That&#39;s not as crazy as you think. In fact, you can achieve this using [AppDomains](https://msdn.microsoft.com/en-us/library/2bh4z9hs.aspx).

Each [`AppDomain`](https://msdn.microsoft.com/en-us/library/system.appdomain.aspx) has its own storage location for static variables. So you can just create a second AppDomain in your process, and communicate between them using an object that inherits from `MarshalByRefObject` like in [this MSDN example](https://msdn.microsoft.com/en-us/library/system.appdomain.aspx#exampleToggle).

While [Lucas&#39; suggestion](https://stackoverflow.com/a/28235493/146622) on AppDomains would work, alternatively you could create this effect using generics, as a class with different generic type arguments is treated as a different class, and therefore has its own static fields.

	public class SomeClass&lt;T&gt;
	{
		public static string SomeField;
	}
	
Then:

	SomeClass&lt;int&gt;.SomeField = &quot;A&quot;;
	SomeClass&lt;string&gt;.SomeField = &quot;B&quot;;
	
	Console.WriteLine(SomeClass&lt;int&gt;.SomeField);	// A
	Console.WriteLine(SomeClass&lt;string&gt;.SomeField);	// B

For example, the `SomeClass&lt;int&gt;` would be set in the library, whereas the `SomeClass&lt;string&gt;` would be your copy. Of course this would only work if you could change the library, or the library already used generics.

Both suggestions should work, but they are all terrific concerning architecture.

I a not aware about the context, but in your case is it possible to just create an aggregation class with a new property that is not static and just have two instances.
This sound like a better way for me.

Everytime I have smart code, an alert starts in my head. Smart code is always too clever for a developer.




I don&#39;t understand why

    SELECT UUID();
    
Returns something like:

    3f06af63-a93c-11e4-9797-00505690773f

But if I insert it into a binary(16) field (the UUID() function) with for instance a BEFORE INSERT trigger and run a select, it returns something like:

    0782ef48-a439-11

Note that these two UUIDs are not the same data.

I realize binary and an UUID string doesn&#39;t look identical, but shouldn&#39;t the selected data at least be just as long? Otherwise how can it possibly be equally likely to be unique?

Is it better to store it as char(36)? I just need it to be unique to prevent duplicate inserts. It is never selected or used for joins.

EDIT:

before trigger would be like:

    BEGIN
    
    if NEW.UUID IS NULL THEN
    
    NEW.UUID = UUID();
    
    END IF
    
    END

Inserting and selecting UUIDs as binary(16)

I&#39;m having a problem in understanding why the following code doesn&#39;t work.

I have following project structure:

    @Component(modules = CCModule.class) 
    public interface CComponent {
        XXX getXXX();
    }

where 

    @Module
    public class CCModule {

        @Provides @Singleton
        public XXX provide XXX(){
            return new XXX();
        }
    }

and 

    @Component(dependencies = CComponent.class, modules = AAModule.class) 
    public interface AComponent {
        YYY getYYY();
    }

where

    class YYY {
       @Inject
       public YYY(XXX xxx) {
           ...
       }
    }

I initialize everything as:

    CComponent c_component = Dagger_CComponent.builder().cCModule(new CCModule()).build();

    AComponent a_component = Dagger_AComponent.builder()
            .cComponent(c_component)
            .aAModule(new AAModule())
            .build();

Once compilation takes place i get the following error:

&gt; Error:(11, 1) error:
&gt; com.test.CComponent (unscoped) may not
&gt; reference scoped bindings: @Provides @Singleton
&gt; com.test.XXX
&gt; com.test.CCModule.provideXXX()

What I&#39;m aiming for is to have one component inherit bindings from other components to have the same references to an objects (singletons).

Problems with singletons when using component dependencies

I have a library that has a static field inside. I want to create an app and reference this library so I&#39;d have two instances of this static field. .Net runtime does not allow to reference the same library twice, but I wonder is it possible to overcome this limitation?

I&#39;m not allowed to change the library, but I can copy/rename it.

Is static context always single in C#?

<p>I have a library that has a static field inside. I want to create an app and reference this library so I'd have two instances of this static field. .Net runtime does not allow to reference the same library twice, but I wonder is it possible to overcome this limitation?</p>
<p>I'm not allowed to change the library, but I can copy/rename it.</p>


I just noticed that using `{}` instead of `()` gives the same results when constructing an object.

    class Customer
    {
        public string name;
        public string ID {get; set;}
    }

    static void Main()
    {  
        Customer c1= new Customer{}; //Is this a constructor? 
        Customer c2= new Customer();
        
        //what is the concept behind the ability to assign values for properties 
        //and fields inside the {} and is not allowable to do it inside () 
        //without defining a constructor:
        
        Customer c3= new Customer{name= &quot;John&quot;, ID=&quot;ABC&quot;};
    }

Does `{}` act like `()` when creating a new object in C#?

