Add Attachment base64 image in MailMessage and read it in html body
Completed method to convert a body HTML to an AlternateView
bodyHtml example (you can pass it into the MailMessage code block below)
<p>example</p>
<p><img src=\ "data:image/jpeg;base64,---base64string---"></p>
<p>example</p>
<p><img src=\ "data:image/png;base64,---base64string---"></p>
<p>something</p>
With this method, you can visualize multiple images by many ESPs (gmail, outlook,...)
private static AlternateView ContentToAlternateView(string content)
{
var imgCount = 0;
List<LinkedResource> resourceCollection = new List<LinkedResource>();
foreach (Match m in Regex.Matches(content, "<img(?<value>.*?)>"))
{
imgCount++;
var imgContent = m.Groups["value"].Value;
string type = Regex.Match(imgContent, ":(?<type>.*?);base64,").Groups["type"].Value;
string base64 = Regex.Match(imgContent, "base64,(?<base64>.*?)\"").Groups["base64"].Value;
if (String.IsNullOrEmpty(type) || String.IsNullOrEmpty(base64))
{
//ignore replacement when match normal <img> tag
continue;
}
var replacement = " src=\"cid:" + imgCount + "\"";
content = content.Replace(imgContent, replacement);
var tempResource = new LinkedResource(Base64ToImageStream(base64), new ContentType(type))
{
ContentId = imgCount.ToString()
};
resourceCollection.Add(tempResource);
}
AlternateView alternateView = AlternateView.CreateAlternateViewFromString(content, null, MediaTypeNames.Text.Html);
foreach (var item in resourceCollection)
{
alternateView.LinkedResources.Add(item);
}
return alternateView;
}
Convert Base64 to Stream:
public static Stream Base64ToImageStream(string base64String)
{
byte[] imageBytes = Convert.FromBase64String(base64String);
MemoryStream ms = new MemoryStream(imageBytes, 0, imageBytes.Length);
return ms;
}
Set up MailMessage :
MailMessage mail = new MailMessage();
mail.IsBodyHtml = true;
AlternateView alterView = ContentToAlternateView(bodyHtml);
mail.AlternateViews.Add(alterView);
//more settings
//...
//////////////
SmtpClient smtp = new SmtpClient(Host, Port) { EnableSsl = false };
smtp.Send(mail);
To embed image into your mail message: (Its not same as adding an attachment file to message)
You dont need to convert image to base64 if you are using system.net.mail namespace to send your mail.
var mail = new MailMessage();
var imageToInline = new LinkedResource("Your image full path", MediaTypeNames.Image.Jpeg);
imageToInline.ContentId = "MyImage";
alternateView.LinkedResources.Add(imageToInline);
mail.AlternateViews.Add(body);
Update:
This is somewhat hacky way of embedding image to your mailMessage.
Byte[] bitmapData = Convert.FromBase64String(FixBase64ForImage("Your base64 image string"));
System.IO.MemoryStream streamBitmap = new System.IO.MemoryStream(bitmapData);
public static string FixBase64ForImage(string Image)
{
System.Text.StringBuilder sbText = new System.Text.StringBuilder(Image, Image.Length);
sbText.Replace("\r\n", string.Empty); sbText.Replace(" ", string.Empty);
return sbText.ToString();
}
var mail = new MailMessage();
var imageToInline = new LinkedResource(streamBitmap , MediaTypeNames.Image.Jpeg);
imageToInline.ContentId = "MyImage";
alternateView.LinkedResources.Add(imageToInline);
mail.AlternateViews.Add(body);
And your html mail body should have following tag:
<img alt ="" src ="cid:MyImage"/>
<body>
<img src='data:image/jpeg;base64, <!-- base64 data --> />
</body>
use img tag as above in HTML of mail
or you can attach as below
Attachment attachment = new Attachment(base64String);
attachment.TransferEncoding = TransferEncoding.Base64;
mailmessage.Attachments.Add(attachment);