(Delphi DLL) MIME -- Convert Base64 to Binary

Loads MIME containing a base64 body and converts it to binary. This changes the Content-Transfer-Encoding header to "binary", and the body is stored as raw unencoded bytes.

The MIME file initially loaded in this example contains:

Content-Disposition: attachment; filename="starfish20.jpg"
Content-Type: image/jpeg; name="starfish20.jpg"
Content-Transfer-Encoding: base64
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==

After converting, the binary MIME looks like the following. (Note: Loading it into a text editor and saving it will corrupt the binary data by dropping bytes. Non-text binary data CANNOT be handled as if it were text without corruption.)

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Mime, FileAccess, CkByteData;

...

procedure TForm1.Button1Click(Sender: TObject);
var
mime: HCkMime;
success: Boolean;
mimeStr: PWideChar;
mimeBytes: HCkByteData;
fac: HCkFileAccess;

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

mime := CkMime_Create();

success := CkMime_LoadMimeFile(mime,'qa_data/mime/starfish20_base64.mim');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkMime__lastErrorText(mime));
    Exit;
  end;

// Show the MIME.  We can see the body is base64 encoded.
mimeStr := CkMime__getMime(mime);
Memo1.Lines.Add(mimeStr);

// Change the Content-Transfer-Encoding to "binary"
CkMime_SetHeaderField(mime,'Content-Transfer-Encoding','binary');

// Note: Now that the MIME's body is binary (JPG image data),
// we CANNOT get the MIME as a string.  We can only get it as bytes.

mimeBytes := CkByteData_Create();
success := CkMime_GetMimeBytes(mime,mimeBytes);

// We can save it to a file, and then examine it..
fac := CkFileAccess_Create();
success := CkFileAccess_WriteEntireFile(fac,'qa_data/mime/starfish20_binary.mim',mimeBytes);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkFileAccess__lastErrorText(fac));
  end
else
  begin
    Memo1.Lines.Add('Saved binary MIME.');
  end;

CkMime_Dispose(mime);
CkByteData_Dispose(mimeBytes);
CkFileAccess_Dispose(fac);

end;