title: How to use bundle transformer to Minify CSS or JS
body: <p>I want to use bundle transformer to bundle and minify my css collection
  , but however i tried it doesn't work</p>
  
  <p>heres my code, please give me some advise, thanks.</p>
  
  <pre><code>        var nullBuilder = new NullBuilder();
          var cssTransformer = new StyleTransformer(new CleanCssMinifier());
          var nullOrderer = new NullOrderer();
  
          BundleResolver.Current = new CustomBundleResolver();
  
          var commonStylesBundle = new Bundle("~/bundles/css/site");
          commonStylesBundle.IncludeDirectory("~/Content/sass", "*.css");
  
          commonStylesBundle.Builder = nullBuilder;
          commonStylesBundle.Transforms.Add(cssTransformer);
          commonStylesBundle.Orderer = nullOrderer;
  
          bundles.Add(commonStylesBundle);
  </code></pre>
  
  <p>it always output the html like this:</p>
  
  <pre><code>&lt;link href="/Content/sass/card.css?bundleVirtualPath=%7e%2fbundles%2fcss%2fsite" rel="stylesheet"/&gt;
  &lt;link href="/Content/sass/header.css?bundleVirtualPath=%7e%2fbundles%2fcss%2fsite" rel="stylesheet"/&gt;
  &lt;link href="/Content/sass/login.css?bundleVirtualPath=%7e%2fbundles%2fcss%2fsite" rel="stylesheet"/&gt;
  </code></pre>