asp.net删除文本编辑器上传的图片

private string GetImg(string str)
    {
        string res = "";
        string tem = "";
        int startIndex = 0;
        int endIndex = 0;
        for (int i = 0; i < str.Length - 3; i++)
        {
            tem = str.Substring(i, 3).ToLower();
            if (tem == "src")
            {
                startIndex = i;
                str = str.Substring(startIndex+5);
                endIndex = str.IndexOf('>');
                res = str.Substring(0, endIndex-3);
                str = str.Substring(endIndex);
                res += "|"+GetImg(str); //递归调用               
                break;
            }
        }
        return res;
    }

protected void dgrdName_ItemCommand(object source, DataGridCommandEventArgs e)
    {
       
        if (e.CommandName == "Delete")
        {
            int id = Convert.ToInt32(e.CommandArgument.ToString());

            string str = "select [content] from news where id="+id+"";
            string content = DB.ReadOut2(str);
            string img=GetImg(content);
            img = img.Substring(0,img.Length-1);
            string [] arr=img.Split('|');
            for (int i = 0; i < arr.Length;i++ )
            {
              
                File.Delete(HttpContext.Current.Server.MapPath("/" + arr[i]));
             
            }
         
           string delstr = "delete  from news where id=" + id + "";
            DB.myCommand(delstr);
            DataBind();

        }
       
    }