问题
Currently, I have this code:
@-webkit-keyframes blinker {
from { opacity: 1.0; }
to { opacity: 0.0; }
}
.waitingForConnection {
-webkit-animation-name: blinker;
-webkit-animation-iteration-count: infinite;
-webkit-animation-timing-function: cubic-bezier(.5, 0, 1, 1);
-webkit-animation-duration: 1.7s;
}
It blinks, but it only blinks in \"one direction\". I mean, it only fades out, and then it appears back with opacity: 1.0, then again fades out, appears again, and so on...
I would like it to fade out, and then \"raise\" from this fade back again to opacity: 1.0. Is that possible?
回答1:
You are first setting opacity: 1; and then you are ending it on 0, so it starts from 0% and ends on 100%, so instead just set opacity to 0 at 50% and the rest will take care of itself.
Demo
.blink_me {
animation: blinker 1s linear infinite;
}
@keyframes blinker {
50% {
opacity: 0;
}
}<div class="blink_me">BLINK ME</div>Here, I am setting the animation duration to be 1 second, and then I am setting the timing to linear. That means it will be constant throughout. Last, I am using infinite. That means it will go on and on.
Note: If this doesn't work for you, use browser prefixes like
-webkit,-mozand so on as required foranimationand@keyframes. You can refer to my detailed code here
As commented, this won't work on older versions of Internet Explorer, and for that you need to use jQuery or JavaScript...
(function blink() {
$('.blink_me').fadeOut(500).fadeIn(500, blink);
})();
Thanks to Alnitak for suggesting a better approach.
Demo (Blinker using jQuery)
回答2:
Use the alternate value for animation-direction (and you don't need to add any keframes this way).
alternateThe animation should reverse direction each cycle. When playing in reverse, the animation steps are performed backward. In addition, timing functions are also reversed; for example, an ease-in animation is replaced with an ease-out animation when played in reverse. The count to determinate if it is an even or an odd iteration starts at one.
CSS:
.waitingForConnection {
animation: blinker 1.7s cubic-bezier(.5, 0, 1, 1) infinite alternate;
}
@keyframes blinker { to { opacity: 0; } }
I've removed the from keyframe. If it's missing, it gets generated from the value you've set for the animated property (opacity in this case) on the element, or if you haven't set it (and you haven't in this case), from the default value (which is 1 for opacity).
And please don't use just the WebKit version. Add the unprefixed one after it as well. If you just want to write less code, use the shorthand.
回答3:
The best way to get a pure "100% on, 100% off" blink, like the old <blink> is like this:
.blink {
animation: blinker 1s step-start infinite;
}
@keyframes blinker {
50% {
opacity: 0;
}
}<div class="blink">BLINK</div>回答4:
Alternatively if you do not want a gradual transition between show and hide (e.g. a blinking text cursor) you could use something like:
/* Also use prefixes with @keyframes and animation to support current browsers */
@keyframes blinker {
from { visibility: visible }
to { visibility: hidden }
/* Alternatively you can do this:
0% { visibility: visible; }
50% { visibility: hidden; }
100% { visibility: visible; }
if you don't want to use `alternate` */
}
.cursor {
animation: blinker steps(1) 500ms infinite alternate;
}
Every 1s .cursor will go from visible to hidden.
If CSS animation is not supported (e.g. in some versions of Safari) you can fallback to this simple JS interval:
(function(){
var show = 'visible'; // state var toggled by interval
var time = 500; // milliseconds between each interval
setInterval(function() {
// Toggle our visible state on each interval
show = (show === 'hidden') ? 'visible' : 'hidden';
// Get the cursor elements
var cursors = document.getElementsByClassName('cursor');
// We could do this outside the interval callback,
// but then it wouldn't be kept in sync with the DOM
// Loop through the cursor elements and update them to the current state
for (var i = 0; i < cursors.length; i++) {
cursors[i].style.visibility = show;
}
}, time);
})()
This simple JavaScript is actually very fast and in many cases may even be a better default than the CSS. It's worth noting that it is lots of DOM calls that make JS animations slow (e.g. JQuery's $.animate()).
It also has the second advantage that if you add .cursor elements later, they will still animate at exactly the same time as other .cursors since the state is shared, this is impossible with CSS as far as I am aware.
