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C#

Create Binary MIME

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Demonstrates how to create and save a multipart/mixed MIME document where the parts (a JPG and a PDF) are NOT base64 encoded, but are instead binary.

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C#
bool success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

Chilkat.Mime mime = new Chilkat.Mime();

mime.SetBodyFromPlainText("This is the plain text body.");
mime.ConvertToMultipartMixed();
mime.AppendPartFromFile("qa_data/jpg/penguins.jpg");
mime.AppendPartFromFile("qa_data/pdf/fishing.pdf");

//  At this point, when saved, the MIME bodies will be base64 encoded.
mime.SaveMime("qa_output/sample.txt");

//  We now have the following MIME where everything is base64 encoded:
//  The code that follows shows how to eliminate the base64 to make this binary MIME.

//  	Content-Type: multipart/mixed; boundary="------------000207060703080505060404"
//  
//  	--------------000207060703080505060404
//  	Content-Type: text/plain
//  	Content-Transfer-Encoding: 7bit
//  
//  	This is the plain text body.
//  	--------------000207060703080505060404
//  	Content-Disposition: attachment; filename="penguins.jpg"
//  	Content-Type: image/jpeg; name="penguins.jpg"
//  	Content-Transfer-Encoding: base64
//  
//  	/9j/4AAQSkZJRgABAgEAYABgAAD/7gAOQWRvYmUAZAAAAAAB/+ESCEV4aWYAAE1NACoAAAAIAAcB
//  	MgACAAAAFAAAAGIBOwACAAAABwAAAHZHRgADAAAAAQAEAABHSQADAAAAAQA/AACcnQABAAAADgAA
//  	...
//  	800a1MlLipJHlyU9en7sqVPkBK+gBj+o+1E91Ld7iJk0pJDO5PmDk4FOGOHy6S3JW120W1uCJ5M0
//  	PBa54edOFAc8ePX/2Q==
//  
//  	--------------000207060703080505060404
//  	Content-Disposition: attachment; filename="fishing.pdf"
//  	Content-Type: application/pdf; name="fishing.pdf"
//  	Content-Transfer-Encoding: base64
//  
//  	JVBERi0xLjMKJcfsj6IKNSAwIG9iago8PC9MZW5ndGggNiAwIFIvRmlsdGVyIC9GbGF0ZURlY29k
//  	ZT4+CnN0cmVhbQp4nM1c288cNxVX09A0myq35tom7bSl8E1hp76P/YpASIiXlEg8tDwVKEJfilIe
//  	...
//  	MDRGMT48OTlENkRFQzExQjkzNjA0Mjc1RUFCNzIyMjI4RjA0RjE+XQo+PgpzdGFydHhyZWYKMjk0
//  	MzY5CiUlRU9GCg==
//  
//  	--------------000207060703080505060404--
//  

//  To make it binary MIME (getting rid of the base64), set the Encoding property to "binary"
//  for the JPG and PDF parts.

Chilkat.Mime jpgPart = new Chilkat.Mime();
mime.PartAt(1,jpgPart);

jpgPart.Encoding = "binary";

Chilkat.Mime pdfPart = new Chilkat.Mime();
mime.PartAt(2,pdfPart);

pdfPart.Encoding = "binary";

//  Now save it.  If you try to view this MIME in a text editor,
//  the JPG and PDF parts will be garbled and unintelligible. That's because
//  the bytes do not represent characters.
mime.SaveMime("qa_output/sampleBinary.mim");

//  The MIME now contains this:

//  	Content-Type: multipart/mixed; boundary="------------000207060703080505060404"
//  
//  	--------------000207060703080505060404
//  	Content-Type: text/plain
//  	Content-Transfer-Encoding: 7bit
//  
//  	This is the plain text body.
//  	--------------000207060703080505060404
//  	Content-Disposition: attachment; filename="penguins.jpg"
//  	Content-Type: image/jpeg; name="penguins.jpg"
//  	Content-Transfer-Encoding: binary
//  
//  	<Binary Data Here>
//  
//  	--------------000207060703080505060404
//  	Content-Disposition: attachment; filename="fishing.pdf"
//  	Content-Type: application/pdf; name="fishing.pdf"
//  	Content-Transfer-Encoding: binary
//  
//  	<Binary Data Here>
//  
//  	--------------000207060703080505060404--
//  

//  Can we load this binary MIME into an Email object?
Chilkat.BinData binData = new Chilkat.BinData();
//  Write the binary MIME into binData;
mime.GetMimeBd(binData);

Chilkat.Email email = new Chilkat.Email();
//  Load the email from the binData.
email.SetFromMimeBd(binData);

//  Note: Many email clients may not be able to correctly process emails
//  using the binary encoding.  Thunderbird has trouble.  Windows Live Mail
//  worked OK.
email.Subject = "Binary MIME Email";
email.From = "admin@chilkatsoft.com";
email.AddTo("Chilkat","support@chilkatsoft.com");
email.SaveEml("qa_output/binaryEmail.eml");

//  Chilkat does not recommend trying to use binary MIME for email.
//  Binary MIME is typically used in HTTP for uploads and downloads.
//  

//  Also, binary MIME is not representable in a string.  
//  If we try to get the MIME as a string, then it must be encoded
//  using base64.

//  Chilkat automatically changes binary encodings to base64
//  when there's an attempt to get the MIME as a string.
Chilkat.StringBuilder sb = new Chilkat.StringBuilder();
email.GetMimeSb(sb);
sb.WriteFile("qa_output/email_fromSb.eml","utf-8",false);

//  Likewise, if we try to get the MIME as a string from the Mime object, 
//  it cannot contain non-character data in a binary encoding.  The binary
//  bytes MUST be in base64.  The act of trying to retrieve the MIME in string
//  format will force Chilkat to convert binary encodings (for non-text parts)
//  to base64.
mime.GetMimeSb(sb);
sb.WriteFile("qa_output/mime_fromSb.eml","utf-8",false);

//  However, the above use of base64 is just for the purpose of making the MIME
//  string friendly.  If we save the MIME to a file, it's still binary:
mime.SaveMime("qa_output/mime_binary.mime");