Delphi Indy10 IMAP 解码 MIME 附件

Question

使用德尔福11。

使用

TIdIMAP4

下载电子邮件后，扫描

MessageParts

，如何检测

MessagePart

是否包含 MIME 编码附件，以及如何将其解码为原始格式（图像、文档等）？

procedure TImapForm.ProcessEmail(MSG: TIdMessage); 
begin
  ContainsAttachement := false;
    
  if Msg.MessageParts.Count > 0 then
  begin
    for i := 0 to Pred(Msg.MessageParts.Count) do
    begin
      if Msg.MessageParts.Items[i] is TIdText then
      begin
        // Process Text-only message here (Don't want HTML)
      end else
      begin
        ContainsAttachement := true;

        // if Msg.MessageParts[i].MessageParts.Encoding = meMIME then
        if MSG.ContentTransferEncoding = 'base64' then //??
        if Msg.MessageParts.Items[i].IsEncoded then //??
        begin
          // How to actually decode the MessagePart to a binary file?
        end;

      end;
    end;
  end;
end;

电子邮件示例：

This is a multi-part message in MIME format.
--------------wt6iyRLyQwO4w89MYm2jGb0w
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

test

--------------wt6iyRLyQwO4w89MYm2jGb0w
Content-Type: image/jpeg; name="Bart.jpg"
Content-Disposition: attachment; filename="Bart.jpg"
Content-Transfer-Encoding: base64

/9j/4AAQSkZJRgABAQEASABIAAD/4ThFRXhpZgAASUkqAAgAAAAMAA4BAgAgAAAAngAAAA8B
AgAUAAAAvgAAABABAgAHAAAA1gAAABIBAwABAAAAAQAAABoBBQABAAAA7gAAABsBBQABAAAA
9gAAACgBAwABAAAAAgAAADEBAgAIAAAA/gAAADIBAgAUAAAAHgEAABMCAwABAAAAAgAAAGmH
etc.

Answer 1

TIdMessage

已经为你处理好了。寻找

TIdAttachmeent

而不是

TIdText

，例如：

procedure TImapForm.ProcessEmail(MSG: TIdMessage); 
begin
  ContainsAttachement := false;
    
  for i := 0 to Pred(Msg.MessageParts.Count) do
  begin
    if Msg.MessageParts.Items[i] is TIdText then
    begin
      // Process Text-only message here (Don't want HTML)
    end
    else if Msg.MessageParts.Items[i] is TIdAttachment then
    begin
      ContainsAttachement := true;
      TIdAttachment(Msg.MessageParts.Items[i]).SaveToFile(...);
    end;
  end;
end;