how to dynamically set the active class in bootstrap navbar?

You can use this javascript to add active class based on current url please try it

<script type="text/javascript">
    $(document).ready(function () {
        var url = window.location;
        $('ul.nav a[href="'+ url +'"]').parent().addClass('active');
        $('ul.nav a').filter(function() {
             return this.href == url;
        }).parent().addClass('active');
    });
</script>