除非我先发送电子邮件，否则C＃不会保存图像

Question

我有很多年的工作代码，但是从2个月开始在Windows 10中出现了错误（在Windows 10中工作了几个月，然后在同一台PC上工作了2个月）。我曾经创建过图像并将其保存在d：\中，然后将其作为附件发送到电子邮件中。从2个月开始，电子邮件停止发送图像文件，我注意到保存在硬盘上的图像，当SmtpServer1.Send(mail1);被激活时，现在我以非常愚蠢的方式解决了问题，我首先向我自己发送空电子邮件，然后保存图像，然后我发送带有附件的所需电子邮件，以及2个月后发生的事情。是windows更新还是安全还是什么？我使用Windows 10在许多PC上测试了该程序并更改了图像位置，但我得到了相同的结果。请一些人帮助我并发送代码以强制保存创建的图像。 我的代码是：

var webBrowser = (WebBrowser)sender;

using( Bitmap bitmap = new Bitmap( 800, webBrowser.Height ) )
{
    webBrowser.DrawToBitmap( bitmap, new Rectangle(0, 0, 800, bitmap.Height ) );
    bitmap.Save( @"d:\wisetemp\wisesoftware.jpg", ImageFormat.Jpeg );
//next 2 lines solved the problem by forcing the file to be saved , thanks to M.Hassan
    var stream = new MemoryStream();
    bitmap.Save(stream, System.Drawing.Imaging.ImageFormat.Jpeg);
}

if( File.Exists( @"d:\wisetemp\wisesoftware.jpg" ) ) 
    mail.Attachments.Add( new Attachment( @"d:\wisetemp\wisesoftware.jpg" ) );

smtpServer.Port = 587;
smtpServer.Credentials = new NetworkCredential( Form1.sender_email, Form1.seder_email_pass );
smtpServer.EnableSsl = true;
smtpServer.Send( mail );

Answer 1

修改您的代码并抛出异常（如果没有发送以跟踪问题的根源

）

  if( File.Exists( @"d:\wisetemp\wisesoftware.jpg" ) ) 
  {
    mail.Attachments.Add( new Attachment( @"d:\wisetemp\wisesoftware.jpg"   ));

   smtpServer.Port = 587;
   smtpServer.Credentials = new NetworkCredential( Form1.sender_email,   Form1.seder_email_pass );
   smtpServer.EnableSsl = true;
 smtpServer.Send( mail );
}
else
{

  //print log information about image size ,location , email send status to help fix problem
   throw Exception ("somethong wrong ...");
 }

修改

我使用了您的代码并完成了缺失的变量，并且它正常工作。 你能试试吗？ 我认为问题可能在于从浏览器创建图像。我设置浏览器高度

   public void Test1(string fromEmailAddress, string password)
    {
        SmtpClient smtpServer = new SmtpClient("smtp.gmail.com");
        WebBrowser webBrowser = new WebBrowser();
        webBrowser.Height = 100;
        var fname = @"wisesoftware.jpg";

        try
        {
            using (Bitmap bitmap = new Bitmap(800, webBrowser.Height))
            {
                webBrowser.DrawToBitmap(bitmap, new Rectangle(0, 0, 800, bitmap.Height));
                bitmap.Save(fname, ImageFormat.Jpeg);
            }
            Attachment attachment = new Attachment(fname, MediaTypeNames.Application.Octet);
            MailMessage mail = new MailMessage();
            mail.From = new MailAddress(fromEmailAddress);
            mail.To.Add(fromEmailAddress);
            mail.Subject = "Test send image";
            mail.Body = "mail with image attachment";

            mail.Attachments.Add(attachment);

            if (File.Exists(fname))
            {
                smtpServer.Port = 587;
                smtpServer.Credentials = new NetworkCredential(fromEmailAddress, password);
                smtpServer.EnableSsl = true;
                smtpServer.Send(mail);
            }
        }
        catch (Exception ex)
        {

            MessageBox.Show(ex.ToString());
        }
    }

编辑2：

将图像作为流发送

  public void Test2(string fromEmailAddress, string password)
    {
        SmtpClient smtpServer = new SmtpClient("smtp.gmail.com");
        WebBrowser webBrowser = new WebBrowser();
        webBrowser.Height = 100;
        var fname = @"wisesoftware.jpg";

        try
        {
            var stream = new MemoryStream();
            using (Bitmap bitmap = new Bitmap(800, webBrowser.Height))
            {
                webBrowser.DrawToBitmap(bitmap, new Rectangle(0, 0, 800, bitmap.Height));
                bitmap.Save(fname, ImageFormat.Jpeg);

                //saving the image to a MemoryStream, and then providing that MemoryStream to the attachment constructor:

                bitmap.Save(stream, ImageFormat.Jpeg);
                stream.Position = 0;

            }
            Attachment attachment = new Attachment(fname, MediaTypeNames.Application.Octet);
            MailMessage mail = new MailMessage();
            mail.From = new MailAddress(fromEmailAddress);
            mail.To.Add(fromEmailAddress);
            mail.Subject = "Test send image";
            mail.Body = "mail with image attachment";
            mail.Attachments.Add(new Attachment(stream, "image/jpg"));
           // mail.Attachments.Add(attachment);

                smtpServer.Port = 587;
                smtpServer.Credentials = new NetworkCredential(fromEmailAddress, password);
                smtpServer.EnableSsl = true;
                smtpServer.Send(mail);

        }
        catch (Exception ex)
        {

            MessageBox.Show(ex.ToString());
        }
    }

编辑3：

//saving image as stream , send email with stream online  and finally save stream to disk
    public void Test3(string fromEmailAddress, string password)
    {
        SmtpClient smtpServer = new SmtpClient("smtp.gmail.com");
        WebBrowser webBrowser = new WebBrowser();
        webBrowser.Height = 100;
        var fname = @"wisesoftware.jpg";

        try
        {
            var stream = new MemoryStream();
            using (Bitmap bitmap = new Bitmap(800, webBrowser.Height))
            {
                webBrowser.DrawToBitmap(bitmap, new Rectangle(0, 0, 800, bitmap.Height));
                //saving the image to a MemoryStream, and then providing that MemoryStream to the attachment constructor:
                bitmap.Save(stream, ImageFormat.Jpeg);
                stream.Position = 0;

            }
            //add stream with defined friendly filename and mediaType as attachment
            Attachment attachment = new Attachment(stream, fname, MediaTypeNames.Image.Jpeg);
            MailMessage mail = new MailMessage();
            mail.From = new MailAddress(fromEmailAddress);
            mail.To.Add(fromEmailAddress);
            mail.Subject = "Test send image";
            mail.Body = "mail with image attachment";
            mail.Attachments.Add(attachment);

            smtpServer.Port = 587;
            smtpServer.Credentials = new NetworkCredential(fromEmailAddress, password);
            smtpServer.EnableSsl = true;
            smtpServer.Send(mail);

            //write stream to file , close stream
            using (FileStream file = new FileStream(fname, FileMode.Create, FileAccess.Write))
            {
                stream.Position = 0;
                stream.WriteTo(file);
                stream.Close();
            }
        }
        catch (Exception ex)
        {

            MessageBox.Show(ex.ToString());
        }
    }