Function on window.scroll and get the vertical offset [duplicate]

问题

window.scroll=function MyFunc(){
	var y = window.scrollTop();
	alert(y);
}

How to call a function when the window is scrolled and how to get the amount of pixels the window has been vertically scrolled. I want to play an animation when a desired value has been reached. Help.

回答1:

You can use window.onscroll without the use of jQuery. That was what you were missing on your code. It should be window.onscroll and to get the vertical scroll pixels use window.scrollY

window.onscroll = function (e) {
  console.log(window.scrollY);
};

html, body{
  height: 2000px;
}

回答2:

You need to wrap the window object in $() to use the scrollTop() function on it.

$(window).scroll(function MyFunc(e){
	var y = $(window).scrollTop();
	console.log(y);
});

html, body{
  height: 2000px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

In Javascript, you can add an event listener for the scroll event on the window and use window.pageYOffset (for better cross-browser compatability) to get the amount of pixels scrolled vertically.

window.addEventListener("scroll", function MyFunc(e){
  var y = (window.pageYOffset !== undefined)
  ? window.pageYOffset
  : (document.documentElement || document.body.parentNode || document.body).scrollTop;//for cross-browser compatability
  console.log(y);
});

html, body{
  height: 2000px;
}

来源：https://stackoverflow.com/questions/51933055/function-on-window-scroll-and-get-the-vertical-offset

标签

javascript

jquery

html