How can I tell when Blazor has finished rendering a DOM element?

The lifecycle methods OnAfterRenderAsync and OnAfterRender are called only when a component has finished rendering. The element and component references are populated at this point. By using these methods, the user can activate third-party JavaScript libraries that operate based on the DOM elements.  Razor file 

How is Blazor UI notified when the property value is changed?

Blazor notifies the UI changes automatically whenever the bound property is changed in a button click, input text, dropdown, etc.Blazor triggers the StateHasChanged() method to notify the change. However, there are some exceptional cases where the user has to manually call the StateHasChanged() method to notify that the UI has been updated.  By calling the StateHasChanged(), Blazor can manually be notified when to rerender its UI. This method will tell Blazor when to refresh the UI. In the above example, when the button is clicked, the UI will refresh for every count down of the timer since StateHasChanged method has been called to refresh the UI.