c# - 在电子邮件中发送内联图像

Question

通过电子邮件发送图像作为正文中的嵌入图像时出现问题。图像文件显示为附件，这没问题，但内联图像部分仅显示为红色 x。

这是我目前的情况

LinkedResource inline = new LinkedResource(filePath);
inline.ContentId = Guid.NewGuid().ToString();
MailMessage mail = new MailMessage();
Attachment att = new Attachment(filePath);
att.ContentDisposition.Inline = true;
mail.From = from_email;
mail.To.Add(data.email);
mail.Subject = "Client: " + data.client_id + " Has Sent You A Screenshot";
mail.Body = String.Format(
    "<h3>Client: " + data.client_id + " Has Sent You A Screenshot</h3>" +
    @"<img src=""cid:{0}"" />", inline.ContentId);

mail.IsBodyHtml = true;
mail.Attachments.Add(att);

Answer 1

一些用于嵌入图像的最小 C# 代码，可以是:

MailMessage mailWithImg = GetMailWithImg();
MySMTPClient.Send(mailWithImg); //* Set up your SMTPClient before!

private MailMessage GetMailWithImg() {
    MailMessage mail = new MailMessage();
    mail.IsBodyHtml = true;
    mail.AlternateViews.Add(GetEmbeddedImage("c:/image.png"));
    mail.From = new MailAddress("yourAddress@yourDomain");
    mail.To.Add("recipient@hisDomain");
    mail.Subject = "yourSubject";
    return mail;
}

private AlternateView GetEmbeddedImage(String filePath) {
    LinkedResource res = new LinkedResource(filePath);
    res.ContentId = Guid.NewGuid().ToString();
    string htmlBody = @"<img src='cid:" + res.ContentId + @"'/>";
    AlternateView alternateView = AlternateView.CreateAlternateViewFromString(htmlBody, null, MediaTypeNames.Text.Html);
    alternateView.LinkedResources.Add(res);
    return alternateView;
}