https://cubegao.com/tags/%E6%BA%90%E7%A0%81/ Recent content in 源码 on cubegao Hugo zh-CN Thu, 02 Nov 2017 18:51:00 +0800 https://cubegao.com/post/2017-11-02-sdwebimage/ Thu, 02 Nov 2017 18:51:00 +0800 https://cubegao.com/post/2017-11-02-sdwebimage/ <p>###背景 <code>SDWebImage</code>是<code>iOS</code>开发过程中最常使用的一个网络图片库，包括图片的下载和缓存。</p> <p>主要提供的功能如下：</p> <p>1.提供<code>UIImageView</code>, <code>UIButton</code>,<code> MKAnnotationView</code> 的分类，用来加载网络图片，并进行缓存管理; 2.异步方式来下载网络图片 3.异步方式: <code>memory</code> (内存)＋ <code>disk</code> (磁盘) 来缓存网络图片，<code>LRU</code>自动管理缓存; 4.后台图片解码,转换及压缩; 5.同一个 <code>URL</code> 不会重复下载; 6.失效的 <code>URL</code> 不会被无限重试; 7.支持 <code>GIF</code>动画 及<code> WebP</code> 格式; 8.使用 <code>GCD </code>和 <code>ARC</code>; 9.开启子线程进行耗时操作，不阻塞主线程;</p> <p>###入口部分 在使用<code>SDWebImage</code>的时候，入口如下：</p> <div class="goat svg-container "> <svg xmlns="http://www.w3.org/2000/svg" font-family="Menlo,Lucida Console,monospace" viewBox="0 0 600 41" > <g transform='translate(8,16)'> <text 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style='font-size:1em'>;</text> </g> </svg> </div> <p>点进去，可以看到下面这些方法：</p>