为带有版本标签的 ASP MVC Bundle 使用 CDN

Question

我想将 CDN 与我的 Bundle 一起使用，但 ASP MVC 不能原生处理 CDN url 的版本。

例如：

public static void RegisterBundles(BundleCollection bundles)
{
    bundles.UseCdn = true;   //enable CDN support

    //add link to jquery on the CDN
    var jqueryCdnPath = 
        "http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.7.1.min.js";

    bundles.Add(new ScriptBundle("~/bundles/jquery",
                jqueryCdnPath).Include(
                "~/Scripts/jquery-{version}.js"));
}

我不能使用{version} 标签在jqueryCdnPath 内，Framewok 无法知道我想要远程 url 中的本地版本。 有没有办法解决这个限制？如何检索本地版本来构建 CDN url？

Answer 1

我有一个选项，但它仅在 virtualPath 中使用 {version} 标记时才有效。一些脚本（bootstrap、globalize...）不需要版本标签，而且我无法知道要在 CDN 上引用的版本号。

private static string GetLastIncludedVirtualPath(this Bundle bundle)
{
  var files = bundle.EnumerateFiles(new BundleContext(new HttpContextWrapper(HttpContext.Current), new BundleCollection(), ""));
  var lastFile = files.LastOrDefault();
  if (lastFile == null)
    throw new InvalidOperationException("You must include a file so version can be extracted");
  return lastFile.IncludedVirtualPath;
}

public static Bundle IncludeWithVersionnedCdn(this Bundle bundle, string virtualPath, string cdnPath, params IItemTransform[] transforms)
{
  if (bundle == null)
    throw new ArgumentNullException("bundle");
  if (cdnPath == null)
    throw new ArgumentNullException("cdnPath");
  bundle.Include(virtualPath, transforms);
  //GetVersion
  int lengthBeforeVersion = virtualPath.IndexOf("{version}", StringComparison.OrdinalIgnoreCase);
  if (lengthBeforeVersion == -1)
    throw new ArgumentException("Path must contains {version} when version argument is not specified", "virtualPath");
  var includedPath = bundle.GetLastIncludedVirtualPath();
  int lengthAfterVersion = virtualPath.Length - lengthBeforeVersion - "{version}".Length;
  string version = includedPath.Remove(includedPath.Length - lengthAfterVersion).Substring(lengthBeforeVersion);
  //Set CDN
  bundle.CdnPath = cdnPath.Replace("{version}", version);
  return bundle;
}

用法：

bundles.Add(new ScriptBundle("~/bundles/jquery")
                .IncludeWithVersionnedCdn(
                    "~/Scripts/jquery-{version}.js",
                    "//ajax.aspnetcdn.com/ajax/jQuery/jquery-{version}.min.js"));