元素的动画不透明度

Question

如何使用CSS或jQuery来动画元素的“不透明度”？

Answer 1

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

Answer 2

CSS3过渡可以做到这一点。我做了一个鼠标激活工具栏下面：

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

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>