css - 如何在 CSS 中的图像上放置不透明的白色渐变？

Question

如果有人问这个问题，请提前道歉:我找不到它，但我不太确定我使用的关键字。

无论如何!我正在尝试在图像上放置一条不透明的白色渐变线。这是我想把它放在上面的东西:

div.horizontal
{
    position: relative;
    width: 100%;
    height:45px;
}

div.horizontal ul
{
    list-style-type:none;
    margin:0;
    padding:0;
} 

div.horizontal li
{
    float:left;
}

div.horizontal a
{
    display:block;
    width:312px;
    height:35px;
    background-image: url("../img/truefactzheader.png");
}

div.horizontal a:link,div.horizontal a:visited
{
    font-weight:bold;
    color:#FFFFFF;
    text-align:center;
    vertical-align:middle;
    padding:4px;
    text-decoration:none;
    text-transform:uppercase;
}

div.horizontal a:hover,div.horizontal a:active
{
    height:45px;
    a:link {text-decoration:none;}
    a:visited {text-decoration:none;}
}

渐变代码是这样的:

background: -moz-linear-gradient(top,  rgba(255,255,255,0) 0%, rgba(255,255,255,0.15) 51%, rgba(255,255,255,0.15) 52%, rgba(255,255,255,0) 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(255,255,255,0)), color-stop(51%,rgba(255,255,255,0.15)), color-stop(52%,rgba(255,255,255,0.15)), color-stop(100%,rgba(255,255,255,0)));
background: -webkit-linear-gradient(top,  rgba(255,255,255,0) 0%,rgba(255,255,255,0.15) 51%,rgba(255,255,255,0.15) 52%,rgba(255,255,255,0) 100%);
background: -o-linear-gradient(top,  rgba(255,255,255,0) 0%,rgba(255,255,255,0.15) 51%,rgba(255,255,255,0.15) 52%,rgba(255,255,255,0) 100%);
background: -ms-linear-gradient(top,  rgba(255,255,255,0) 0%,rgba(255,255,255,0.15) 51%,rgba(255,255,255,0.15) 52%,rgba(255,255,255,0) 100%);
background: linear-gradient(to bottom,  rgba(255,255,255,0) 0%,rgba(255,255,255,0.15) 51%,rgba(255,255,255,0.15) 52%,rgba(255,255,255,0) 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00ffffff', endColorstr='#00ffffff',GradientType=0 );

我如何让一个胜过另一个？

编辑:

我试过这个:

background: url("../img/truefactzheader.png"), -moz-linear-gradient(top,  rgba(255,255,255,0) 0%, rgba(255,255,255,0.15) 51%, rgba(255,255,255,0.15) 52%, rgba(255,255,255,0) 100%);
background: url("../img/truefactzheader.png"), -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(255,255,255,0)), color-stop(51%,rgba(255,255,255,0.15)), color-stop(52%,rgba(255,255,255,0.15)), color-stop(100%,rgba(255,255,255,0)));
background: url("../img/truefactzheader.png"), -webkit-linear-gradient(top,  rgba(255,255,255,0) 0%,rgba(255,255,255,0.15) 51%,rgba(255,255,255,0.15) 52%,rgba(255,255,255,0) 100%);
background: url("../img/truefactzheader.png"), -o-linear-gradient(top,  rgba(255,255,255,0) 0%,rgba(255,255,255,0.15) 51%,rgba(255,255,255,0.15) 52%,rgba(255,255,255,0) 100%);
background: url("../img/truefactzheader.png"), -ms-linear-gradient(top,  rgba(255,255,255,0) 0%,rgba(255,255,255,0.15) 51%,rgba(255,255,255,0.15) 52%,rgba(255,255,255,0) 100%);
background: url("../img/truefactzheader.png"), (linear-gradient(to bottom,  rgba(255,255,255,0) 0%,rgba(255,255,255,0.15) 51%,rgba(255,255,255,0.15) 52%,rgba(255,255,255,0) 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00ffffff', endColorstr='#00ffffff',GradientType=0 );

还是不行

Answer 1

渐变在 CSS 3 中被视为图像，因此只需在 background 简写属性中同时包含渐变和用逗号分隔的 bg-image，因为 CSS 3 允许使用多个背景图像。此外，因为 CSS 从右到左解析，您必须先指定渐变，然后然后图像，以使其显示在图像“上方”。