css - 为什么我的气球不能正常飞行？ CSS动画翻译

Question

我正在尝试使用 CSS 翻译执行以下操作:

单击按钮时，气球会出现并飞走。当它们完成飞行时，它们会消失并返回到起始位置(以便下次单击按钮时会发生相同的行为)。

到目前为止我得到了following (气球只是向上飞，不会出现/消失)。

HTML

<div>
    <img class="object" src="http://pngimg.com/upload/balloon_PNG580.png" />
</div>
<br><br><button id="button">Fly!!!</button>

CSS

div{
    height: 300px;
    position: relative;
}
.object {
    width: 60px;
    position: absolute;
    bottom: 0;
    -webkit-transition: all 1s ease-in-out;
    -moz-transition:    all 1s ease-in-out;
    -o-transition:      all 1s ease-in-out;
}
.move-up{
    transform:         translate(0,-150px);
    -webkit-transform: translate(0,-150px);
    -o-transform:      translate(0,-150px); 
    -moz-transform:    translate(0,-150px);
}

JS

$('#button').click(function(){
    $('.object').addClass('move-up');
});

问题是，当我尝试将起始 display : none 添加到对象并单击添加 $('.object').show() 时，它会出现我的动画根本没有开始。如何让我的气球飞起来？

Answer 1

您可以使用 CSS3 动画来实现此效果。请参阅内嵌评论以了解每个元素的更多详细信息。

CSS:

.object {
    width: 60px;
    position: absolute;
    bottom: 0;
    opacity: 0; /* make the balloon invisible on load and once animation is complete */
}

.move-up{
    -webkit-animation: balloon 1s linear; /* the animation to move up */
    -moz-animation: balloon 1s linear;
    animation: balloon 1s linear;
}

@keyframes balloon { /* included only unprefixed version to keep answer short, demo has the prefixed versions also */
    5% {
        transform: translate(0, 0); /* keep at original position */
        opacity: 1; /* make opacity as 1 after a short time for balloon to appear */
    }
    50% {
        transform: translate(0, -150px); /* move up */
        opacity: 1; /* retain the opacity */
    }
    55%, 100% {
        transform: translate(0, -150px); /* retain translated position till end */
        opacity: 0; /* hide the ballons and make it hidden for the rest of the duration */
    }
}

jQuery:

$('#button').click(function(){
    $('.object').addClass('move-up'); // adding the move up animation class to make it move
    $('.object.move-up').on('animationend webkitAnimationEnd MSAnimationEnd oAnimationEnd',function(){
        $('.object').removeClass('move-up'); // removing the animation class on animation end to make it come back to original state
    });
});

Demo