[.NET HTML][Globalization] Renderer produces invalid HTML in some cultures

[mikoskinen]

Platform

• .NET HTML

Author or host

Custom Host using AdaptiveCards.Rendering.Html.

Version of SDK

AdaptiveCards.Rendering.Html version 1.2.4 from Nuget. Same issue in master branch.

Details

AdaptiveCardRenderer doesn't take into account the system's culture when a card is rendered. Because of this, the rendered cards have invalid HTML for line-height and for colors.

Example output from a computer running fi-fi -culture:

<div class='ac-adaptivecard' style='width: 100%;background-color: rgba(255, 255, 255, 1,00); padding: 15px;box-sizing: border-box;justify-content: flex-start;'>
	<div class='ac-textblock' style='box-sizing: border-box;text-align: left;color: rgba(0, 0, 0, 1,00);line-height: 18,62px;font-size: 14px;font-weight: 400;white-space: nowrap;'>
		<p style='margin-top: 0px;margin-bottom: 0px;width: 100%;text-overflow: ellipsis;overflow: hidden;'>Adaptive Cards for Blazor simple example</p>
	</div>
</div>

As you can see, the background-color's opacity and line-height both contain a comma instead of a dot.

This is because in the code the culture isn't provided so the system's culture is used:

.Style("line-height", $"{lineHeight.ToString("F")}px")

I'll submit a PR for this which makes sure that Invariant Culture is used.