_ViewStart.cshtml is a conventionally named Razor file that runs common Razor code before pages in its directory and descendant directories execute. Its usual job is assigning a default layout, so individual pages do not repeat the same Layout setting. section 17.4.4 section 17.5
@{
Layout = "_Layout";
}
Place this code in Pages/_ViewStart.cshtml to apply _Layout as the default layout for Razor Pages beneath Pages. section 17.4.4
Use _ViewStart.cshtml to centralize presentation behavior while keeping local exceptions possible:
- Put it in the Pages folder to affect all Razor Pages below that folder. section 17.4.4
- Override the default layout in an individual Razor Page when that page needs a different layout. section 17.4.4
- Use _ViewImports.cshtml for directives such as @using; use _ViewStart.cshtml for executable Razor code. section 17.4.4
- Remember that it does not execute for layouts or partial views, and that hierarchical files execute from root folders toward more specific view folders. section 17.5
Sharing an application layout with Identity pages
Create Areas/Identity/Pages/_ViewStart.cshtml and set Layout = "/Pages/Shared/_Layout.cshtml". Identity Razor Pages then use the same base layout as the rest of the application. section 23.4.3
