我会推荐使用 jQuery(这是一个惊喜,对吧?!:P)
$(document).ready(function() { //when document is ready
var topDist = $("nav").position(); //save the position of your navbar !Don't create that variable inside the scroll function!
$(document).scroll(function () { //every time users scrolls the page
var scroll = $(this).scrollTop(); //get the distance of the current scroll from the top of the window
if (scroll > topDist.top - *distance_nav_from_top*) { //user goes to the trigger position
$('nav').css({position:"fixed", width: "100%", top:"*distance_nav_from_top*"}); //set the effect
} else { //window is on top position, reaches trigger position from bottom-to-top scrolling
$('nav').css({position:"static", width:"initial", top:"initial"}); //set them with the values you used before scrolling
}
});
});
我真的希望我能帮上忙!