iTextSharp - 在电子邮件附件中发送内存中的 pdf

Question

我在这里问了几个问题，但仍有问题。如果您能告诉我我在代码中做错了什么，我将不胜感激。我从 ASP.Net 页面运行上面的代码并得到“无法访问封闭的流”。

var doc = new Document();

MemoryStream memoryStream = new MemoryStream();

PdfWriter.GetInstance(doc, memoryStream);
doc.Open();
doc.Add(new Paragraph("First Paragraph"));
doc.Add(new Paragraph("Second Paragraph"));

doc.Close(); //if I remove this line the email attachment is sent but with 0 bytes 

MailMessage mm = new MailMessage("username@gmail.com", "username@gmail.com")
{
    Subject = "subject",
    IsBodyHtml = true,
    Body = "body"
};

mm.Attachments.Add(new Attachment(memoryStream, "test.pdf"));
SmtpClient smtp = new SmtpClient
{
    Host = "smtp.gmail.com",
    Port = 587,
    EnableSsl = true,
    Credentials = new NetworkCredential("username@gmail.com", "my_password")
};

smtp.Send(mm); //the "Cannot Access a Closed Stream" error is thrown here

谢谢！！！

编辑：

只是为了帮助寻找这个问题的答案的人，无需实际创建文件即可发送附加到电子邮件的 pdf 文件的代码如下（感谢 Ichiban 和 Brianng）：

var doc = new Document();
MemoryStream memoryStream = new MemoryStream();
PdfWriter writer = PdfWriter.GetInstance(doc, memoryStream);

doc.Open();
doc.Add(new Paragraph("First Paragraph"));
doc.Add(new Paragraph("Second Paragraph"));

writer.CloseStream = false;
doc.Close();
memoryStream.Position = 0;

MailMessage mm = new MailMessage("username@gmail.com", "username@gmail.com")
{
    Subject = "subject",
    IsBodyHtml = true,
    Body = "body"
};

mm.Attachments.Add(new Attachment(memoryStream, "filename.pdf"));
SmtpClient smtp = new SmtpClient
{
    Host = "smtp.gmail.com",
    Port = 587,
    EnableSsl = true,
    Credentials = new NetworkCredential("username@gmail.com", "password")

};

smtp.Send(mm);

Answer 1

我遇到了同样的问题，我用这个帖子解决了。在brianng写的代码中

PdfWriter writer = PdfWriter.GetInstance(doc, memoryStream);

// Build pdf code...

writer.CloseStream = false;
doc.Close();

// Build email

memoryStream.Position = 0;
mm.Attachments.Add(new Attachment(memoryStream, "test.pdf"));

我认为而不是写作

writer.CloseStream = false and memoryStream.Position = 0;

只需创建一个新流

MemoryStream m = new MemoryStream(memoryStream);

然后调用

mm.Attachments.Add(new Attachment(memoryStream, "test.pdf"));

两者都有效，但我认为创建新流更好

Answer 2

我尝试了brianng 发布的代码，它成功了。只需将代码的顶部更改为：

var doc = new Document();
MemoryStream memoryStream = new MemoryStream();
PdfWriter writer = PdfWriter.GetInstance(doc, memoryStream); //capture the object
doc.Open();
doc.Add(new Paragraph("First Paragraph"));
doc.Add(new Paragraph("Second Paragraph"));
writer.CloseStream = false; //set the closestream property
doc.close(); //close the document without closing the underlying stream
memoryStream.Position = 0;

/* remainder of your code stays the same*/

Answer 3

你试过了吗：

PdfWriter writer = PdfWriter.GetInstance(doc, memoryStream);

// Build pdf code...

writer.CloseStream = false;
doc.Close();

// Build email

memoryStream.Position = 0;
mm.Attachments.Add(new Attachment(memoryStream, "test.pdf"));

如果我没记错的话，这解决了之前项目中的类似问题。

见http://forums.asp.net/t/1093198.aspx

Answer 4

可能调用 doc.Close() 处理底层流。尝试删除 doc.Close() 而不是该行 set memoryStream.Position = 0;

您也可以使用临时文件：

var tempFilePath = Path.GetTempFileName();

try 
{           
    var doc = new Document();

    PdfWriter.GetInstance(doc, File.OpenWrite(tempFilePath));
    doc.Open();
    doc.Add(new Paragraph("First Paragraph"));
    doc.Add(new Paragraph("Second Paragraph"));

    doc.Close();

    MailMessage mm = new MailMessage("username@gmail.com", "username@gmail.com")
    {
        Subject = "subject",
        IsBodyHtml = true,
        Body = "body"
    };

    mm.Attachments.Add(new Attachment(tempFilePath, "test.pdf"));
    SmtpClient smtp = new SmtpClient
    {
        Host = "smtp.gmail.com",
        Port = 587,
        EnableSsl = true,
        Credentials = new NetworkCredential("username@gmail.com", "my_password")
    };

    smtp.Send(mm);
}
finally
{
    File.Delete(tempFilePath);
}

Answer 5

您能否刷新文档或内存流，然后在附加后将其关闭？