CSS Background crossfading issue

问题

i'm experiencing an issue with my background crossfading not working AT ALL. Maybe someone would be able to tell me what have i done wrong? :) Here's the script:

HTML:

<div class="bg">
    <div class="backgroundchange">
        <div class="bgimg" id="bg1">
            <div class="title centerV">
                <div>
                    <div class="text">
                        <h1>Malarstwo</h1>
                        <p>Beaty Domanskiej</p>
                    </div>
                </div>
            </div>
        </div>
        <div class="bgimg" id="bg2">
            <div class="title centerV">
                <div>
                    <div class="text">
                        <h1>Malarstwo</h1>
                        <p>Beaty Domanskiej</p>
                    </div>
                </div>
            </div>
        </div>
        <div class="bgimg" id="bg3">
            <div class="title centerV">
                <div>
                    <div class="text">
                        <h1>Malarstwo</h1>
                        <p>Beaty Domanskiej</p>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

CSS:

.bgimg {
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
    position: absolute;
    background-repeat: no-repeat;
    background-position: center center;
    transform: scale(1);
    -webkit-box-shadow: inset 4px 1px 77px 40px rgba(0,0,0,0.78);
    -moz-box-shadow: inset 4px 1px 77px 40px rgba(0,0,0,0.78);
    box-shadow: inset 4px 1px 77px 40px rgba(0,0,0,0.78);
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
}

#bg1 {
    background-image: url("../img/gallery/slonecz.jpg");
}

#bg2 {
    background-image: url("../img/gallery/motyl.jpg");
}

#bg3 {
    background-image: url("../img/gallery/slonecz.jpg");
}

@keyframes backgroundchangeFadeInOut {
    0% {
        opacity: 1;
    }

    17% {
        opacity: 1;
    }

    25% {
        opacity: 0;
    }

    92% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}

@-webkit-keyframes backgroundchangeFadeInOut {
    0% {
        opacity: 1;
    }

    17% {
        opacity: 1;
    }

    25% {
        opacity: 0;
    }

    92% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}

#backgroundchange div:nth-of-type(1) {
    animation-delay: 8s;
    -webkit-animation-delay: 8s;
}

#backgroundchange div:nth-of-type(2) {
    animation-delay: 6s;
    -webkit-animation-delay: 6s;
}

#backgroundchange div:nth-of-type(3) {
    animation-delay: 4s;
    -webkit-animation-delay: 4s;
}

#backgroundchange div {
    animation-name: backgroundchangeFadeInOut;
    animation-timing-function: ease-in-out;
    animation-iteration-count: infinite;
    animation-duration: 8s;
    -webkit-animation-name: backgroundchangeFadeInOut;
    -webkit-animation-timing-function: ease-in-out;
    -webkit-animation-iteration-count: infinite;
    -webkit-animation-duration: 8s;
}

As a result, i can see the first background set, but it never crossfades into the next one.

回答1:

Do you want smth like this?

Here is a code that works on my laptop:

CSS:

.bgimg {
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
    position: absolute;
    background-repeat: no-repeat;
    background-position: center center;
    transform: scale(1);
    -webkit-box-shadow: inset 4px 1px 77px 40px rgba(0,0,0,0.78);
    -moz-box-shadow: inset 4px 1px 77px 40px rgba(0,0,0,0.78);
    box-shadow: inset 4px 1px 77px 40px rgba(0,0,0,0.78);
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
    background-image: url("../img/gallery/slonecz.jpg");
    animation-name: backgroundchangeFadeInOut;
    animation-timing-function: ease-in-out;
    animation-iteration-count: infinite;
    animation-duration: 8s;
    -webkit-animation-name: backgroundchangeFadeInOut;
    -webkit-animation-timing-function: ease-in-out;
    -webkit-animation-iteration-count: infinite;
    -webkit-animation-duration: 8s;
}

@keyframes backgroundchangeFadeInOut {
    0% {
       background-image: url("../img/gallery/slonecz.jpg");
    }
    50% {
       background-image: url("../img/gallery/motyl.jpg");
    }
    100% {
       background-image: url("../img/gallery/slonecz.jpg");
   }
}

HTML:

<div class="bg">
    <div class="backgroundchange">
        <div class="bgimg" id="bg1">
            <div class="title centerV">
                <div>
                    <div class="text">
                        <h1>Malarstwo</h1>
                        <p>Beaty Domanskiej</p>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

回答2:

You can't set an animation without setting a css @keyframe.

add the keyframes to your all animations here is an example below:

 @-webkit-keyframes backgroundchangeFadeInOut{
            0% {transform: translateY(-100%); opacity: 0;}
            80% {transform: translateY(40%);}
            100% {transform: translateY(0%); opacity: 1;}
        }

来源：https://stackoverflow.com/questions/41522530/css-background-crossfading-issue