Sending the contents of a webpage with images as an HTML mail

<br />
using System;<br />
using System.Collections.Generic;<br />
using System.Text;<br />
using System.Net.Mail;<br />
using System.Net;<br />
using System.IO;<br />
<br />
namespace Framework.Web<br />
{<br />
<br />
    // How to use ... Reference URL : http://www.codeproject.com/cs/internet/Mail_Webpage_with_images.asp<br />
    //// The contents that will be sent<br />
    //Uri uri = new Uri("http://about.com/");<br />
<br />
    //// Configuration of the email message<br />
    //Fmd.Mail.WebpageMailer mailer = new Fmd.Mail.WebpageMailer();<br />
    //mailer.SmtpServerName = "mail.somesmptserver.com";<br />
    //mailer.Delay = 0;<br />
    //mailer.MailMessage.From = new MailAddress("noreply@somedomain.com");<br />
    //mailer.MailMessage.To.Add(new MailAddress("recipient@somedomain.com"));<br />
    //mailer.MailMessage.Subject = "Automatic Mail Message " + <br />
    //                             DateTime.Now.ToShortDateString();<br />
    //mailer.MailMessage.Priority = MailPriority.Normal;<br />
    //mailer.SmtpServerPassword = "somesmtppassword";<br />
    //mailer.SmtpServerUserName = "somesmtpusername";<br />
<br />
    //// Sending the webpage<br />
    //mailer.SendMailMessage(uri);<br />
<br />
    public class WebpageMailer<br />
    {<br />
        MailMessage _mailMessage = new MailMessage();<br />
        public MailMessage MailMessage<br />
        {<br />
            get<br />
            {<br />
                return _mailMessage;<br />
            }<br />
        }<br />
<br />
        string _smptServerName;<br />
        public string SmtpServerName<br />
        {<br />
            get { return _smptServerName; }<br />
            set { _smptServerName = value; }<br />
        }<br />
<br />
        string _smptServerUserName;<br />
        public string SmtpServerUserName<br />
        {<br />
            get { return _smptServerUserName; }<br />
            set { _smptServerUserName = value; }<br />
        }<br />
<br />
<br />
        string _smptServerPassword;<br />
        public string SmtpServerPassword<br />
        {<br />
            get { return _smptServerPassword; }<br />
            set { _smptServerPassword = value; }<br />
        }<br />
<br />
<br />
       <br />
<br />
        int _delay;<br />
        /// <summary><br />
        /// The delay can be used to relieve stress from a webserver<br />
        /// It is the number of milliseconds that the application waits before retrieving the next image<br />
        /// </summary><br />
        public int Delay<br />
        {<br />
            get { return _delay; }<br />
            set { _delay = value; }<br />
        }<br />
<br />
        /// <summary><br />
        /// Sends the contents of the uri as a mailmessage<br />
        /// The mail message should be configured first with recipient atc...<br />
        /// </summary><br />
        /// <param name="uri"></param><br />
        public void SendMailMessage(Uri uri)<br />
        {<br />
            // Retrieve the contents<br />
            string htmlbody = GetBody(uri);<br />
<br />
            // See what images there are to embed<br />
            string modifiedbody;<br />
            List<LinkedResource> foundResources;<br />
            ExtractLinkedResources(uri, htmlbody, out modifiedbody, out foundResources);<br />
<br />
            // Write the html to a memory stream<br />
            MemoryStream stream = new MemoryStream();<br />
            byte[] bytes = System.Text.Encoding.ASCII.GetBytes(modifiedbody);<br />
            stream.Write(bytes, 0, bytes.Length);<br />
            stream.Position = 0;<br />
<br />
            // Configure the mail so it contains the html page<br />
            _mailMessage.Body = "This is a html mail - use an email client that can read it";<br />
            AlternateView altView = new AlternateView(stream, System.Net.Mime.MediaTypeNames.Text.Html);<br />
<br />
            // Embed the images into the mail<br />
            foreach (LinkedResource linkedResource in foundResources)<br />
            {<br />
                altView.LinkedResources.Add(linkedResource);<br />
            }<br />
            _mailMessage.AlternateViews.Add(altView);            <br />
<br />
            // Send the mail<br />
            SmtpClient client = new SmtpClient(_smptServerName);<br />
            <br />
            if (((_smptServerUserName != null) && (_smptServerPassword != null)) && ((_smptServerUserName.Length > 0) && (_smptServerPassword.Length > 0)))<br />
            {<br />
                NetworkCredential nc = new NetworkCredential(_smptServerUserName, _smptServerPassword);<br />
                client.Credentials = nc;<br />
