C#根据网址获取域名,目录名,文件名函数

#region 获取网址中域名,目录,文件名的函数

 public string GetUrlDomainName(string strHtmlPagePath)
 {
            string p = @"http://[^\.]*\.(?<domain>[^\.]*)";
            Regex reg = new Regex(p, RegexOptions.IgnoreCase);
            Match m = reg.Match(HostUrl);
            Result=m.Groups["domain"].Value;

 }

 public string GetUrlDomainName(string strHtmlPagePath)
 {
            string p = @"(?<=http://)[\w\.]+[^/]";　
            Regex reg = new Regex(p, RegexOptions.IgnoreCase);
            Match m = reg.Match(strHtmlPagePath);
            return m.Groups[0].Value;
 }

  public string[] GetUrlFolerName(string strHtmlPagePath)
  {
   //抓取网址字符串中的文件目录
 
   int at = 0;
   int start = 0;
   int notei=0;
   int endi=0;
   int[] myIntArray =new int[10];
   string[] ArrayFolderName=null;
   string NewFolderName;
   while((start < strHtmlPagePath.Length) && (at > -1))
   {
    at = strHtmlPagePath.IndexOf('/', start);
    if (at == -1) break;   
    myIntArray[notei]=at;
    start = at+1;
    notei = notei+1;
    endi=at;
   }
   ArrayFolderName=new string[notei-1];
   for(int i=0;i<notei;i++)
   {    
    if(myIntArray[i]>0)
    {
     if (myIntArray[i+1]>0)
     {
      NewFolderName=strHtmlPagePath.Substring(myIntArray[i]+1,myIntArray[i+1]-myIntArray[i]-1);      
      ArrayFolderName.SetValue(NewFolderName,i);
     }   

    }
   }
   return ArrayFolderName;  
  }

  public string GetUrlFileName(string strHtmlPagePath) 
  {
   //抓取网址字符串中的文件名称
   int at = 0;
   int start = 0;
   int notei=0;
   int endi=0;
   int[] myIntArray = new int[10]; 
   string NewFileName="";
   while((start < strHtmlPagePath.Length) && (at > -1))
   {
    at = strHtmlPagePath.IndexOf('/', start);
    if (at == -1) break;   
    myIntArray[notei]=at;
    start = at+1;
    notei = notei+1;
    endi=at;
   }

   for(int i=0;i<notei;i++)
   {   
    if(myIntArray[i]>0)
    {
     if (myIntArray[i+1]==0)
     {
      NewFileName=strHtmlPagePath.Substring(myIntArray[i]+1,strHtmlPagePath.Length-myIntArray[i]-1);
      
     }
    }
   }
   return NewFileName.ToLower();
  
  }

  #endregion