Major new features are,

&gt; 1. AttributeRouting
&gt; 2. OWIN self host
&gt; 3. IHttpActionResult
&gt; 4. CORS
&gt; 5. HttpRequestContext

I had the same question and found simple article about this, [here][1]. 


  [1]: http://www.strathweb.com/2013/10/asp-net-web-api-2-is-out-overview-of-features/

In addition to the features mentioned by [iJay][1]

6. Testability

7. ODATA Improvements

8. Filter Overrides

9. ByteRangeStreamContent

We can differentiate web api and web api2 by using above features.


  [1]: https://stackoverflow.com/a/29790819/685

WebAPI and WebAPI 2 

Actually WebAPI 2.0 is enhanced feature of WebApi there is no difference between this two. 
In version 2.0, the Web API framework has been enhanced to support the following features:

 - IHttpActionResult return type
 - A new Routing Attribute
 - Support for Cross-Origin requests using CORS
 - Securing ASP.NET Web API using OAuth 2.0
 - Support for $expand, $select in OData Service

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using Facebook;
    using Newtonsoft.Json;
    
    namespace facebook
    {
        class Program
        {
            static void Main(string[] args)
            {
                var client = new FacebookClient(acc_ess);
                dynamic result = client.Get(&quot;fql&quot;, new { q = &quot;select target_id,target_type from connection where source_id = me()&quot;});
                string jsonstring = JsonConvert.SerializeObject(result);
    
                //jsonstring {&quot;data&quot;:[{&quot;target_id&quot;:9503123,&quot;target_type&quot;:&quot;user&quot;}]}
                List&lt;RootObject&gt; datalist = JsonConvert.DeserializeObject&lt;List&lt;RootObject&gt;&gt;(jsonstring);
            }
            
            public class Datum
            {
                public Int64 target_id { get; set; }
                public string target_type { get; set; }
            }
    
            public class RootObject
            {          
                public List&lt;Datum&gt; data { get; set; }
            }
        }
    }

&gt; Cannot deserialize the current JSON object (e.g. {&quot;name&quot;:&quot;value&quot;})
&gt; into type
&gt; &#39;System.Collections.Generic.List`1[facebook.Program+RootObject]&#39;
&gt; because the type requires a JSON array (e.g. [1,2,3]) to deserialize
&gt; correctly. To fix this error either change the JSON to a JSON array
&gt; (e.g. [1,2,3]) or change the deserialized type so that it is a normal
&gt; .NET type (e.g. not a primitive type like integer, not a collection
&gt; type like an array or List&lt;T&gt;) that can be


I looked at other posts.

My json looks like this:

    {&quot;data&quot;:[{&quot;target_id&quot;:9503123,&quot;target_type&quot;:&quot;user&quot;}]}


Cannot deserialize the current JSON object (e.g. {&quot;name&quot;:&quot;value&quot;}) into type &#39;System.Collections.Generic.List`1

I have a `matplotlib` plot generated with the following code:


    import matplotlib.pyplot as pyplot

    Fig, ax = pyplot.subplots()
    for i, (mark, color) in enumerate(zip(
        [&#39;s&#39;, &#39;o&#39;, &#39;D&#39;, &#39;v&#39;], [&#39;r&#39;, &#39;g&#39;, &#39;b&#39;, &#39;purple&#39;])):
        ax.plot(i+1, i+1, color=color,
                marker=mark,
                markerfacecolor=&#39;None&#39;,
                markeredgecolor=color,
                label=i)

    ax.set_xlim(0,5)
    ax.set_ylim(0,5)
    ax.legend()

with this as the generated figure:
![matplotlib generated figure][1]

I don&#39;t like the lines through the markers in the legend. How can I get rid of them?


  [1]: http://i.stack.imgur.com/RzznT.png

Remove line through marker in matplotlib legend

What are the MAIN differences (things I should be concerned about) between WepApi and WepApi2 that now ships with Visual Studio 2013?

