这是一个使用jQuery 的 fadeToggle
示例(更复杂的快捷方式animate
)
// assuming jQuery
$(function () { // on document ready
var div = $('#showOrHideDiv'); // cache <div>
$('#action').click(function () { // on click on the `<a>`
div.fadeToggle(1000); // toggle div visibility over 1 second
});
});
HTML
<a id="action" href="#">hide/show text</a>
<div id="showOrHideDiv" style="display: none;">hidden text</div>
演示
纯JavaScript推子的示例。它看起来很复杂,因为我编写它是为了支持在淡入淡出中改变方向和持续时间。不过,我确信仍然可以对其进行改进。
function generateFader(elem) {
var t = null, goal, current = 0, inProgress = 0;
if (!elem || elem.nodeType !== 1) throw new TypeError('Expecting input of Element');
function visible(e) {
var s = window.getComputedStyle(e);
return +!(s.display === 'none' || s.opacity === '0');
}
function fader(duration) {
var step, aStep, fn, thisID = ++current, vis = visible(elem);
window.clearTimeout(t);
if (inProgress) goal = 1 - goal; // reverse direction if there is one running
else goal = 1 - vis; // else decide direction
if (goal) { // make sure visibility settings correct if hidden
if (!vis) elem.style.opacity = '0';
elem.style.display = 'block';
}
step = goal - +window.getComputedStyle(elem).opacity;
step = 20 * step / duration; // calculate how much to change by every 20ms
if (step >= 0) { // prevent rounding issues
if (step < 0.0001) step = 0.0001;
} else if (step > -0.0001) step = -0.0001;
aStep = Math.abs(step); // cache
fn = function () {
// console.log(step, goal, thisID, current); // debug here
var o = +window.getComputedStyle(elem).opacity;
if (thisID !== current) return;
if (Math.abs(goal - o) < aStep) { // finished
elem.style.opacity = goal;
if (!goal) elem.style.display = 'none';
inProgress = 0;
return;
}
elem.style.opacity = (o + step).toFixed(5);
t = window.setTimeout(fn, 20);
}
inProgress = 1; // mark started
fn(); // start
}
return fader;
}
并使用它
window.addEventListener( // this section matches the code above
'load',
function () {
var fader = generateFader(document.getElementById('showOrHideDiv'));
document.getElementById('action').addEventListener(
'click',
function () {
fader(1000);
}
);
}
);
这个DEMO