Sharing a Layout.cshtml Between Razor Pages and MVC in ASP.NET Core

Discover how to share a single `_Layout.cshtml` across both Razor Pages and MVC in ASP.NET Core, optimizing your code and adhering to DRY principles.
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This video is based on the question https://stackoverflow.com/q/68387099/ asked by the user 'Jeff Dege' ( https://stackoverflow.com/u/243563/ ) and on the answer https://stackoverflow.com/a/68387170/ provided by the user 'Yiyi You' ( https://stackoverflow.com/u/13593736/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Sharing a _Layout.cshtml Between Razor Pages and MVC in ASP.NET Core

When building web applications with ASP.NET Core, developers often utilize both Razor Pages and MVC. However, a common challenge arises when trying to maintain a consistent visual style by sharing layouts across these two components. This guide aims to address the question: Is it possible to share a single _Layout.cshtml file between Razor pages and MVC pages?

The Challenge of Layout Sharing

In a .NET 5.0 web application, you typically have a structure that includes both Razor Pages and MVC pages. For instance, you might have your Razor pages stored as follows:

/Pages/MyRazorPage.cshtml

/Pages/MyRazorPage.cshtml.cs

And your MVC pages like this:

/Controllers/MyMvcController.cs

/Views/MyMvc/Index.cshtml

Duplicating layout files for each framework can lead to code redundancy, which contradicts the Don't Repeat Yourself (DRY) principle. Hence, sharing one layout file would be an efficient solution.

The Solution: Using a Single Layout File

Step-by-Step Instructions

Create Your Shared Layout:
First, ensure you have your layout file ready in the Razor Pages directory. The desired layout should be located at:

/Pages/Shared/_Layout.cshtml

Configure the MVC View to Use the Razor Layout:
To allow the MVC views to reference this Razor layout, you need to make a small adjustment in your _ViewStart.cshtml file located in /Views/Shared/_ViewStart.cshtml. Change the code as follows:

[[See Video to Reveal this Text or Code Snippet]]

This configuration tells the MVC views to utilize the layout found in the Razor Pages directory instead of creating a separate layout for the MVC structure.

Important Considerations

Ensure Routing is Set Up Properly:
Make sure that you have set up your Startup.Configure method correctly to include both Razor Pages and MVC handlers. An example configuration might look like this:

[[See Video to Reveal this Text or Code Snippet]]

Handling asp-page Helpers:
If you move the layout to be shared, be aware that the asp-page helpers might not work out of the box when you use plain href= tags instead. Adjust your navigation as necessary to ensure proper routing.

Benefits of This Approach

Reduced Code Duplication: Maintaining a single layout file means changes to the layout will automatically reflect across both your Razor and MVC pages.

Simplified Maintenance: With only one layout file to manage, you'll spend less time on updates and more time developing new features.

Consistency: A shared layout ensures a uniform design and user experience across your application.

Conclusion

In summary, sharing a _Layout.cshtml between Razor Pages and MVC in ASP.NET Core is not only possible but also beneficial for maintaining clean, efficient code. By properly configuring your application, you can enjoy the advantages of unified design without falling prey to unnecessary duplication. Implementing this method will enhance both the maintainability and the visual coherence of your web application.

Explore this method today to streamline your ASP.NET Core projects!