Is there a way to set background-image as a base64

2019-01-17 13:42发布

I want to change background dynamically in JS and my set of images is in base64 encoded. I try:

document.getElementById("bg_image").style.backgroundImage = 
   "url('http://amigo.com/300107-2853.jpg')"; 

with perfect result,

yet I fail to do the same with:

document.getElementById("bg_image").style.backgroundImage = 
   "url('data:image/png;base64,iVBORw0KGgoAAAAAAAAyCAYAAAAUYybjAAAgAElE...')";

nor

document.getElementById("bg_image").style.backgroundImage = 
   "data:image/png;base64,iVBORw0KGgoAAAAAAAAyCAYAAAAUYybjAAAgAElE...";

Is there any way to do it?

8条回答
趁早两清
2楼-- · 2019-01-17 14:22

This is the correct way to make a pure call. No CSS.

<div style='background:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABwAAAAFCAYAAABW1IzHAAAAHklEQVQokWNgGPaAkZHxPyMj439sYrSQo51PBgsAALa0ECF30JSdAAAAAElFTkSuQmCC)repeat-x center;'></div>
查看更多
倾城 Initia
3楼-- · 2019-01-17 14:23

What I usually do, is to store the full string into a variable first, like so:

<?php
$img_id = 'data:image/png;base64,iVBORw0KGgoAAAAAAAAyCAY...';
?>

Then, where I want either JS to do something with that variable:

<script type="text/javascript">
document.getElementById("img_id").backgroundImage="url('<?php echo $img_id; ?>')";
</script>

You could reference the same variable via PHP directly using something like:

<img src="<?php echo $img_id; ?>">

Works for me ;)

查看更多
地球回转人心会变
4楼-- · 2019-01-17 14:28

I tried to do the same as you, apparently is the backgroundImage doesn't work with enconded data. As an alternative I suggest to use css classes and the change between those classes.

If you are generating the data "on the fly" you can load the css files dynamically.

CSS:

.backgroundA {
    background-image: url(" data:image/png;base64,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");
}

.backgroundB {
background-image:url("data:image/gif;base64,R0lGODlhUAAPAKIAAAsLav///88PD9WqsYmApmZmZtZfYmdakyH5BAQUAP8ALAAAAABQAA8AAAPbWLrc/jDKSVe4OOvNu/9gqARDSRBHegyGMahqO4R0bQcjIQ8E4BMCQc930JluyGRmdAAcdiigMLVrApTYWy5FKM1IQe+Mp+L4rphz+qIOBAUYeCY4p2tGrJZeH9y79mZsawFoaIRxF3JyiYxuHiMGb5KTkpFvZj4ZbYeCiXaOiKBwnxh4fnt9e3ktgZyHhrChinONs3cFAShFF2JhvCZlG5uchYNun5eedRxMAF15XEFRXgZWWdciuM8GCmdSQ84lLQfY5R14wDB5Lyon4ubwS7jx9NcV9/j5+g4JADs=");
}

HTML:

<div id="test" height="20px" class="backgroundA"> div test 1
</div>
<div id="test2" name="test2" height="20px" class="backgroundB"> div test2
</div>
<input type="button" id="btn" />

Javascript:

 function change()
{
    if (document.getElementById("test").className =="backgroundA")
    {
        document.getElementById("test").className="backgroundB";
    document.getElementById("test2").className="backgroundA";
    }
    else
    {
        document.getElementById("test").className="backgroundA";
    document.getElementById("test2").className="backgroundB";

    }
}

btn.onclick= change;

I fiddled it here, press the button and it will switch the divs' backgrounds: http://jsfiddle.net/egorbatik/fFQC6/

查看更多
贼婆χ
5楼-- · 2019-01-17 14:32

In my case, it was just because I didn't set the height and width.

But there is another issue.

The background image could be removed using

element.style.backgroundImage=""

but couldn't be set using

element.style.backgroundImage="some base64 data"

Jquery works fine.

查看更多
Evening l夕情丶
6楼-- · 2019-01-17 14:36

Had the same problem with base64. For anyone in the future with the same problem:

url = "data:image/png;base64,iVBORw0KGgoAAAAAAAAyCAYAAAAUYybjAAAgAElE...";

This would work executed from console, but not from within a script:

$img.css("background-image", "url('" + url + "')");

But after playing with it a bit, I came up with this:

var img = new Image();
img.src = url;
$img.css("background-image", "url('" + img.src + "')");

No idea why it works with a proxy image, but it does. Tested on Firefox Dev 37 and Chrome 40.

Hope it helps someone.

EDIT

Investigated a little bit further. It appears that sometimes base64 encoding (at least in my case) breaks with CSS because of line breaks present in the encoded value (in my case value was generated dynamically by ActionScript).

Simply using e.g.:

$img.css("background-image", "url('" + url.replace(/(\r\n|\n|\r)/gm, "") + "')");

works too, and even seems to be faster by a few ms than using a proxy image.

查看更多
爷的心禁止访问
7楼-- · 2019-01-17 14:37

Try this, I have got success response ..it's working

$("#divId").css("background-image", "url('data:image/png;base64," + base64String + "')");
查看更多
登录 后发表回答