public static IWebPageLocator CreateLocator(string extension)
{
IWebPageLocator locator = WebPagesConfiguration.Global.PageConfig.GetPageLocator(extension); //优先从配置中读取
if (locator != null)
{
return(locator);
}
if (_locators.TryGetValue(extension, out locator))
{
return(locator);
}
//由于是静态方法，要保证线程安全，所以锁定，再读取
lock (_locators)
{
if (_locators.TryGetValue(extension, out locator))
{
return(locator);
}
}
return(WebPageTypeLocatorEmpty.Instance);
}
public IAspect[] CreateAspects(WebPageContext context)
{
IWebPageLocator locator = WebPageLocatorFactory.CreateLocator(context.PathExtension);
var aspects = locator.GetAspects(context.VirtualPath);
if (aspects == null)
{
if (!context.IsValidPath())
{
//如果既没有后台文件，也没有前台文件，那么资源不存在
throw new HttpException(404, string.Format(Strings.RequestResourceNotExist, context.VirtualPath));
}
aspects = locator.GetDefaultAspects(); //如果有前台文件那么用默认的处理
}
return(aspects);
}
/// <summary>
/// 注册页面类型定位器，请保证<paramref name="locator"/>是单例的
/// </summary>
/// <param name="locator"></param>
public static void RegisterLocator(string extension, IWebPageLocator locator)
{
if (!_locators.ContainsKey(extension))
{
lock (_locators)
{
if (!_locators.ContainsKey(extension))
{
if (extension.StartsWith("."))
{
extension = extension.Substring(1);
}
_locators.Add(extension, locator);
_locators.Add(string.Format(".{0}", extension), locator);
}
}
}
}
private static WebPage CreatePage(WebPageContext context)
{
IWebPageLocator locator = WebPageLocatorFactory.CreateLocator(context.PathExtension);
IHttpHandler handler = locator.GetHandler(context.VirtualPath);//利用资源定位器得到资源的Handler类型
if (handler == null)
{
if (!context.IsValidPath())
{
//如果既没有后台文件，也没有前台文件，那么资源不存在
throw new HttpException(404, string.Format(Strings.RequestResourceNotExist, context.VirtualPath));
}
handler = locator.GetDefaultHandler(); //如果有前台文件那么用默认的处理
}
WebPage page = handler as WebPage;
if (page == null)
{
throw new TypeMismatchException(handler.GetType(), typeof(WebPage));
}
return(page);
}
