//页面加载完后触发
window.onload = function () {
var back = document.getElementById("back");
back.onclick = function () {
var time = setInterval(function () {
var top = document.documentElement.scrollTop || document.body.scrollTop;
if (top === 0) {
clearInterval(time);
} else {
document.documentElement.scrollTop = top - 20;
}
}, 1);
}
};
//jquery写法
$(function () {
$("#back").click(function () {
var time = setInterval(function () {
var top = document.documentElement.scrollTop || document.body.scrollTop;
if (top === 0) {
clearInterval(time);
} else {
window.scrollTo(0, top - 100);
}
}, 10);
});
});