问题
Hello I'm working on a project in .NET 1.1 and I have a requirement to extract (and save it somewhere) embedded image from emails that I'm receiving.
Can someone give me a clue on where to start?
thank you
回答1:
The email downloaded from the POP server will be in text format, you will have to parse the whole email, and find all the <img /> tags having the src attribute set to cid:*
E.g.
<img src='cid:006901c6d391$dee64770$6c822ecf@Z2LC74Q' />
The format of an email containing the embedded image will be as follows -
From: foo1atbar.net
To: foo2atbar.net
Subject: A simple example
Mime-Version: 1.0
Content-Type: multipart/related; boundary="boundary-example"; type="text/html"
--boundary-example
Content-Type: text/html; charset="US-ASCII"
... text of the HTML document, which might contain a URI
referencing a resource in another body part, for example
through a statement such as:
<IMG SRC="cid:foo4atfoo1atbar.net" ALT="IETF logo">
...snip...
Content-Location: CID:somethingatelse ;this header is disregarded
Content-ID: <006901c6d391$dee64770$6c822ecf@Z2LC74Q>
Content-Type: IMAGE/GIF
Content-Transfer-Encoding: BASE64
R0lGODlhGAGgAPEAAP/////ZRaCgoAAAACH+PUNv
cHlyaWdodCAoQykgMTk5LiBVbmF1dGhvcml6ZWQgZHV
wbGljYXRpb24gcHJvaGliaXRlZC4A etc...
...snip...
If you take a look at the footer, it contains a BASE64 encoded version of your image. You can extract the the BASE64 string, convert it to bytes based on the email character set, and save it to a file (you can get the file extension based on the Content-Type). Tada, done!
Hope you've got an idea of how to do it!
EDIT
I also found a similary question here. He's using CDO (Collaboration Data Objects).
来源：https://stackoverflow.com/questions/1259308/net-how-to-extract-embedded-image-from-email-message