CSS 背景不透明，rgba 不能在 IE8中工作

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最佳答案

Create a png which is larger than 1x1 pixel (thanks thirtydot), and which matches the transparency of your background.

EDIT : to fall back for IE6+ support, you can specify bkgd chunk for the png, this is a color which will replace the true alpha transparency if it is not supported. You can fix it with gimp eg.

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You use css to change the opacity. To cope with IE you'd need something like:

.opaque {
opacity : 0.3;
-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=30)";
filter: alpha(opacity=30);
}

But the only problem with this is that it means anything inside the container will also be 0.3 opacity. Thus you'll have to change your HTML to have another container, not inside the transparent one, that holds your content.

Otherwise the png technique, would work. Except you'd need a fix for IE6, which in itself could cause problems.

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the transparent png image will not work in IE 6-, alternatives are:

with CSS:

.transparent {


/* works for IE 5+. */
filter:alpha(opacity=30);


/* works for IE 8. */
-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=30)";


/* works for old school versions of the Mozilla browsers like Netscape Navigator. */
-moz-opacity:0.3;


/* This is for old versions of Safari (1.x) with KHTML rendering engine */
-khtml-opacity: 0.3;


/* This is the "most important" one because it's the current standard in CSS. This will work in most versions of Firefox, Safari, and Opera. */
opacity: 0.3;
}

or just do it with jQuery:

// a crossbrowser solution
$(document).ready(function(){
$(".transparent").css('opacity','.3');
});

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To simulate RGBA and HSLA background in IE, you can use a gradient filter, with the same start and end color (alpha channel is the first pair in the value of HEX)

background: rgba(255, 255, 255, 0.3); /* browsers */
filter: progid:DXImageTransform.Microsoft.gradient(GradientType=0,startColorstr='#4cffffff', endColorstr='#4cffffff'); /* IE */

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I'm late to the party, but for anyone else who finds this - this article is very useful: http://kilianvalkhof.com/2010/css-xhtml/how-to-use-rgba-in-ie/

It uses the gradient filter to display solid but transparent colour.

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Though late, I had to use that today and found a very useful php script here that will allow you to dynamically create a png file, much like the way rgba works.

background: url(rgba.php?r=255&g=100&b=0&a=50) repeat;
background: rgba(255,100,0,0.5);

The script can be downloaded here: http://lea.verou.me/wp-content/uploads/2009/02/rgba.zip

I know it may not be the perfect solution for everybody, but it's worth considering in some cases, since it saves a lot of time and works flawlessly. Hope that helps somebody!

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this worked for me to solve the problem in IE8:

-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=1)";

Cheers

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I believe this is the best because on this page has a tool to help you generate alpha-transparent background:

"Cross browser alpha transparent background CSS (rgba)" ^{_{(*now linked to archive.org)}}

#div {
background:rgb(255,0,0);
background: transparent\9;
background:rgba(255,0,0,0.3);
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#4cFF0000,endColorstr=#4cFF0000);
zoom: 1;
}

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It is very simply you have to give first you have to give backgound as rgb because Internet Explorer 8 will support rgb instead rgba and then u have to give opacity like filter:alpha(opacity=50);

background:rgb(0,0,0);
filter:alpha(opacity=50);

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To use rgba background in IE there is a fallback.

We have to use filter property. that uses ARGB

    background:none;
-ms-filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#33ffffff,endColorstr=#33ffffff);
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#33ffffff,endColorstr=#33ffffff);
zoom: 1;

this is fallback for rgba(255, 255, 255, 0.2)

Change #33ffffff according to yours.

How to calculate `ARGB` for `RGBA`

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There are mostly all browser support RGBa code in CSS but only IE8 and below level does not support RGBa css code. For This here is solution. For The solution you must follow this code and it’s better to go with it’s sequence otherwise you will not get perfect output as you wish. This code is used by me and it’s mostly perfect. make comment if it’s perfect.

.class
{
/* Web browsers that does not support RGBa */
background: rgb(0, 0, 0);
/* IE9/FF/chrome/safari supported */
background: rgba(0, 0, 0, 0.6);
/* IE 8 suppoerted */
/* Here some time problem for Hover than you can use background color/image */
-ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#88000000, endColorstr=#88000000)";
/* Below IE7 supported */
filter: progid:DXImageTransform.Microsoft.gradient(startColorstr=#88000000, endColorstr=#88000000);
}

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This a transparency solution for most browsers including IE x

.transparent {
/* Required for IE 5, 6, 7 */
/* ...or something to trigger hasLayout, like zoom: 1; */
width: 100%;


/* Theoretically for IE 8 & 9 (more valid) */
/* ...but not required as filter works too */
/* should come BEFORE filter */
-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=50)";


/* This works in IE 8 & 9 too */
/* ... but also 5, 6, 7 */
filter: alpha(opacity=50);


/* Older than Firefox 0.9 */
-moz-opacity:0.5;


/* Safari 1.x (pre WebKit!) */
-khtml-opacity: 0.5;


/* Modern!
/* Firefox 0.9+, Safari 2?, Chrome any?
/* Opera 9+, IE 9+ */
opacity: 0.5;
}

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The best solution I found so far is the one proposed by David J Marland in his blog, to support opacity in old browsers (IE 6+):

.alpha30{
background:rgb(255,0,0); /* Fallback for web browsers that don't support RGBa nor filter */
background: transparent\9; /* backslash 9 hack to prevent IE 8 from falling into the fallback */
background:rgba(255,0,0,0.3); /* RGBa declaration for browsers that support it */
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#4cFF0000,endColorstr=#4cFF0000); /* needed for IE 6-8 */
zoom: 1; /* needed for IE 6-8 */
}


/*
* CSS3 selector (not supported by IE 6 to IE 8),
* to avoid IE more recent versions to apply opacity twice
* (once with rgba and once with filter)
*/
.alpha30:nth-child(n) {
filter: none;
}

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This solution really works, try it. Tested in IE8

.dash-overlay{
-ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#4C000000,endColorstr=#4C000000)";
}

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After searching a lot, I found the following solution which is working in my cases:

.opacity_30{
background:rgb(255,255,255); /* Fallback for web browsers that don't support neither RGBa nor filter */
background: transparent\9; /* Backslash 9 hack to prevent IE 8 from falling into the fallback */
background:rgba(255,255,255,0.3); /* RGBa declaration for modern browsers */
-ms-filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#4CFFFFFF,endColorstr=#4CFFFFFF); /* IE 8 suppoerted; Sometimes Hover issues may occur, then we can use transparent repeating background image :( */
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#4CFFFFFF,endColorstr=#4CFFFFFF); /* needed for IE 6-7 */
zoom: 1; /* Hack needed for IE 6-8 */
}


/* To avoid IE more recent versions to apply opacity twice (once with rgba and once with filter), we need the following CSS3 selector hack (not supported by IE 6-8) */
.opacity_30:nth-child(n) {
filter: none;
}

*Important: To calculate ARGB(for IEs) from RGBA, we can use online tools:

CSS 背景不透明，rgba 不能在 IE8中工作

How to calculate ARGB for RGBA

How to calculate `ARGB` for `RGBA`