System.Web.UI.Control.GetPhysicalFilePath C# (CSharp) Method

		internal string GetPhysicalFilePath (string virtualPath)
		{
			Page page = Page;

			if (VirtualPathUtility.IsAbsolute (virtualPath))
				return page != null ? page.MapPath (virtualPath) : Context.Server.MapPath (virtualPath);

			// We need to determine whether one of our parents is a
			// master page. If so, we need to map the path
			// relatively to the master page and not our containing
			// page/control. This is necessary for cases when a
			// relative path is used in a control placed in a master
			// page and the master page is referenced from a
			// location other than its own. In such cases MS.NET looks
			// for the file in the directory where the master page
			// is.
			//
			// An example of where it is needed is at
			//
			// http://quickstarts.asp.net/QuickStartv20/aspnet/samples/masterpages/masterpages_cs/pages/default.aspx
			//
			MasterPage master = null;
			Control ctrl = Parent;

			while (ctrl != null) {
				if (ctrl is MasterPage) {
					master = ctrl as MasterPage;
					break;
				}
				ctrl = ctrl.Parent;
			}

			string path;
			if (master != null)
				path = VirtualPathUtility.Combine (master.TemplateSourceDirectory + "/", virtualPath);
			else
				path = VirtualPathUtility.Combine (TemplateSourceDirectory + "/", virtualPath);
			
			return page != null ? page.MapPath (path) : Context.Server.MapPath (path);
		}