In general, this is not a Windows Universal App problem, but simply an HTML/javascript one. By default, browsers scroll the body content that exceeds the browser window, but in the UWP JS app, no scrolling is provided by default. So, to make the content scrollable, you do need to provide a height, but the height may be dynamic. Using javascript, you can set the height more appropriately based on the user's screen size.
Basically, in the main javascript file, you can set the height of the scrollable region.
body {
overflow-y: scroll;
}
function setElementToRemainingWindowHeight(selector, usedHeight) {
$(selector).height($(window).innerHeight() - usedHeight);
}
function calculateUsedHeight() {
return $('.header').innerHeight() + $('footer').innerHeight();
}
$(function(){
setElementToRemainingWindowHeight('#scrollingRegion', calculateUsedHeight());
window.resize(function() {
setElementToRemainingWindowHeight('#scrollingRegion', calculateUsedHeight());
});
});
You can move the code to respond to whatever event in your app that would cause the scrollable area to change (maybe things are entering and exiting the surrounding layout, or whatever).
Depending on when the items in the list are added, and how that adding occurs, your requirements may change. See this post (which I wrote) about how to do this more dynamically...