In article, I have shared a way to create a Layout Razor and ViewStart in ASP.NET MVC 5.

Views/Shared

You need to create a shared folder, "Shared" in the Views directory.
Go Views/Shared directory and create new _LayoutPage1.cshtml file and write the following below code.
  1. <!DOCTYPE html>
  3. <html>
  4. <head>
  5. <meta name="viewport" content="width=device-width" />
  6. <title>@ViewBag.Title</title>
  7. </head>
  8. <body>
  9. <div>
  10. @RenderBody()
  11. </div>
  12. </body>
  13. </html>
The @RenderBody()
Use display content in multiple controllers to View.

Example you can have a fixed header and footer in the page. Only change will be the content of the RenderBody() called in the code.
  1. <html>
  2. <head>
  3. <meta name="viewport" content="width=device-width" />
  4. <title>@ViewBag.Title</title>
  5. </head>
  6. <body>
  7. <div class="header">
  8. <!--code header fixed-->
  9. </div>
  10. <div>
  11. @RenderBody()
  12. </div>
  13. <div class="footer">
  14. <!--code footer fixed-->
  15. </div>
  16. </body>
  17. </html>
So you have fixed the (header/footer) for the website.
Okay, you need using _LayoutPage1.cshtml, so you to Views/Home/index.cshtml. Open it, pass the following below code.
  1. @{
  2. ViewBag.Title = "Index";
  3. Layout = "~/Views/Shared/_LayoutPage1.cshtml";
  4. }
_ViewStart.cshtml used to define the layout for the website. You can set the layout settings as well, if HomeController is using Layout.
_LayoutHome.cshtml or AdminController is _LayoutAdmin.cshtml
  1. //Views/ViewStart.cshtml
  2. @{
  3. Layout = "~/Views/Shared/_LayoutPage1.cshtml";
  4. }
You can configuration _ViewStart.cshtml the following below code.
  1. @{
  3. string CurrentName = Convert.ToString(HttpContext.Current.Request.RequestContext.RouteData.Values["Controller"]);
  4. string clayout = "";
  5. switch (CurrentName)
  6. {
  7. case "Home":
  8. clayout = "~/Views/Shared/_LayoutHome.cshtml";
  9. break;
  10. default:
  11. //Admin layout
  12. clayout = "~/Views/Shared/_LayoutAdmin.cshtml";
  13. break;
  14. }
  15. Layout = clayout;
  17. }
This gives you an idea, how to use a Razor layout in various pages.
The previous article,