js scrollTop到达指定位置!

很早之前就想分享这篇心得, 幸之今天能在这里完成, 好了, 话不多说, 进入正题 :

方法主要利用scrolltop值做运动, 用于到达用户指定的位置(如返回顶部把参数target设置为0即可),处理了多种情况如 scrolltop > 目标值 向上运动 ,等4种情况 , 代码及用法贴上,

goTo = function(target){
    var scrollT = document.body.scrollTop|| document.documentElement.scrollTop
    if (scrollT >target) {
        var timer = setInterval(function(){
            var scrollT = document.body.scrollTop|| document.documentElement.scrollTop
            var step = Math.floor(-scrollT/6);
            document.documentElement.scrollTop = document.body.scrollTop = step + scrollT;
            if(scrollT <= target){
                document.body.scrollTop = document.documentElement.scrollTop = target;
                clearTimeout(timer);
            }
        },20)
    }else if(scrollT == 0){
        var timer = setInterval(function(){
            var scrollT = document.body.scrollTop|| document.documentElement.scrollTop
            var step = Math.floor(300/3*0.7);
            document.documentElement.scrollTop = document.body.scrollTop = step + scrollT;
            console.log(scrollT)
            if(scrollT >= target){
                document.body.scrollTop = document.documentElement.scrollTop = target;
                clearTimeout(timer);
            }
        },20)
    }else if(scrollT < target){
        var timer = setInterval(function(){
            var scrollT = document.body.scrollTop|| document.documentElement.scrollTop
            var step = Math.floor(scrollT/6);
            document.documentElement.scrollTop = document.body.scrollTop = step + scrollT;
            if(scrollT >= target){
                document.body.scrollTop = document.documentElement.scrollTop = target;
                clearTimeout(timer);
            }
        },20)
    }else if(target == scrollT){
        return false;
    }
}

用法 function(target) / / 目前唯一target(目标距离number) ,

on(goPs,'click',function(){ goTo(2450) }); //运动到scrolltop值为2450地位置,下面也一样, 运动到指定的位置 
on(goJob,'click',function(){ goTo(3373) })on(goTel,'click',function(){ buffer.goTo(3373) });
on(goMe,'click',function(){ buffer.goTo(1539) })on(goHome,'click',function(){ buffer.goTo(0) });
on(scrollgoOne,'click',function(){ buffer.goTo(2450) });on(scrollgoPc,'click',function(){ buffer.goTo(2450) });
on(scrollJob,'click',function(){ buffer.goTo(3373) });on(scrollMe,'click',function(){ buffer.goTo(1539) });
on(goTop,'click',function(){ buffer.goTo(0) })

转载自:https://www.cnblogs.com/bbyz/p/3968583.html

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转载自blog.csdn.net/rencaishigepi/article/details/85273568