无法控制div内图像的不透明度

Question

我想div中的图像是不透明的,而div是透明的.我尝试设置图像和div的不透明度,但它不起作用.

jsFiddle链接:http://jsfiddle.net/2BNEF/10/

我希望图像不透明,文本透明可见.

<div id="targetframe">
    It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various versions have evolved over the years, sometimes
    <div id="target">
        out. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their defaul
        <img class="myimage" src="http://www4.picturepush.com/photo/a/1365552/480/trucks-photgraphy/asdf-%2858%29.jpg?v0"/>
    </div>
</div>


#targetframe {
    background: none repeat scroll 0 0 black;
    border: 2px inset grey;
    font-family: Verdana,sans-serif;
    left: 0;
    margin: 0;
    overflow: hidden;
    padding: 0;
    position: absolute;
    top: 0;
    opacity: 0.5;
}
#target {
    background: none repeat scroll 0 0 transparent;
    height: 100%;
    left: 0;
    position: relative;
    top: 0;
    width: 100%;
    z-index: 0;
}
.myimage {
    opacity: 1;
}

Answer 1

如果您opacity在元素上进行设置，则该元素将被该元素的所有后代（子代，所有子代的子代...）继承，您无能为力。

在这种情况下，你可以只使用一个RGBA背景（rgba(0,0,0,.5)而不是黑色- DEMO）的股利。RGBa具有出色的支持-唯一不支持RGBa的浏览器是IE8和更低版本，对于那些您可以使用filter渐变的浏览器。