What are the differences between WebAPI and WebAPI 2

<p>What are the MAIN differences (things I should be concerned about) between WepApi and WepApi2 that now ships with Visual Studio 2013?</p>


Which C# XML documentation comment tag is used for the literals `true`, `false` and `null`?

In Microsoft&#39;s own documentation, these literals appear in **bold text**. For example, the documentation for the property [ArrayList.IsFixedSize][1] appears as:

&gt; **true** if the [ArrayList][2] has a fixed size; otherwise, **false**. The default is **false**.

None of [Microsoft&#39;s Recommended Tags][3] seem to apply to this situation. The best fit appears to be [&amp;lt;c&amp;gt;][4], however `&lt;c&gt;true&lt;/c&gt;` appears as `true` when the documentation is rendered by [Doxygen][5].

However, using `&lt;b&gt;true&lt;/b&gt;` with Doxygen yielded bold text as I surmised that it might. But that leaves me wondering about **the portability of using standard HTML tags** with other documentation generation tools such as [Sandcastle][6] and [GhostDoc][7].


  [1]: http://msdn.microsoft.com/en-us/library/system.collections.arraylist.isfixedsize%28v=vs.110%29.aspx
  [2]: http://msdn.microsoft.com/en-us/library/System.Collections.ArrayList%28v=vs.110%29.aspx
  [3]: http://msdn.microsoft.com/en-us/library/5ast78ax.aspx
  [4]: http://msdn.microsoft.com/en-us/library/te6h7cxs%28v=vs.120%29.aspx
  [5]: http://www.doxygen.nl/
  [6]: http://shfb.codeplex.com/
  [7]: http://www.roland-weigelt.de/ghostdoc/

Which C# XML documentation comment tag is used for &#39;true&#39;, &#39;false&#39; and &#39;null&#39;?

How do you convert an image from a path on the user&#39;s computer to a base64 string in C#?

For example, I have the path to the image (in the format `C:/image/1.gif`) and would like to have a data URI like `data:image/gif;base64,/9j/4AAQSkZJRgABAgEAYABgAAD..` representing the `1.gif` image returned.

Convert an image (selected by path) to base64 string

**Problem:**

I have a text file of around **120,000** users (strings) which I would like to store in a collection and later to perform a search on that collection.

The search method will occur every time the user change the text of a `TextBox` and the result should be the strings that ***contain*** the text in `TextBox`.

I don&#39;t have to change the list, just pull the results and put them in a `ListBox`.

**What I&#39;ve tried so far:**

I tried with two different collections/containers, which I&#39;m dumping the string entries from an external text file (once, of course):

 1. `List&lt;string&gt; allUsers;`
 2. `HashSet&lt;string&gt; allUsers;`

With the following [LINQ][1] query:

`allUsers.Where(item =&gt; item.Contains(textBox_search.Text)).ToList();`

My search event (fires when user change the search text):

    private void textBox_search_TextChanged(object sender, EventArgs e)
    {
        if (textBox_search.Text.Length &gt; 2)
        {
            listBox_choices.DataSource = allUsers.Where(item =&gt; item.Contains(textBox_search.Text)).ToList();
        }
        else
        {
            listBox_choices.DataSource = null;
        }
    }

**Results:**

Both gave me a poor response time (around 1-3 seconds between each key press).

**Question:**

Where do you think my bottleneck is? The collection I&#39;ve used? The search method? Both?

How can I get better performance and more fluent functionality?

  [1]: http://en.wikipedia.org/wiki/Language_Integrated_Query


Fastest way to search in a string collection

I need to create a POST method in WebApi so I can send data from application to WebApi method. I&#39;m not able to get header value.

Here I have added header values in the application:

     using (var client = new WebClient())
            {
                // Set the header so it knows we are sending JSON.
                client.Headers[HttpRequestHeader.ContentType] = &quot;application/json&quot;;

                client.Headers.Add(&quot;Custom&quot;, &quot;sample&quot;);
                // Make the request
                var response = client.UploadString(url, jsonObj);
            }
Following the WebApi post method:

     public string Postsam([FromBody]object jsonData)
        {
            HttpRequestMessage re = new HttpRequestMessage();
            var headers = re.Headers;

            if (headers.Contains(&quot;Custom&quot;))
            {
                string token = headers.GetValues(&quot;Custom&quot;).First();
            }
        }

What is the correct method for getting header values?

