How do I start building a new component for Blazor?
Blazor considers each .razor file as a new component. The component class is usually written in the form of a Razor markup page. So, you can create a new component and reuse it across the application. In the following example, a Blazor component is created in the Components folder and used in the Index.razor page. [BlazorComponent.razor] [Index.razor] View Sample in GitHub
How can I prevent uploading a large file to the server?
Blazor has a built-in InputFile component from .NET 5.0 that can be used to upload files to the server. You can check the file size in the OnChange event and upload or prevent uploading the files to the server. [Index.razor] Note: Syncfusion offers a feature-rich, easy-to-use File Upload component for Blazor. You can check it out here.
How do I capture a browser KeyPress event in a Blazor server-side app and perform certain hotkey functions?
To detect a browser keypress event, set the @onkeypress event to the corresponding element. For hotkey functions, you can use the event arguments to check whether the Ctrl, Shift, or Alt key is pressed. [Index.razor] For more information on this topic, check this documentation.
If the raw HTML includes a property reference (i.e. @counter), is there any way of sending @counter as a parameter?
Raw HTML can be rendered in Blazor by using MarkupString. You can define the property and pass it to a parameter by using MarkupString. [Index.razor]
Can I host blazor server side using signalr service without using Azure?
Yes, you can host and deploy the blazor server-side application without using Azure but by using AWS or Firebase. Here you can find the steps for hosting the Blazor application using AWS. For more details reference the links Host the application to AWS and Host the application to Firebase.