Attachment download without basing on BodyPart

[WesolyPierozek]

I noticed one thing which is slightly problematic for me. I have scenario:

• get list of all attachments metadata from email box
• analyse attachments they are necessary or not - basing only of basic mail message data and attachment header data.
• download specified attachments.
  At the moment i used GetBodyPart, but unfortunately it base on BodyPart class. Is it possible to use something another which is better than class to get part of email? Like index, part descriptor etc - and also is easily serializable for further access.

Maybe i'm annoying with creating issues, but is it possible to create "requests"?

[jstedfast]

BodyPart is serializable via the ToString() method and can be deserialized via BodyPart.TryParse (string text, out BodyPart body).

Does that meet your needs?

[WesolyPierozek]

Generally yes, but would be possible to store only something like attachment id/part number?
But for now i will go with approach which you suggested.

I noticed if two different attachments with same name are in message they have same BodyPart.ToString().

Another update:
I'm trying to get specific attachments basing on e-mail massage uid and let's say unique_attachment_id.
I wanted use BodyPart.ToString() for that but i'm failed because it may contains same attachments names with same length. GetBodyPart fails.
I wanted use BodyPart.PartSpecifier but i failed also, it isn't provided in MimePart and MimeEntity. So using GetMessage cannot help.
I wanted use created int index of BodyPart/Attachment but it isn't deterministic. MimeMessage.Attachments is IEnumerable so i won't trust in order.
Attachment FileName is insufficient.

Basically i will ask: is it possible to download specific attachment having email uid and some unique value from IMessageSummary received by Client.Inbox.Fetch(messagesUids, MessageSummaryItems.Full | MessageSummaryItems.BodyStructure); ?

[jstedfast]

I should have probably explained better. You need to ToString() the top-level BodyPart and then, when you are ready to download the specific part, traverse the tree structure again.

The PartSpecifier property is calculated based on the nested level of the BodyPart from the root.

[jstedfast]

The BodyPart.PartSpecifier is the only unique identifier for a specific MIME part that you can use. I didn't want people to have to know the details of the PartSpecifier string because most people calculate it incorrectly, so that is why I was forcing the use of BodyPart objects.

I've added new overrides of GetBodyPart() that take a part specifier string. How you get that is up to you, but I would recommend getting it via the BodyPart object.

[WesolyPierozek]

Yes, I wanted use BodyPart for getting PartSpecifier. Thanks a lot! This is exactly that, what and how i wanted use.

[jstedfast]

excellent :-)