[Bug] Modal rerender for every keyup/keydown event

[BeyondDefinition]

Describe the bug
When using [CascadingParameter] ModalInstance, apparently the onkeyup and onkeydown handlers in FocusTrap sets the CascadedValue every time any keyup/keydown DOM event is generated in a child component, which rerenders the component twice for every key press.

This causes OnParametersSet to be called in Typeahead. If you remove these 2 event handlers, the Typeahead component also works as intended. See Blazored/Typeahead#288

It does seem to generate some overhead. Perhaps it's possible to disable event propagation?

To Reproduce
Steps to reproduce the behavior:

1. Create new VS project.
2. Follow the guide to add Modal
3. Make sure to add [CascadingParameter] ModalInstance and manually implement the getter + setter.
4. Trace the calls to the setter, for example with a breakpoint or Debugger.Log.

Expected behavior
Rerender only when the component state has actually changed, not twice for every key press.

Hosting Model (is this issue happening with a certain hosting model?):

• Blazor Server

[chrissainty]

Thanks for opening this issue @BeyondDefinition. I think the solution to this is pretty simple, currently the BlazoredModalInstance value that is cascaded down isn't fixed. I've just done a quick test and setting it to fixed will resolve this.

<CascadingValue Value="this" IsFixed="true">
    @Content
</CascadingValue>

[BeyondDefinition]

That indeed solves it! Thanks!
I wish it was always as easy as adding IsFixed="true" to fix an issue!
Can you please include this improvement in the next release?