Thanks.

How to add and get Header values in WebApi

I saw a loop which I&#39;ve never seen before:

    for (int i = 0; i &lt; (1 &lt;&lt; list.Count); i++)

I can&#39;t understand what `(1 &lt;&lt; list.Count)` means, maybe someone could explain me this?

What do two left angle brackets mean?

I have a window with the following appearance:

![enter image description here][1]

What I would like, however, is if the `Button` controls (the gray ones with text in the middle) in the `Window`&#39;s main `Grid` had an opacity of 1, totally opaque.  As I inherited this project the opacity was set to 0.75 at the top level, inside the opening `Window` tag.  Now as I understand this will automatically enforce that on all children and that said children cannot override.

How then can I accomplish the transparent background but opaque buttons?  The only way I have found so far (as a relative novice in WPF) is to have two separate Windows, one which is the transparent background, and the other has no background but contains the opaque controls.  This is terribly hacky though and I want to avoid it if I can.

I can supply code if requested, but it is really as simple as a `Window` with windowstyle=none and opacity .75 containing a `Grid`, which contains some very basic `Button` etc controls.

Has anyone built such a `Window` before or otherwise have insight into generating one?  Thanks.


  [1]: http://i.stack.imgur.com/7Jegp.png

WPF Window with transparent background containing opaque controls

I am encrypting the user&#39;s input for generating a string for password. But a line of code gives different results in different versions of the framework. Partial code with value of key pressed by user:

Key pressed: 1. Variable `ascii` is 49. Value of &#39;e&#39; and &#39;n&#39; after some calculation:

    e = 103, 
    n = 143,

    Math.Pow(ascii, e) % n

Result of above code:

- In .NET 3.5 (C#)

        Math.Pow(ascii, e) % n

 gives `9.0`.

- In .NET 4 (C#)

        Math.Pow(ascii, e) % n

 gives `77.0`.

`Math.Pow()` gives the correct (same) result in both versions.

What is the cause, and is there a solution?


The modulo operator (%) gives a different result for different .NET versions in C#

How can I split a C# string based on the first occurrence of the specified character?
Suppose I have a string with value: 
```
101,a,b,c,d
```
I want to split it as 
```
101
``` 

```
a,b,c,d
```
That is by the first occurrence of comma character.

Split string based on the first occurrence of the character

 Please have a look at the following code-

    static void Main(string[] args)
    {
        // Get the task.
        var task = Task.Factory.StartNew&lt;int&gt;(() =&gt; { return div(32, 0); });

        // For error handling.
        task.ContinueWith(t =&gt; { Console.WriteLine(t.Exception.Message); }, 
            TaskContinuationOptions.OnlyOnFaulted);

        // If it succeeded.
        task.ContinueWith(t =&gt; { Console.WriteLine(t.Result); }, 
            TaskContinuationOptions.OnlyOnRanToCompletion);
        Console.ReadKey();
        Console.WriteLine(&quot;Hello&quot;);
    }

    private static int div(int x, int y)
    {
        if (y == 0)
        {
            throw new ArgumentException(&quot;y&quot;);
        }
        return x / y;
    }

If I execute the code in release mode, The output is &quot;One or more errors occurred&quot; and once I hit the &quot;Enter key, &quot;Hello&quot; is also getting displayed. If I run the code in debug mode, the output is same as release mode. But when debugging in IDE, A IDE exception message (&quot;Unhandled exception in user code&quot; ) appears when the control executes the line 

    throw new ArgumentException(&quot;y&quot;); 

If I continue from there on, the program does not crash and displays the same output as release mode. Is this proper way to handle exception?
            

Proper way of handling exception in task continuewith

How do we get the current user, within an secure ApiController action, without passing the userName or userId as a parameter? 