Does { } act like ( ) when creating a new object in C#?

Default ASP.NET Core web project contain such lines in `Startup.cs`:

    if (string.Equals(env.EnvironmentName, &quot;Development&quot;, StringComparison.OrdinalIgnoreCase))
	{
		app.UseBrowserLink();
		app.UseDeveloperExceptionPage(ErrorPageOptions.ShowAll);
	}
	else
	{
		app.UseExceptionHandler(&quot;/Home/Error&quot;);
	}

As I understand, the EnvironmentName is a new way to handle Dev/Production environment. But it doesn&#39;t changes on Release build configuration. So what is the way to set a different `EnvironmentName`?

I can imagine that it should be set in &quot;Commands&quot; as a parameter for server.

How to set Environment Name (IHostingEnvironment.EnvironmentName)?

*UPDATE* The purpose of this question is to get a simple answer about `Task.Run()` and deadlocking.  I very much understand the theoretical reasoning for not mixing async and sync, and I take them to heart.  I&#39;m not above learning new things from others; I seek to do that whenever I can.  There&#39;s just times when all a guy needs is a technical answer...

I have a `Dispose()` method that needs to call an async method.  Since 95% of my code is async, refactoring isn&#39;t the best choice.  Having an `IAsyncDisposable` (among other features) that&#39;s supported by the framework would be ideal, but we&#39;re not there yet.  So in the mean time, I need to find a reliable way to call async methods from a synchronous method without deadlocking.

I&#39;d prefer _not_ to use `ConfigureAwait(false)` because that leaves the responsibility scattered all throughout my code for the callee to behave a certain way just in case the caller is synchronous.  I&#39;d prefer to do something in the synchronous method since it&#39;s the deviant bugger.

After reading Stephen Cleary&#39;s comment in another question that `Task.Run()` always schedules on the thread pool even async methods, it made me think.

In .NET 4.5 in ASP.NET or any other synchronization context that schedules tasks to the current thread / same thread, if I have an asynchronous method:

    private async Task MyAsyncMethod()
    {
        ...
    }

And I want to call it from a synchronous method, can I just use `Task.Run()` with `Wait()` to avoid deadlocks since it queues the async method the the thread pool?

    private void MySynchronousMethodLikeDisposeForExample()
    {
        // MyAsyncMethod will get queued to the thread pool 
        // so it shouldn&#39;t deadlock with the Wait() ??
        Task.Run((Func&lt;Task&gt;)MyAsyncMethod).Wait();
    }



Use Task.Run() in synchronous method to avoid deadlock waiting on async method?

I have a requirement to execute a script in document.ready function if viewbag property is null or not exists. Below is the code I wrote to check if viewbag property not exists.

I used recommned approached where you `@ViewBag.Property!=null` but when I do that I get an error saying name property does not exist in current context,


    @section scripts {
   
    @if ((bool)ViewData.ContainsKey(&quot;FormSubmitFlag&quot;) == false)
    {
        &lt;script type=&quot;text/javascript&quot;&gt;
            $(document).ready(function () {

                var pageVisitCount = sessionStorage.getItem(&quot;personalDetailsVisitCount&quot;);
                if (pageVisitCount == null) {
                    $(&quot;#personal-details-form&quot;).trigger(&#39;reset&#39;);
                    sessionStorage.setItem(&quot;personalDetailsVisitCount&quot;, &quot;1&quot;);
                }
                else {
                    var validator = $(&quot;#personal-details-form&quot;).validate();
                    validator.form();
                    cat.personaldetails.validate();
                }
            });
        &lt;/script&gt;
    }
     
    }


Thank you

How to check if ViewBag property is null or not exists

How to pass a value to razor variable from javascript variable, is it possible asp.net mvc razor view engine?

    @{
        int a = 0;
    }

    &lt;script&gt;
        var b = ...
        @a = b;
    &lt;/script&gt;

How to pass a value to razor variable from javascript variable?

What is the default security protocol for communicating with servers that support up to `TLS 1.2`? Will `.NET` by default, choose the highest security protocol supported on the server side or do I have to explicitly add this line of code:

    System.Net.ServicePointManager.SecurityProtocol = 
    SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;

Is there a way to change this default, besides a code change?

Lastly, does `.NET 4.0` only support up to `TLS 1.0`? i.e. I have to upgrade client projects to 4.5 to support `TLS 1.2`.

My motivation is to remove support for `SSLv3` on the client side even if server supports it (I already have a powershell script to disable this in the machine registry) and to support the highest TLS protocol that the server supports.

