JQuery Scroll detection fire once

问题

I have a small piece of JQuery designed to collapse my header, change its dimensions, and then stick it to the side of the screen. It all works apart from one part, the height 'toggle' function fires every time the user scrolls, which gets really irritating.

Is there a way I can detect scroll only once OR toggle only once?

$(window).scroll(function () {
var width = $(document).width() - 205;
var height = $(document).height();
  $('#me').animate({
    marginLeft: width,
    width: '22px',
    height: 'toggle',
    borderLeftWidth: "10px",
    borderRightWidth: "10px"    
  }, 1000, function() {
    $("#me:first").css("margin-top","-90px");
    var div = $('#me');
    $('#me h1').css("font-size","30px");
    var start = $(div).offset().top;
    $(div).css("height", height);
    $.event.add(window, "scroll", function() {
        var p = $(window).scrollTop();
        $(div).css('position',((p)>start) ? 'fixed' : 'static');
        $(div).css('top',((p)>start) ? '0px' : '');
    });
  });
});

回答1:

look at jquery's one() functionality http://api.jquery.com/one/

It will only fire once and then promptly remove itself..

回答2:

use a flag to check it is first time or not

var doHeightToggle=true;


$.event.add(window, "scroll", function() {
   if(doHeightToggle)
   {
        var p = $(window).scrollTop();
        $(div).css('position',((p)>start) ? 'fixed' : 'static');
        $(div).css('top',((p)>start) ? '0px' : '');
        doHeightToggle = false;
   } 
});

来源：https://stackoverflow.com/questions/12731795/jquery-scroll-detection-fire-once