BlazorTopShelf

This sample demonstrates running a .NET 8 Blazor WebApp using VB.NET as much as possible, hosted in a Windows Service using TopShelf.

It started as the default C# project as scaffolded from the Blazor WebApp template. Identity Pages and Sample Pages were included in the scaffolding. The SignalR demo, added later, was built using this guidance.

You may call VB.NET code from a C# Razor page by adding classes to the Presentation.Operations project as needed, and then referencing them from the page's @code {} section. An example of this approach may be found in \Components\Pages\Weather.razor.

To install the service, dotnet publish to your desired output directory, and then run the following command from an elevated command prompt in that directory:

Presentation.exe install

This will install the service. You can then start it using net start BlazorTopShelf or services.msc. With the service running, navigate to http://localhost:5000/ to view the application and navigate its pages.

The installation is configured in the Host.Run() method to set the service's startup type to Automatic (Delayed Start). You can change this setting to your liking by calling HostConfig.Disabled(), HostConfig.StartManually(), HostConfig.StartAutomatically() or HostConfig.StartAutomaticallyDelayed().

To uninstall the service, run the following command from an elevated command prompt:

Presentation.exe uninstall

Here's a high-level view of how it works:

1. The C# Program class is the entry point for the application. After obtaining the OnStart() and OnStop() actions from Presentation.Operations, it initializes a Host instance, and then calls the Host.Run() method.
2. Host.Run() sets the stage for the service, including specifying what happens when the service starts and stops.
3. The Manager.StartService() method configures and invokes the constructor-provided OnStart() action—which in turn configures and starts the website—when the service starts. Note that the WebApplication class provides a Run() method, which blocks and listens on a port and which we normally use, but since TopShelf handles the blocking all we need here is the listening component, StartAsync().

Notes

• A SQLite database will be created on first run, in the directory %LocalAppData%\BlazorTopShelf.
• The TopShelf repository is located at https://github.com/Topshelf/Topshelf.