/// <summary>
/// 根据给出的相对地址获取网站绝对地址
/// </summary>
/// <param name="localPath">相对地址</param>
/// <returns>绝对地址</returns>
public static string GetWebPath(string localPath)
{
  string path = HttpContext.Current.Request.ApplicationPath;
  string thisPath;
  string thisLocalPath;
  //如果不是根目录就加上"/" 根目录自己会加"/"
  if (path != "/")
  {
 thisPath = path + "/";
  }
  else
  {
 thisPath = path;
  }
  if (localPath.StartsWith("~/"))
  {
 thisLocalPath = localPath.Substring(2);
  }
  else
  {
 return localPath;
  }
  return thisPath + thisLocalPath;
}