How to Use a Custom Method from a Different Namespace in Razor Views

To use helper methods or extension methods from a custom library in your Razor views, you need to add their namespace to the Views/web.config file.

For example, to use LINQ extension methods in your views, add the following line inside the <namespaces> section of the web.config file located under the Views directory:

<add namespace="System.Linq" />

When you open the Views/web.config file, you will see a list of pre-configured namespaces under <system.web.webPages.razor> / <pages> / <namespaces>. Once you add your custom namespace here, you will be able to access its methods across any of your view pages without needing to declare @using MyCustomNamespace at the top of every file.

Note: If IntelliSense does not update immediately in Visual Studio, simply close and restart the IDE to refresh the Razor compiler’s cache.