Using an Data URI SVG as a CSS background image

问题

Backstory:

• Goal: create a triangular shadow that can be applied via CSS and is scale-independant (i.e. a vector, not a raster image)
• After much research (tho I'm certainly open to alternatives) I chose to use an SVG background image as a data uri (to avoid the extra HTTP request).
• I know that this can work: http://jsfiddle.net/6WAtQ/

Where I'm stuck:

• I created a simple svg triangle, with a Gaussian blur effect, if it's written directly in the HTML (as opposed to the CSS) the svg works perfectly: http://jsfiddle.net/RAKWB/

  <svg class="shadow" xmlns="http://www.w3.org/2000/svg" version="1.1"> <defs> <filter id="f1"> <feGaussianBlur in="SourceGraphic" stdDeviation="5" /> </filter> </defs> <polygon points="200,0 200,200 0,200" filter="url(#f1)"/> </svg>​

• So I tried to replicate the above ( http://jsfiddle.net/6WAtQ/ ) using my own triangle svg,

• I replaced the hash signs with '%23', but no dice

• It's not working: http://jsfiddle.net/ZPWxK/1/

  body { background-image: url("data:image/svg+xml;utf8,data:image/svg+xml;utf8,<svg class="shadow" xmlns="http://www.w3.org/2000/svg" version="1.1"><defs><filter id="f1"><feGaussianBlur in="SourceGraphic" stdDeviation="5" /></filter></defs><polygon points="200,0 200,200 0,200" filter="url(%23f1)"/></svg>"); }

Thoughts?

回答1:

See how the working fiddle has double quotes just inside the url() and then all the SVG content uses single quotes? You need to do the same. Otherwise the parser doesn't know where the url content ends.

Alternatively you could make the url use single quotes and keep your SVG content the same.

body { background-image: url('data:image/svg+xml;utf8,<svg class="shadow" xmlns="http://www.w3.org/2000/svg" version="1.1"><defs><filter id="f1"><feGaussianBlur in="SourceGraphic" stdDeviation="5" /></filter></defs><polygon points="200,0 200,200 0,200" filter="url(%23f1)"/></svg>'); }

回答2:

You can also use a base64 encoding for a cleaner format, even if it increase the actual SVG file size. See also css-tricks.com post.

i.e.:

background: url('data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIy NCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0Ij4KICAgIDxwYXRoIGQ9 Ik0wIDBoMjR2MjRoLTI0eiIgZmlsbD0ibm9uZSIvPgogICAgPHBhdGggZD0iTTEw LjA5IDE1LjU5bDEuNDEgMS40MSA1LTUtNS01LTEuNDEgMS40MSAyLjU4IDIuNTlo LTkuNjd2Mmg5LjY3bC0yLjU4IDIuNTl6bTguOTEtMTIuNTloLTE0Yy0xLjExIDAt MiAuOS0yIDJ2NGgydi00aDE0djE0aC0xNHYtNGgtMnY0YzAgMS4xLjg5IDIgMiAy aDE0YzEuMSAwIDItLjkgMi0ydi0xNGMwLTEuMS0uOS0yLTItMnoiLz4KPC9zdmc+ Cg==');

You can use this bash command (tested on MacOS X) to easily generate the CSS background property:

echo "background: url('data:image/svg+xml;base64,"$(openssl base64 < Downloads/material-design-icons-1.0.0/action/svg/ic_exit_to_app_24px.svg)"');"

回答3:

Make sure to percent-encoding in data URI not encoded with base64.

For example, for an SVG, encode like this:

body { 
  background-image: url('data:image/svg+xml;utf8,%3Csvg%20class%3D%22shadow%22%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20version%3D%221.1%22%3E%3Cpolygon%20style%3D%22stroke%3A%23252423%3Bfill%3A%23252423%3B%22%20points%3D%220%2C200%200%2C0%20200%2C0%22%2F%3E%3C%2Fsvg%3E'); 
}

This is equivalent to the following SVG:

<svg class="shadow" xmlns="http://www.w3.org/2000/svg" version="1.1"><polygon style="stroke:#252423;fill:#252423;" points="0,200 0,0 200,0"/></svg>

To percent encode an image, you can use the following JavaScript code:

console.log(encodeURIComponent('<svg class="shadow" xmlns="http://www.w3.org/2000/svg" version="1.1"><polygon style="stroke:#252423;fill:#252423;" points="0,200 0,0 200,0"/></svg>'))

来源：https://stackoverflow.com/questions/13742934/using-an-data-uri-svg-as-a-css-background-image