css 3 的興起，從而讓 前端這個逐漸火了起來，越來越多的人參與研究當中。由 Font-Awesome、ionicons 為代表的網絡字體在 css 上火了起來。

以 Font-Awesome 為例：

@font-face {
  font-family: ‘FontAwesome‘;
  src: url(‘../fonts/fontawesome-webfont.eot?v=4.4.0‘);
  src: url(‘../fonts/fontawesome-webfont.eot?#iefix&v=4.4.0‘) format(‘embedded-opentype‘), url(‘../fonts/fontawesome-webfont.woff2?v=4.4.0‘) format(‘woff2‘), url(‘../fonts/fontawesome-webfont.woff?v=4.4.0‘) format(‘woff‘), url(‘../fonts/fontawesome-webfont.ttf?v=4.4.0‘) format(‘truetype‘), url(‘../fonts/fontawesome-webfont.svg?v=4.4.0#fontawesomeregular‘) format(‘svg‘)
 
;
  font-weight: normal;
  font-style: normal;
}
.fa {
  display: inline-block;
  font: normal normal normal 14px/1 FontAwesome;
  font-size: inherit;
  text-rendering: auto;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
.fa-flag:before {
  content: "\f024";
}

通過在頁面上 <i class="fa fa-flag"></i> 就可以得到

找到 fontawesome-webfont.ttf 這個文件，用 FontLab Studio 打開

原理原來這麽簡單。

一、TureTpe(.ttf)格式：

.ttf字體是Windows和Mac的最常見的字體，是一種RAW格式，因此他不為網站優化,支持這種字體的瀏覽器有【IE9+,Firefox3.5+,Chrome4+,Safari3+,Opera10+,iOS Mobile Safari4.2+】；

二、OpenType(.otf)格式：

.otf字體被認為是一種原始的字體格式，其內置在TureType的基礎上，所以也提供了更多的功能,支持這種字體的瀏覽器有【Firefox3.5+,Chrome4.0+,Safari3.1+,Opera10.0+,iOS Mobile Safari4.2+】；

三、Web Open Font Format(.woff)格式：

.woff字體是Web字體中最佳格式，他是一個開放的TrueType/OpenType的壓縮版本，同時也支持元數據包的分離,支持這種字體的瀏覽器有【IE9+,Firefox3.5+,Chrome6+,Safari3.6+,Opera11.1+】；

四、Embedded Open Type(.eot)格式：

.eot字體是IE專用字體，可以從TrueType創建此格式字體,支持這種字體的瀏覽器有【IE4+】；

五、SVG(.svg)格式：

.svg字體是基於SVG字體渲染的一種格式,支持這種字體的瀏覽器有【Chrome4+,Safari3.1+,Opera10.0+,iOS Mobile Safari3.2+】。

下面再看看 weui 裏面的圖標是怎麽實現的

@font-face {
    font-weight: 400;
    font-style: normal;
    font-family: weui;
    src: 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) format(‘truetype‘);
}

除了 src 其他都一樣， 想要看這個字體文件，首先需要 下載下來，怎麽下載呢？其實很簡單

把這個請求的內容到瀏覽器請求以下，會自動下載一個 不帶任何擴展名的文件， 通過它的 src 最後的 format 格式可以知道是 ttf 格式，我把它下載下來後保存為 1.ttf，然後用 FontLab Studio 打開

網絡字體原理