如何检测 Unicode 字符是否在我的 web 页面上正确显示？

Question

I'm trying to use a reasonably esoteric Unicode character on a website — specifically “︙”. Windows XP, as far as I know, didn't ship with a font that included a glyph for this character — the Virtual PC IE 6 test image doesn't display it at any rate.

Is there any way I can detect whether the character is displaying properly, in case people are looking at the site using Windows XP without Arial Unicode MS installed?

An answer on a similar question suggested comparing the width of an element containing just this character with the width of an element containing an unprintable Unicode character. Unfortunately, both seem to render at the same width in browsers that display my character properly as well.

Answer 1

Try using ⋮ ( ⋮ ), which is an alternate character for the same thing (a vertical ellipsis). I'm not sure why there are two glyphs for this, and they are slightly different; in my own testing, ︙ ( ︙ ) uses circles for the dots, while the other one uses squares. That probably varies by font though. And anyway, you have to increase the font size to ridiculous sizes to notice a difference.

Answer 2

What you are trying to do is virtually impossible, at least not in a safe way .

Instead you should clearly define your supported audience, specifying exactly what browsers you will support and for unsupported ones display an warning.

BTW, Do not display the warning for any browser that it was not identified by you, just for the that were identified as bad.

You could add an embedded font but this will work only on some browsers and probably not on mobile devices. I wouldn't recommend you to use such esoteric characters.

One idea http://www.devslide.com/labs/browser-detection

NOTE : in the text above, I refer to a browser as a combination of browser and operating system. Today most browsers do properly display Unicode characters, BUT the fonts do not, and the user will see boxes instead of correct characters. A well designed web page must render properly with the default fonts existing on the client computer.

Answer 3

Use an embeded font. You have to have 4 versions or so of the font file around for it to work in all browsers, but it works in IE6 Up and all modern browsers, including iOS mobile devices..

http://www.fontsquirrel.com/fontface/generator

You can upload a TTF font and get the whole package back as a download - all the font files needed and the CSS plus a sample page to test with. I have not found a browser that this will not work in (including 1-2 version back from current, depending on the browser).

Answer 4

I am not sure you need to worry about this... according to the Microsoft site, Arial Unicode MS is automatically installed for Windows XP.

http://office.microsoft.com/en-us/visio-help/install-the-universal-font-for-unicode-HP005255840.aspx