常见css的兼容问题

<!-- html --><a class="noDashedBox" href="#"><img src="http://j5.dfcfw.com/image/201406/20140603152217.png" /></a>

/*
* a, img, input等标签点击时会带有虚线框
* 去除它
*/
.noDashedBox {
outline:0;
blr:expression(this.onFocus=this.blur());
}

<!-- html -->
<a class="fixedTop" href="#"><img src="http://j5.dfcfw.com/image/201406/20140603152217.png" /></a>

<a class="fixedBottom" href="#"><img src="http://j5.dfcfw.com/image/201406/20140603152217.png" /></a>

/*  css  */
.fixedTop {
position:fixed;
top:100px;
left:50%;
margin-left:500px;
_position:absolute;
_top:expression(eval(document.documentElement.scrollTop + 100));
}

.fixedBottom {
position:fixed;
bottom:50px;
left:50%;
margin-left:500px;
_position:absolute;
_top:expression(eval(document.documentElement.scrollTop + document.documentElement.clientHeight - 70));
}

<!-- html -->
<div class="pngOpacity"></div>

/*
* http://www.zhangxinxu.com/wordpress/2009/08/ +
* ie6%E4%B8%8Bpng%E8%83%8C%E6%99%AF%E4%B8%8D%E9%80%8F%E6%98%8E%E9%97%AE%E9%A2%98%E7%9A%84%E7%BB%BC%E5%90%88%E6%8B%93%E5%B1%95/
*
* ie6 png8 background 不能定位
*/
.pngOpacity {
height:228px;
background:url(http://www.zhangxinxu.com/study/image/png_test.png) no-repeat;
_background:none;
_filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled='true', sizingMethod='crop', src='http://www.zhangxinxu.com/study/image/png_test.png');
}

// png透明的js解决方案  http://www.zhangxinxu.com/study/js/png.js if (!window.XMLHttpRequest) {
window.attachEvent("onload", enableAlphaImages);
}

function enableAlphaImages(){
for (var i=0; i<document.all.length; i++){
var obj = document.all[i];
var bg = obj.currentStyle.backgroundImage;
var img = document.images[i];
if (bg && bg.match(/\.png/i) != null) {
var img = bg.substring(5,bg.length-2);
var offset = obj.style["background-position"];
obj.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+img+"', sizingMethod='crop')";
obj.style.background = "none";
} else if (img && img.src.match(/\.png$/i) != null) {
var src = img.src;
img.style.width = img.width + "px";
img.style.height = img.height + "px";
img.style.filter ="progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+src+"', sizingMethod='crop')"
img.src = "http://s1.95171.cn/b/img/pixel.gif"; //替换透明PNG的图片
} } }

<!-- html -->
<div class="opacity"><span style="color:yellow;">this is opacity text</span></div>

<div class="opacity"><span style="color:yellow;position:relative;">this is text that not opacity in ie</span></div>

.opacity {
background: #000;
filter:alpha(opacity=50);
*zoom:1;   /* sometimes it is needed */
opacity: 0.5;

font-size: 38px;
color:#fff;
}

<!-- html -->
<div class="rgbaAlpha">red green blue and alpha</div>

/* css */
.rgbaAlpha {
width:300px;
height:auto;
padding:50px;
filter:progid:DXImageTransform.Microsoft.gradient(startcolorstr=#7F000000,endcolorstr=#7F000000);
background: rgba(0, 0, 0, 0.5);

font-size: 38px;
color:#fff;
}