为什么不推荐使用 < marquee > ，最好的替代方案是什么？

I don't think you should move the content but that doesn't answer your question... Take a look at the CSS:

.marquee {
width: 450px;
line-height: 50px;
background-color: red;
color: white;
white-space: nowrap;
overflow: hidden;
box-sizing: border-box;
}
.marquee p {
display: inline-block;
padding-left: 100%;
animation: marquee 15s linear infinite;
}
@keyframes marquee {
0%   { transform: translate(0, 0); }
100% { transform: translate(-100%, 0); }
}

Here is the codepen.

Edit:

Here is the bottom to top codepen.

You just have to define class and attached looping animation once in CSS and use it afterwards everywhere you need. But, as many people said - it's a bit annoying practice, and there is a good reason, why this tag is becoming obsolete.

.example1 {
height: 50px;
overflow: hidden;
position: relative;
}
.example1 h3 {
position: absolute;
width: 100%;
height: 100%;
margin: 0;
line-height: 50px;
text-align: center;


/* Starting position */
-moz-transform:translateX(100%);
-webkit-transform:translateX(100%);
transform:translateX(100%);


/* Apply animation to this element */
-moz-animation: example1 15s linear infinite;
-webkit-animation: example1 15s linear infinite;
animation: example1 15s linear infinite;
}


/* Move it (define the animation) */
@-moz-keyframes example1 {
0%   { -moz-transform: translateX(100%); }
100% { -moz-transform: translateX(-100%); }
}
@-webkit-keyframes example1 {
0%   { -webkit-transform: translateX(100%); }
100% { -webkit-transform: translateX(-100%); }
}
@keyframes example1 {
0%   {
-moz-transform: translateX(100%); /* Firefox bug fix */
-webkit-transform: translateX(100%); /* Firefox bug fix */
transform: translateX(100%);
}
100% {
-moz-transform: translateX(-100%); /* Firefox bug fix */
-webkit-transform: translateX(-100%); /* Firefox bug fix */
transform: translateX(-100%);
}
}

<div class="example1">
<h3>Scrolling text... </h3>
</div>

As stated before: the easiest substitution is CSS animation

To all the critics of the marquee:

It is a very useful tool for UI, I am using it just on hover, to display more information in a limited space.

The example for the mp3-player is excellent, even my car-radio is using the effect to show the current song.

So nothing wrong about that, my opinion ...

<marquee> was never part of any HTML specification and what you link to is a CSS spec so it's hard to deprecate something that was never included. HTML is about structure of a document, not its presentation. So having a self-animated element as part of HTML does not abide by those goals. Animation is in CSS.

I know this was answered a couple years ago, but I found this when inspecting this. When I inspected, I found this.

@keyframes scroll {
from {
transform: translate(0,0)
}


to {
transform: translate(-300px,0)
}
}


.resultMarquee {
animation: scroll 7s linear 0s infinite;
position: absolute
}

I have created a jQuery script that will replace the old marquee tag with standard div. The code will also parse the marquee attributes like direction, scrolldelay and scrollamount. Actually the code can skip the jQuery part but I felt too lazy to do so, and the vanilla JS part is actually a solution that I modified from @Stano answere from here

Here is the code:

jQuery(function ($) {


if ($('marquee').length == 0) {
return;
}


$('marquee').each(function () {


let direction = $(this).attr('direction');
let scrollamount = $(this).attr('scrollamount');
let scrolldelay = $(this).attr('scrolldelay');


let newMarquee = $('<div class="new-marquee"></div>');
$(newMarquee).html($(this).html());
$(newMarquee).attr('direction',direction);
$(newMarquee).attr('scrollamount',scrollamount);
$(newMarquee).attr('scrolldelay',scrolldelay);
$(newMarquee).css('white-space', 'nowrap');


let wrapper = $('<div style="overflow:hidden"></div>').append(newMarquee);
$(this).replaceWith(wrapper);


});


function start_marquee() {


let marqueeElements = document.getElementsByClassName('new-marquee');
let marqueLen = marqueeElements.length
for (let k = 0; k < marqueLen; k++) {




let space = '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;';
let marqueeEl = marqueeElements[k];


let direction = marqueeEl.getAttribute('direction');
let scrolldelay = marqueeEl.getAttribute('scrolldelay') * 100;
let scrollamount = marqueeEl.getAttribute('scrollamount');


let marqueeText = marqueeEl.innerHTML;


marqueeEl.innerHTML = marqueeText + space;
marqueeEl.style.position = 'absolute';


let width = (marqueeEl.clientWidth + 1);
let i = (direction == 'rigth') ? width : 0;
let step = (scrollamount !== undefined) ? parseInt(scrollamount) : 3;


marqueeEl.style.position = '';
marqueeEl.innerHTML = marqueeText + space + marqueeText + space;






let x = setInterval( function () {


if ( direction.toLowerCase() == 'left') {


i = i < width ? i + step : 1;
marqueeEl.style.marginLeft = -i + 'px';


} else {


i = i > -width ? i - step : width;
marqueeEl.style.marginLeft = -i + 'px';


}


}, scrolldelay);


}
}


start_marquee ();
});

And here is a working codepen