttpContext.Current.Session

Is there any difference between `Server.MapPath()` and `HostingEnvironment.MapPath()`? Does `Server.MapPath()` have any advantages over `HostingEnvironment.MapPath()`?

My original problem was mapping the file path on a server when the `HttpContext` is not present and I cannot pass a `Server` variable from `Global.asax` to my method. 

I used `HostingEnvironment.MapPath()` instead since it doesn&#39;t need `HttpContext`. Are there any situations when these two methods will give different results?


What is the difference between Server.MapPath and HostingEnvironment.MapPath?

I&#39;ve programmed in both classic ASP and ASP.NET, and I see different tags inside of the markup for server side code.  

I&#39;ve recently come across a [good blog on MSDN][1] that goes over the difference between:

- `&lt;%=` (percentage together with equals sign) and 
- `&lt;%#` (percent sign and hash/pound/octothorpe) 

(`&lt;%#` is evaluated only at databind, and `&lt;%=` is evaluated at render), but I also see:

- `&lt;%$` (percent and dollar sign) and 
- `&lt;%@` (percent sign and at symbol).

I believe `&lt;%@` loads things like assemblies and perhaps `&lt;%$` loads things from config files?  I&#39;m not too sure.

I was just wondering if anyone could clarify all of this for me and possibly explain why it&#39;s important to create so many different tags that seemingly have a similar purpose?


  [1]: http://blogs.msdn.com/dancre/archive/2007/02/13/the-difference-between-lt-and-lt-in-asp-net.aspx

&lt;%$, &lt;%@, &lt;%=, &lt;%# ... what&#39;s the deal?

How to disable browser&#39;s BACK Button (across browsers)?


Disable browser&#39;s back button

I can&#39;t debug global.asax file! 

I have some codes in `Application_Start()` method but when I set a break point in the method, it is ignored! 

Is this normal?

Is it possible to debug Global.asax?

In my .Net 2.0 Asp.net WebForms app, I have my Global.asax containing the following code:

    &lt;%@ Application CodeBehind=&quot;Global.asax.cs&quot; Inherits=&quot;MyNamespace.Global&quot; Language=&quot;C#&quot; %&gt;
However when I build I get an error stating-

&gt; Could not load type &#39;MyNamespace.Global&#39;.

This seems to be because the MyNamespace namespace (defined in the code behind file Global.asax.cs) is not seen by the compiler in the Global.asax file (does not show in R# intellisence..).
This turned out to be a very hard nut to crack... any help will be appreciated!

Note: The Global.asax and the Global.asax.cs are located in the same folder.

Note2: When compiling from the vs prompt with csc it compiles o.k. 

&quot;Could not load type [Namespace].Global&quot; causing me grief

I am starting to use MVC4 Web API project, I have controller with multiple `HttpPost` methods. The Controller looks like the following:

**Controller**

    public class VTRoutingController : ApiController
    {
        [HttpPost]
        public MyResult Route(MyRequestTemplate routingRequestTemplate)
        {
            return null;
        }
    
        [HttpPost]
        public MyResult TSPRoute(MyRequestTemplate routingRequestTemplate)
        {
            return null;
        }
    }

*Here `MyRequestTemplate` represents the template class responsible for handling the Json coming through the request.* 

**Error:**

When I make a request using Fiddler for `http://localhost:52370/api/VTRouting/TSPRoute` or `http://localhost:52370/api/VTRouting/Route`  I get an error: 

&gt; Multiple actions were found that match the request

If I remove one of the above method it works fine.

**Global.asax**

I have tried modifying the default routing table in `global.asax`, but I am still getting the error, I think I have problem in defining routes in global.asax. Here is what I am doing in global.asax. 

    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.MapHttpRoute(
            name: &quot;MyTSPRoute&quot;,
            routeTemplate: &quot;api/VTRouting/TSPRoute&quot;,
            defaults: new { }
        );
    
        routes.MapHttpRoute(
            name: &quot;MyRoute&quot;,
            routeTemplate: &quot;api/VTRouting/Route&quot;,
            defaults: new { action=&quot;Route&quot; }
        );
    }

I am making the request in Fiddler using POST, passing json in RequestBody for MyRequestTemplate.

Multiple HttpPost method in Web API controller

How can i use the server.mappath method in a C# class library class ,which acts as my BusinessLayer for My ASP.NET WEbsite

Server.Mappath in C# classlibrary

I&#39;m building an ASP.NET MVC site where I&#39;m using Lucene.Net for search queries. I [asked a question here][1] about how to properly structure Lucene.Net usage in an ASP.NET MVC application and was told that the best method is to declare the my `IndexWriter` as `public static`, so that it can be re-used.

Here is some code that is at the top of my SearchController:

    public static string IndexLocation = Server.MapPath(&quot;~/lucene&quot;);
    public static Lucene.Net.Analysis.Standard.StandardAnalyzer analyzer = new Lucene.Net.Analysis.Standard.StandardAnalyzer();
    public static IndexWriter writer = new IndexWriter(IndexLocation,analyzer);

As `writer` is static, `IndexLocation` must also be static. Thus, the compiler is giving me the following error for `Server.MapPath()`:

 &gt; An object reference is required for the non-static field, method, or property &#39;System.Web.Mvc.Controller.Server.get&#39;

Is there **a way of using Server.MapPath() or something similar from a static field**? How can I fix this error?

  [1]: https://stackoverflow.com/questions/3480974/proper-structuring-of-lucene-net-usage-in-an-asp-net-mvc-site

Using Server.MapPath() inside a static field in ASP.NET MVC

What I must do to make `Server.MapPath` work?  
I have `using System.Web;` 

what else? When I type `Server` there is no quick result option (intelli-sense) for `Server`. 

Any help?

Content Type	Original Author	Original Content on Stackoverflow
Question	John B	View Question on Stackoverflow
Solution 1 - C#	Corbin March	View Answer on Stackoverflow
Solution 2 - C#	Kiran Banda	View Answer on Stackoverflow
Solution 3 - C#	tekBlues	View Answer on Stackoverflow
Solution 4 - C#	VoltaicShock	View Answer on Stackoverflow

How can I use Server.MapPath() from global.asax?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Solution 4 - C#

Removing carriage return and new-line from the end of a string in c#

Algorithm to generate a crossword

Attributions