PathHelper - Convert File and Folder Paths and URLs in an ASP.NET Application

string url = PathHelper.AppPath + "folder/page.aspx";

/// <summary>
/// The virtual application path:
/// "/myapp/"
/// "/apps/myapp/"
/// "/"
/// </summary>
public static string AppPath
{
	get
	{
		// get the regular application path
		string path = HttpContext.Current.Request.ApplicationPath;

		// ensure a trailing slash...
		if (path == "")
			return "/";
		if (path[path.Length-1] != '/')
			path += "/";
		return path;
	}
}

string path = TextBox1.Text.Trim();

// test whether path is a physical path
bool isPhysical = PathHelper.IsPhysicalPath(path);

// test whether path is an absolute URL path
bool isAbsolute = PathHelper.IsAbsolutePath(path);

// test whether path is a virtual URL path
bool isVirtual = PathHelper.IsVirtualPath(path);

// test whether path is application relative 
bool isApplication = PathHelper.IsApplicationPath(path);