            }<br />
<br />
            client.Send(_mailMessage);<br />
        }<br />
<br />
        /// <summary><br />
        /// Gets the body of the mail message<br />
        /// </summary><br />
        /// <param name="uri"></param><br />
        /// <returns></returns><br />
        public static string GetBody(Uri uri)<br />
        {<br />
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);<br />
<br />
            // Set some reasonable limits on resources used by this request<br />
            request.MaximumAutomaticRedirections = 4;<br />
            request.MaximumResponseHeadersLength = 4;<br />
            // Set credentials to use for this request.<br />
            request.Credentials = CredentialCache.DefaultCredentials;<br />
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();<br />
<br />
            // Get the stream associated with the response.<br />
            Stream receiveStream = response.GetResponseStream();<br />
<br />
            // Pipes the stream to a higher level stream reader with the required encoding format. <br />
            StreamReader readStream = new StreamReader(receiveStream, Encoding.UTF8);<br />
<br />
            string body = readStream.ReadToEnd();<br />
            readStream.Close();<br />
<br />
            response.Close();<br />
            return body;<br />
        }<br />
<br />
        /// <summary><br />
        /// Retrieves an image to embed<br />
        /// </summary><br />
        /// <param name="uri"></param><br />
        /// <param name="contentType"></param><br />
        /// <returns></returns><br />
        Stream GetImageStream(Uri uri, out string contentType)<br />
        {<br />
            System.Threading.Thread.Sleep(_delay);<br />
<br />
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);<br />
<br />
            // Set some reasonable limits on resources used by this request<br />
            request.MaximumAutomaticRedirections = 4;<br />
            request.MaximumResponseHeadersLength = 4;<br />
            // Set credentials to use for this request.<br />
            request.Credentials = CredentialCache.DefaultCredentials;<br />
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();<br />
<br />
            // Get the stream associated with the response.<br />
            Stream receiveStream = response.GetResponseStream();<br />
<br />
            BinaryReader binaryReader = new BinaryReader(receiveStream);<br />
            MemoryStream memoryStream = new MemoryStream();<br />
            try<br />
            {<br />
                while (true)<br />
                {<br />
                    byte b = binaryReader.ReadByte(); // Not so efficient but it works...<br />
                    memoryStream.WriteByte(b);<br />
                }<br />
            }<br />
            catch (EndOfStreamException)<br />
            {<br />
                memoryStream.Position = 0;<br />
            }<br />
<br />
            contentType = response.ContentType;<br />
            response.Close();<br />
            return memoryStream;<br />
        }<br />
<br />
        private void ExtractLinkedResources(Uri uri, string html, out string modifiedhtml, out List<LinkedResource> linkedResources)<br />
        {<br />
            modifiedhtml = html;<br />
            linkedResources = new List<LinkedResource>();<br />
<br />
            List<string> imageNames = ExtractImageNames(html);<br />
<br />
            int imageID = 1;<br />
<br />
            foreach (string imageName in imageNames)<br />
            {<br />
                try<br />
                {<br />
                    // Deal with some escape characters that can occur in dynamic image url's<br />
                    string workaroundImageName = imageName.Replace("&", "&");<br />
<br />
                    // Generate the uri to retrieve the image - usually an image path is relative to the page uri<br />
                    Uri imageUri = new Uri(uri, workaroundImageName);<br />
<br />
                    // Retrieve the image<br />
                    string contentType;<br />
                    Stream imageStream = GetImageStream(imageUri, out contentType);<br />
<br />
                    // Fill the linked resource<br />
                    LinkedResource data = new LinkedResource(imageStream);<br />
<br />
                    // Determine a name and set the media type of the linked resource<br />
                    string generatedName = null;<br />
                    if (contentType.ToLower().IndexOf("image/gif") >= 0)<br />
                    {<br />
                        data.ContentType.MediaType = System.Net.Mime.MediaTypeNames.Image.Gif;<br />
                        generatedName = "image" + imageID.ToString() + ".gif";<br />