We assume that this is available, because we are within a secure action. Being in a secure action means that the user has already authenticated and the request has her bearer token. Given that WebApi has authorized the user, there may be a built in way to access the userId, without having to pass it as an action parameter.



Get the current user, within an ApiController action, without passing the userID as a parameter

I am using latest `web api`.

I do annotate *some* controllers with 3 different filter attributes.

    1 [Authorize]
    2 [RessourceOwnerAttribute derived from AuthorizationFilterAttribute]
    3 [InvalidModelStateAttribute derived from ActionFilterAttribute]

I can not be sure that the filters run in the order they are declared from top to down.

How do I define the order of execution in `web api 2.1` ?

https://aspnetwebstack.codeplex.com/workitem/1065#

http://aspnet.uservoice.com/forums/147201-asp-net-web-api/suggestions/3346720-execution-order-of-mvc4-webapi-action-filters

Do I still have to fix that for myself ??

Order of execution with multiple filters in web api

I have been developing with WebApi and have moved on to WebApi2 where Microsoft has introduced a new `IHttpActionResult` Interface that seems to recommended to be used over returning a `HttpResponseMessage`. I am confused on the advantages of this new Interface. It seems to mainly just provide a **SLIGHTLY** easier way to create a `HttpResponseMessage`. 

I would make the argument that this is &quot;abstraction for the sake of abstraction&quot;. Am I missing something? What is the real world advantages I get from using this new Interface besides maybe saving a line of code?

**Old way** (WebApi):

    public HttpResponseMessage Delete(int id)
    {
        var status = _Repository.DeleteCustomer(id);
        if (status)
        {
            return new HttpResponseMessage(HttpStatusCode.OK);
        }
        else
        {
            throw new HttpResponseException(HttpStatusCode.NotFound);
        }
    }

**New Way** (WebApi2):

    public IHttpActionResult Delete(int id)
    {
        var status = _Repository.DeleteCustomer(id);
        if (status)
        {
            //return new HttpResponseMessage(HttpStatusCode.OK);
            return Ok();
        }
        else
        {
            //throw new HttpResponseException(HttpStatusCode.NotFound);
            return NotFound();
        }
    }

Why should I use IHttpActionResult instead of HttpResponseMessage?

The [documentation](http://www.asp.net/web-api/overview/creating-web-apis/creating-api-help-pages) for enabling XmlDoc integration into your Web Api projects appears to only handle situations where all of your API types are part of your WebApi project.  In particular, it discusses how to reroute the XML documentation to `App_Data/XmlDocument.xml` and uncommenting a line in your config that will consume that file.  This implicitly only allows for one project&#39;s documentation file.  

However, in my setup I have my request and response types defined in a common &quot;Models&quot; project.  This means that if I have an endpoint defined such as:

    [Route(&quot;auth/openid/login&quot;)]
    public async Task&lt;AuthenticationResponse&gt; Login(OpenIdLoginRequest request) { ... }

Where `OpenIdLoginRequest` is defined in a separate C# project like so:

    public class OpenIdLoginRequest
    {
        /// &lt;summary&gt;
        /// Represents the OpenId provider that authenticated the user. (i.e. Facebook, Google, etc.)
        /// &lt;/summary&gt;
        [Required]
        public string Provider { get; set; }

        ...
    }


Despite the XML doccomments, the properties of the `request` parameter contain no documentation when you view the endpoint-specific help page (i.e. `http://localhost/Help/Api/POST-auth-openid-login`).  

How can I make it so that types in subprojects with XML documentation are surfaced in the Web API XML documentation?


Content Type	Original Author	Original Content on Stackoverflow
Question	Jason Roell	View Question on Stackoverflow
Solution 1 - C#	iJay	View Answer on Stackoverflow
Solution 2 - C#	Edukondalu Thaviti	View Answer on Stackoverflow
Solution 3 - C#	A.Bhagat	View Answer on Stackoverflow

What are the differences between WebAPI and WebAPI 2

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Remove line through marker in matplotlib legend

Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1

Attributions