/// <summary>
        /// Busca o parâmetro "picture" na queryString, e trata caso exista.
        /// </summary>
        /// <param name="context"></param>
        private void VerificaParametro_Picture(HttpContext context)
        {
            if (!String.IsNullOrEmpty(context.Request.QueryString["picture"]))
            {
                string fileName = UtilBO.DecodificaQueryString(context.Request.QueryString["picture"]);

                bool redimensionar = ((!String.IsNullOrEmpty(context.Request.QueryString["w"])) &&
                                      (!String.IsNullOrEmpty(context.Request.QueryString["h"])));

                try
                {
                    string folder = context.Server.MapPath("~/App_Themes");

                    FileInfo info = new FileInfo(folder + Path.DirectorySeparatorChar + fileName);

                    if (info.Directory.FullName.StartsWith(folder, StringComparison.OrdinalIgnoreCase))
                    {
                        if ((info.Exists) && IsImage(info))
                        {
                            context.Response.Cache.SetCacheability(HttpCacheability.Public);
                            context.Response.Cache.SetExpires(DateTime.Now.AddYears(1));

                            if (redimensionar)
                            {
                                int heigth = Convert.ToInt32(context.Request.QueryString["h"]);
                                int width  = Convert.ToInt32(context.Request.QueryString["w"]);

                                Image.GetThumbnailImageAbort myCallback = ThumbnailCallback;
                                Image img = Image.FromFile(info.FullName);

                                // Criando objeto redimencionado.
                                Image thumb = img.GetThumbnailImage
                                              (
                                    width,
                                    heigth,
                                    myCallback,
                                    IntPtr.Zero
                                              );

                                // ContentType sempre JPG.
                                context.Response.ContentType = "image/png";

                                // Enviando email para Response.
                                thumb.Save
                                (
                                    context.Response.OutputStream,
                                    System.Drawing.Imaging.ImageFormat.Jpeg
                                );

                                img.Dispose();
                                thumb.Dispose();
                            }
                            else
                            {
                                int    index     = fileName.LastIndexOf(".") + 1;
                                string extension = fileName.Substring(index).ToUpperInvariant();

                                // Fix for IE not handling jpg image types
                                if (string.Compare(extension, "JPG") == 0)
                                {
                                    context.Response.ContentType = "image/png";
                                }
                                else
                                {
                                    context.Response.ContentType = "image/" + extension;
                                }

                                context.Response.TransmitFile(info.FullName);
                            }

                            context.Response.Flush();
                        }
                        else
                        {
                            // Limpa o response.
                            context.Response.Flush();
                            context.Response.Clear();
                            context.ApplicationInstance.CompleteRequest();
                        }
                    }
                    else
                    {
                        context.Response.Redirect("~/Manutencao.aspx?erro=404", false);
                        context.ApplicationInstance.CompleteRequest();
                    }
                }
                catch (Exception ex)
                {
                    try
                    {
                        // Limpa o response.
                        context.Response.Flush();
                        context.Response.Clear();
                        context.ApplicationInstance.CompleteRequest();
                        ApplicationWEB._GravaErro(ex);
                    }
                    catch
                    {
                    }
                }
            }
        }