动画元素的不透明度

Question

如何使用CSS或jQuery动画元素的“不透明度”？

Answer 1

当然，使用CSS转换：

div {
    opacity: 1;
    -moz-transition: all 0.3s ease-out;    /* FF4+ */
    -o-transition: all 0.3s ease-out;      /* Opera 10.5+ */
    -webkit-transition: all 0.3s ease-out; /* Safari 3.2+, Chrome */
    -ms-transition: all 0.3s ease-out;     /* IE10+ */
    transition: all 0.3s ease-out;         /* standard format */
}

div:hover {
    opacity: 0.3;    
}

<div>Hover over me with your mouse!</div>
<div>Hover over me with your mouse!</div>
<div>Hover over me with your mouse!</div>
<div>Hover over me with your mouse!</div>
<div>Hover over me with your mouse!</div>
<div>Hover over me with your mouse!</div>

Answer 2

CSS3过渡可以做到这一点。我正在为鼠标激活的工具栏执行以下操作：

CSS

<style type="text/css">
#cmsToolBar {
    font-family: helvetica,arial,sans-serif;
    font-size: 1.1em;
    padding: 5px;
    line-height: 1.5;
    min-height: 1em;
    width: 100%;
    position: fixed;
    top: 0;
    left: 0;
    color: black;
    background-color: #DDDDBB;
    opacity: 0.15;
    border-bottom: dotted 1px black;
    transition-duration: .2s;
    -moz-transition-duration: .2s;
    -webkit-transition-duration: .2s;
    -o-transition-duration: .2s;
}
#cmsToolBar:hover {
    min-height: 5em;
    opacity: .98;
}
</style>

HTML

<div id="cmsToolBar">
  <p>This is where the CMS tool bar will go</p>
</div>

Answer 3

没有。您需要使用.fadeIn('slow or fast')或.fadeOut('slow or fast')