                    }<br />
                    else if (contentType.ToLower().IndexOf("image/jpeg") >= 0)<br />
                    {<br />
                        data.ContentType.MediaType = System.Net.Mime.MediaTypeNames.Image.Jpeg;<br />
                        generatedName = "image" + imageID.ToString() + ".jpeg";<br />
                    }<br />
<br />
                    // it is something that I don't handle yet<br />
                    if (generatedName == null)<br />
                        continue;<br />
<br />
                    // Generate the linked resource for the image being embedded<br />
                    string generatedSrc = "cid:" + generatedName;<br />
                    data.ContentType.Name = generatedName;<br />
                    data.ContentId = generatedName;<br />
                    data.ContentLink = new Uri(generatedSrc);<br />
                    linkedResources.Add(data);<br />
<br />
                    // Let the html refer to the linked resource<br />
                    modifiedhtml = modifiedhtml.Replace(imageName, generatedSrc);<br />
                }<br />
                catch<br />
                {<br />
                    modifiedhtml = modifiedhtml.Replace(imageName, "#");<br />
                }<br />
<br />
                imageID++;<br />
            }<br />
        }<br />
<br />
        /// <summary><br />
        /// longest length first<br />
        /// </summary><br />
        private class LengthComparer : IComparer<string><br />
        {<br />
            public int Compare(string x, string y)<br />
            {<br />
                return -x.Length.CompareTo(y.Length);<br />
            }<br />
        }<br />
<br />
        /// <summary><br />
        /// Sorts the list of strings so the longest names are in the start of the list<br />
        /// When there is an image named "a.aspx?id=1" and another named "a.aspx?id=12", the list should start with "a.aspx?id=12"<br />
        /// This guarantees that string replacement will not damage the names<br />
        /// </summary><br />
        /// <param name="input"></param><br />
        /// <returns></returns><br />
        static private List<string> SortNoDuplicate(List<string> input)<br />
        {<br />
            List<string> result = new List<string>(input);<br />
            IComparer<string> comparer = new LengthComparer();<br />
            result.Sort(comparer);<br />
            return result;<br />
        }<br />
<br />
        /// <summary><br />
        /// Optimistic search for image names in an html document<br />
        /// The images found here will be embedded into the email<br />
        /// </summary><br />
        /// <param name="html"></param><br />
        /// <returns></returns><br />
        private static List<string> ExtractImageNames(string html)<br />
        {<br />
            List<string> imagenames = new List<string>();<br />
            string[] imageattributes = new string[] { "src=", "background=" };<br />
            foreach (string imageattribute in imageattributes)<br />
            {<br />
                int position = 0;<br />
                while (position < html.Length)<br />
                {<br />
                    int foundIndex = html.ToLower().IndexOf(imageattribute, position);<br />
                    if (foundIndex < 0)<br />
                    {<br />
                        position = html.Length;<br />
                    }<br />
                    else<br />
                    {<br />
                        int valueStartIndex = foundIndex + imageattribute.Length + 1;<br />
                        int foundIndexEnd = html.IndexOfAny(new char[] { '\"', ' ', '\'', '>' }, valueStartIndex);<br />
                        if (foundIndexEnd < 0)<br />
                        {<br />
                            position = html.Length;<br />
                        }<br />
                        else<br />
                        {<br />
                            string relativeimagename = html.Substring(valueStartIndex, foundIndexEnd - valueStartIndex);<br />
                            relativeimagename = relativeimagename.Trim(new char[] { '\"', ' ', '\'', '>' });<br />
                            if (!imagenames.Contains(relativeimagename))<br />
                            {<br />
                                imagenames.Add(relativeimagename);<br />
                            }<br />
                            position = foundIndexEnd;<br />
                        }<br />
                    }<br />
                }<br />
            }<br />
            return SortNoDuplicate(imagenames);<br />
        }<br />
    }<br />
}<br />
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