**Update:**
Looking at the `ServicePointManager` class in `.NET 4.0` I see no enumerated values for `TLS 1.0` and `1.1`. In both `.NET 4.0/4.5`, the default is `SecurityProtocolType.Tls|SecurityProtocolType.Ssl3`. Hopefully this default won&#39;t break by disabling `SSLv3` in the registry.

However, I&#39;ve decided I have to upgrade all apps to `.NET 4.5` and to explicitly add `SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;` anyway to all bootstrapping code of all applications.

This will make outbound requests to various apis and services to not downgrade to `SSLv3` and should select the highest level of `TLS`.

Does this approach sound reasonable or overkill? I have many applications to update, and I want to future proof them since I hear even `TLS 1.0` may be deprecated in the near future by some providers.

As a client making outbound requests to APIs, does disabling SSL3 in the registry even have an effect in the .NET framework? I see by default, TLS 1.1 and 1.2 are not enabled, do we have to enable it via the registry? RE http://support.microsoft.com/kb/245030. 

After a bit of investigation, I believe the registry settings will have no affect since they apply to IIS (server subkey) and browsers (client subkey).

Sorry this post turned into multiple questions, followed up with &quot;maybe&quot; answers.

Default SecurityProtocol in .NET 4.5

When talking about identity in .NET we have the idea of [Principal](http://msdn.microsoft.com/en-us/library/System.Security.Principal). There&#39;s the interface [`IPrincipal`](http://msdn.microsoft.com/en-us/library/system.security.principal.iprincipal) and together with it the implementation [`ClaimsPrincipal`](http://msdn.microsoft.com/en-us/library/system.security.claims.claimsprincipal). We can even access one instance of an implementation of that interface any time using [`Thread.CurrentPrincipal`](http://msdn.microsoft.com/en-us/library/system.threading.thread.currentprincipal).

Now, I never understood what this principal really is. Indeed, at first I thought it was something representing the identity of the current user. But it&#39;s not, in fact there&#39;s another interface [`IIdentity`](http://msdn.microsoft.com/en-us/library/system.security.principal.iidentity) together with implementation [`ClaimsIdentity`](http://msdn.microsoft.com/en-us/library/system.security.claims.claimsidentity) for that. Searching a little I found the following on MSDN:

&gt; A principal object represents the security context of the user on whose behalf the code is running, including that user&#39;s identity (IIdentity) and any roles to which they belong.

But what this *security context of the user on whose behalf the code is running* really means? I think I didn&#39;t get yet what this is supposed to represent.

What is really a Principal in .NET?

**UPDATE**

Thanks for all the answers. I am on a new project and it looks like I&#39;ve finally got to the bottom of this: It looks like the following code was in fact to blame:


    public static HttpResponseMessage GetHttpSuccessResponse(object response, HttpStatusCode code = HttpStatusCode.OK)
    {
        return new HttpResponseMessage()
        {
            StatusCode = code,
            Content = response != null ? new JsonContent(response) : null
        };
    }

elsewhere...
           
    public JsonContent(object obj)
    {
        var encoded = JsonConvert.SerializeObject(obj, Newtonsoft.Json.Formatting.None, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore } );
        _value = JObject.Parse(encoded);
        
        Headers.ContentType = new MediaTypeHeaderValue(&quot;application/json&quot;);
    }

I had overlooked the innocuous looking JsonContent assuming it was WebAPI but no.

This is used _everywhere_... Can I just be the first to say, wtf? Or perhaps that should be &quot;Why are they doing this?&quot;

-----------------------------------

*original question follows*


One would have thought this would be a simple config setting, but it&#39;s eluded me for too long now.

I have looked at various solutions and answers:

https://gist.github.com/rdingwall/2012642

doesn&#39;t seem to apply to latest WebAPI version...

The following doesn&#39;t seem to work - property names are still PascalCased.


    var json = GlobalConfiguration.Configuration.Formatters.JsonFormatter;

    json.UseDataContractJsonSerializer = true;
    json.SerializerSettings.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore;

    json.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver(); 

Mayank&#39;s answer here: https://stackoverflow.com/questions/23370619/camelcase-json-webapi-sub-objects-nested-objects-child-objects seemed like an unsatisfactory but workable answer until I realised these attributes would have to be added to generated code as we are using linq2sql...

Any way to do this automatically? This &#39;nasty&#39; has plagued me for a long time now. 


Content Type	Original Author	Original Content on Stackoverflow
Question	Archeg	View Question on Stackoverflow
Solution 1 - C#	Lucas Trzesniewski	View Answer on Stackoverflow
Solution 2 - C#	Daniel A.A. Pelsmaeker	View Answer on Stackoverflow
Solution 3 - C#	Frédéric De Lène Mirouze	View Answer on Stackoverflow

Is static context always single in C#?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Problems with singletons when using component dependencies

Inserting and selecting UUIDs as binary(16)

Attributions