javascript – 检测故意的顶部和底部额外滚动

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我试图用 javascript检测一个有意的额外顶部/底部滚动. $(window).scrollTop()和window.pageYOffset没用,因为它们停在Top 0,我想达到类似top -X的东西.对于底部,假设我的文档高度为500,底部就像底部5XX.

编辑:
示例代码可以是:

$(window).scroll(function(){

  if(intentionalScrollTop){
    // Do something
  }else if(intentionalScrollDown){
    // Do something
  }

});

Gif例子:

解决方法

我从你的问题中理解的不仅是“检测到过度滚动”……
但也可以用它来创建你在问题中显示的动画.

我使用包装div做了一个解决方案,就像我2天前评论的那样.

您可以在CodePen或下面的代码段中看到它.

$(document).ready(function(){
	    
    var at_Top=true;
    var at_Bottom=false;
	var prevIoUs_scrolled;
	var triggerTime=0;
    var scroll_dir=false;   // false=>Down true=>up
	var scrolled_bottom = $("body").height() - $(window).height();
	var animationDelay = 300;
	var animationTimeout = 350;		//Max delay between 2 triggers is 1 sec.
									//So keep this value under 400ms
									//Because one complete animation is 300ms+350ms+300ms.
									//To have longer animation delays,add time to the triggerDelay
	
	var triggerDelay=0;	// You can add more delay to allow the next trigger (in seconds).
	
    $(window).scroll(function(){
        var scrolled=$(window).scrollTop();

        // Reached the top?
        if(scrolled==0){
            at_Top=true;
        }else{
            at_Top=false;
        }

        // Reached the bottom?
        if(scrolled==scrolled_bottom){
            at_Bottom=true;
        }else{
            at_Bottom=false;
        }
        
        // Scroll direction
		if( $(this).scrollTop() > prevIoUs_scrolled ){
			scroll_dir=false;  //scroll down
		}else{
			scroll_dir=true;  //scroll up
		}
		
		// Keep prevIoUs scrollTop position in memory
		prevIoUs_scrolled = $(this).scrollTop();
		
		animationTrigger();
    });

	function animationTrigger(){
        if(at_Top && scroll_dir){
            console.log("Scrolling when at top.");
			$("#wrapper").stop().animate({"margin-top":"3em"},animationDelay);
			setTimeout(function(){
				$("#wrapper").stop().animate({"margin-top":0},animationDelay);
			},animationTimeout);
			clearTimeout(clearConsole);
			var clearConsole = setTimeout(function(){
				console.clear();
			},3000);
        }
        if(at_Bottom && !scroll_dir){
            console.log("Scrolling when at bottom.")
			$("#header").stop().animate({"height":0},animationDelay);
			$("#footer-spacer").stop().animate({"height":"3em"},animationDelay);
			setTimeout(function(){
				$("#header").stop().animate({"height":"3em"},animationDelay);
				$("#footer-spacer").stop().animate({"height":0},3000);
        }
    }
	
    // KEYBOARD ARROWS UP/DOWN AND PAGE UP/DOWN SCROLLING
    $(window).on("keydown",function(e){
        //console.log(e.which);
        if( (e.which==38) || (e.which==33) ){    // Arrow up or Page up
            scroll_dir=true;
        }
        if( (e.which==40) || (e.which==34) ){    // Arrow down or Page down
            scroll_dir=false;
        }
		
		// Limit triggers to 1 per second... Because when holding a key down for long,it triggers too fast...
		var thisSecond = new Date().getSeconds()
        if( (triggerTime != thisSecond) || (triggerTime < (thisSecond - triggerDelay) ) ){
            animationTrigger();
            triggerTime=thisSecond;
        }
    })

    // WHEEL SCROLLING
    // Inspired from this SO answer: https://stackoverflow.com/a/7309786/2159528

    //Firefox
    $(window).bind('DOMMouseScroll',function(e){
        var scrolled2=$(window).scrollTop();
        
        if(e.originalEvent.detail > 0) {
            scroll_dir=false;  //scroll down
            //console.log("down");
        }else {
            scroll_dir=true;   //scroll up
            //console.log("up");
        }
        
		// Limit triggers to 1 per second... Because wheel turns quite fast.
        var thisSecond = new Date().getSeconds()
        if( (triggerTime != thisSecond) || (triggerTime < (thisSecond - triggerDelay) ) ){
            animationTrigger();
            triggerTime=thisSecond;
        }
    });

    //IE,Opera,Safari
    $(window).bind('mousewheel',function(e){
		
        if(e.originalEvent.wheelDelta < 0) {
            scroll_dir=false;  //scroll down
        }else {
            scroll_dir=true;   //scroll up
        }
        
        // Limit triggers to 1 per second... Because wheel turns quite fast.
        var thisSecond = new Date().getSeconds()
        if( (triggerTime != thisSecond) || (triggerTime < (thisSecond - triggerDelay) ) ){
            animationTrigger();
            triggerTime=thisSecond;
        }
    });

});	// End Document.ready
body,wrapper{
    padding:0;
    margin:0;
    height:100;
}
#page{
    height:1500px;
    width:100%;
}
#header,#footer{
    height:3em;
    padding:0.5em;
    background-color:cyan;
}
#content{
    height:calc(100% - 8em);    /* -8em for header and footer... (height: 3em + padding: 2x 0,5em) */
    padding:0 0.5em;
    overflow:hidden;
}
#footer-spacer{
    height:0px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="wrapper">
    <div id="page">
        <div id="header">
            This is the page's top
        </div>
        <div id="content">
            <h1>Scroll this page to see the overscroll effect at top and bottom</h1>
            <br>
            <ul>
                <li>using the mouse wheel</li>
                <li>keyboard arrows</li>
                <li>keyboard page up/down</li>
            </ul>
            <br>
            <br>
            Content...<br>
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        </div>
        
        <div id="footer">
            This is the page's bottom
        </div>
        <div id="footer-spacer"></div>
    </div>
</div>

页面位于顶部或底部时检测滚动尝试…
用它来设置你展示的动画是另一个.

顶部的方法
包装器的边距从0em到3em动画,将标题内容向下推.
因此页面“看起来”像过度滚动.

底部方法
这是一个挑战……
不能与包装器的margin-bottom顶部相同,因为它可以工作……但是在视口下面,这不是我们想要的.

所以在这种情况下,我将“内容”定义为height:calc(100% – 8em)(页眉和页脚都有高度:3em和填充:0.5em)只是为了确保包装器100%填充.动画的空div在页脚下…当它的高度从0em到3em时,它通过向上推动页脚来创建过度滚动“幻觉”.

请注意,标题会在同一时间缩回,以释放空间.此时,标题不可见,为什么不呢?

拖动滚动条,旋转鼠标滚轮并按下键盘上4个“常用”键中的1个(箭头和向上/向下翻页)时,此脚本可以正常工作.

我留下了很多console.log(),您可以使用它来探索它是如何工作的,并改进动画并使其成为您的品味. 原文链接:https://www.f2er.com/js/157077.html

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