回答5:
I don't know why but animating only the visibility property is not working on any browser.
What you can do is animate the opacity property in such a way that the browser doesn't have enough frames to fade in or out the text.
Example:
span {
opacity: 0;
animation: blinking 1s linear infinite;
}
@keyframes blinking {
from,
49.9% {
opacity: 0;
}
50%,
to {
opacity: 1;
}
}<span>I'm blinking text</span>回答6:
@-webkit-keyframes blinker {
0% { opacity: 1.0; }
50% { opacity: 0.0; }
100% { opacity: 1.0; }
}
回答7:
Change duration and opacity to suit.
.blink_text {
-webkit-animation-name: blinker;
-webkit-animation-duration: 3s;
-webkit-animation-timing-function: linear;
-webkit-animation-iteration-count: infinite;
-moz-animation-name: blinker;
-moz-animation-duration: 3s;
-moz-animation-timing-function: linear;
-moz-animation-iteration-count: infinite;
animation-name: blinker;
animation-duration: 3s;
animation-timing-function: linear;
animation-iteration-count: infinite; color: red;
}
@-moz-keyframes blinker {
0% { opacity: 1.0; }
50% { opacity: 0.3; }
100% { opacity: 1.0; }
}
@-webkit-keyframes blinker {
0% { opacity: 1.0; }
50% { opacity: 0.3; }
100% { opacity: 1.0; }
}
@keyframes blinker {
0% { opacity: 1.0; }
50% { opacity: 0.3; }
100% { opacity: 1.0; }
}
回答8:
Late but wanted to add a new one with more keyframes ... here is an example on CodePen since there was an issue with the built-in code snippets:
.block{
display:inline-block;
padding:30px 50px;
background:#000;
}
.flash-me {
color:#fff;
font-size:40px;
-webkit-animation: flash linear 1.7s infinite;
animation: flash linear 1.7s infinite;
}
@-webkit-keyframes flash {
0% { opacity: 0; }
80% { opacity: 1; color:#fff; }
83% { opacity: 0; color:#fff; }
86% { opacity: 1; color:#fff;}
89% { opacity: 0}
92% { opacity: 1; color:#fff;}
95% { opacity: 0; color:#fff;}
100% { opacity: 1; color:#fff;}
}
@keyframes flash {
0% { opacity: 0; }
80% { opacity: 1; color:#fff; }
83% { opacity: 0; color:#fff; }
86% { opacity: 1; color:#fff;}
89% { opacity: 0}
92% { opacity: 1; color:#fff;}
95% { opacity: 0; color:#fff;}
100% { opacity: 1; color:#fff;}
}<span class="block">
<span class="flash-me">Flash Me Hard</span>
</span>回答9:
<style>
.class1{
height:100px;
line-height:100px;
color:white;
font-family:Bauhaus 93;
padding:25px;
background-color:#2a9fd4;
border:outset blue;
border-radius:25px;
box-shadow:10px 10px green;
font-size:45px;
}
.class2{
height:100px;
line-height:100px;
color:white;
font-family:Bauhaus 93;
padding:25px;
background-color:green;
border:outset blue;
border-radius:25px;
box-shadow:10px 10px green;
font-size:65px;
}
</style>
<script src="jquery-3.js"></script>
<script>
$(document).ready(function () {
$('#div1').addClass('class1');
var flag = true;
function blink() {
if(flag)
{
$("#div1").addClass('class2');
flag = false;
}
else
{
if ($('#div1').hasClass('class2'))
$('#div1').removeClass('class2').addClass('class1');
flag = true;
}
}
window.setInterval(blink, 1000);
});
</script>
回答10:
It works for me by using class=blink for the respective element(s)
Simple JS Code
// Blink
setInterval(function()
{
setTimeout(function()
{
//$(".blink").css("color","rgba(0,0,0,0.1)"); // If you want simply black/white blink of text
$(".blink").css("visibility","hidden"); // This is for Visibility of the element
},900);
//$(".blink").css("color","rgba(0,0,0,1)"); // If you want simply black/white blink of text
$(".blink").css("visibility","visible"); // This is for Visibility of the element
},1000);
来源：https://stackoverflow.com/questions/16344354/how-to-make-blinking-flashing-text-with-css-3