Adding Swagger to ASP.NET Web API

Step 1: - Open Visual Studio 2015 => Go to File Menu => New => Project...

Step 2: - In the Installed Templates list, select Visual C# => Web

Step 3: - Select ASP.Net Web Application (.NET Framework) from the Web list => Type SwaggerDemo in the Name box and click OK

Step 4: - Select Empty template from ASP.NET Templates List and Check Web API check box under Add folders and core references for:

Step 5: - Right Click on Controllers folder => Add => Controller... => Select Web API Controller - Empty => Click Add => Type DefaultController in Controller Name box => Click Add

Copy Past following code in DefaultController

/// <summary>

/// I'm Action1

/// </summary>

/// <returns>I'm Action1</returns>

[HttpGet]

public HttpResponseMessage Action1()

{

    return Request.CreateResponse(HttpStatusCode.OK, "I'm Action1");

}

/// <summary>

/// I'm Action2

/// </summary>

/// <returns>I'm Action2</returns>

[HttpGet]

public HttpResponseMessage Action2()

{

    return Request.CreateResponse(HttpStatusCode.OK, "I'm Action2");

}

/// <summary>

/// I'm Action3

/// </summary>

/// <returns>I'm Action3</returns>

[HttpGet]

public HttpResponseMessage Action3()

{

    return Request.CreateResponse(HttpStatusCode.OK, "I'm Action3");

}

Step 6: - Right click on References => Click on Manage NuGet Packages... => Click on Browse => Search "Swagger" => Select "Swashbuckle" from result => Click on Install

Step 7: - Open/Expand App_Start folder => Open SwaggerConfig.cs file => Add following line to enable Xml Comments description in swagger documentation

c.IncludeXmlComments(String.Format(@"{0}\bin\SwaggerDemo.XML", AppDomain.CurrentDomain.BaseDirectory));

Step 8: - Right Click on Project Root folder => Click on Properties => Select "Build" => Under Output section Check checkbox "XML documentation file:" => Press Ctrl + S to save file

Step 9: - Open/Expand App_Start folder => Open WebApiConfig.cs file => Change following line 

config.Routes.MapHttpRoute(

    name: "DefaultApi",

    routeTemplate: "api/{controller}/{id}",

    defaults: new { id = RouteParameter.Optional }

);

To

config.Routes.MapHttpRoute(

    name: "DefaultApi",

    routeTemplate: "api/{controller}/{action}/{id}",

    defaults: new { id = RouteParameter.Optional }

);

All Done

Run Project

Step 10: - Enter swagger at the end of URL and Click on Enter

http://localhost: 2319/swagger