javascript - 用动画滚动

Question

我需要用动画执行 javascript 方法 scrollTo(x, y)。我不能'使用 jQuery 来做到这一点。

Answer 1

[工作演示]

function interpolate( source,target,pos ) { 
  return ( source + (target - source) * pos ); 
}

function easing( pos ) { 
    return ( -Math.cos( pos * Math.PI ) / 2 ) + 0.5; 
}

function scrollTop( duration ) {

  duration = duration || 1000;

  var startY = window.pageYOffset,
      start  = Number(new Date()),
      finish = start + duration;

  var interval = setInterval(function() {

    var now = Number(new Date()),
        pos = (now > finish) ? 1 : (now - start) / duration;

     scrollTo(0, interpolate( startY, 0, easing(pos) ));

     if ( now > finish )
       clearInterval( interval );
  }, 15);
};

Answer 2

您可以使用 window.setTimeout() 和 window.clearTimeout() 调用在 Javascript 中（几乎）为任何内容设置动画。见http://www.w3schools.com/js/js_timing.asp