How do you manually trigger the form validation in Blazor?
You have to define and bind the EditContext with EditForm and then call the method editContext.Validate() on button click to manually trigger the validation.
Is there an inline class for form attributes validation in Blazor? How do you define the validations in Razor component files?
You can define the form attribute validation in a Razor component inside the function to achieve this. Please do not forget to include the DataAnnotations in the Razor component file. Please refer to this documentation for more form validations.
Where should I access the DOM elements?
You have to access the DOM elements in OnAfterRender or OnAfterRenderAsync of the Blazor component lifecycle. [JS Helper] [Razor] Have a look at the Blazor component lifecycle for more information.
How do you instantiate a custom component in Blazor?
Instantiating a custom component at compile time is in the development phase in Blazor. You can track the thread Allow custom component instantiation for more information.
How do you handle 404 pages in Blazor?
The NotFound template section in the App.razor can be used to handling 404 pages. The router shows this content if it hits a route that is not available, which is a 404 page. Create a component Page/Error.razor to display the 404 contents. For more information, read about Blazor routing.