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| LONG WINAPI MimeDecodeText( |
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UINT nEncodingType, |
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LPCTSTR lpszInput, |
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LONG cchInput, |
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LPTSTR lpszOutput, |
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LONG cchOutput |
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The MimeDecodeText function decodes a string which was
previously encoded using base64 or quoted-printable encoding.
Parameters
- nEncodingType
- An integer value that specifies the encoding method used. It may
be zero or one of the following values:
| Constant |
Description |
| MIME_ENCODING_QUOTED |
Quoted-printable encoding is designed for textual messages
where most of the characters are represented by the ASCII
character set and is generally human-readable. Non-printable
characters or 8-bit characters with the high bit set are
encoded as hexadecimal values and represented as 7-bit text.
Quoted-printable encoding is typically used for messages which
use character sets such as ISO-8859-1, as well as those which
use HTML. |
| MIME_ENCODING_BASE64 |
Base64 encoding converts binary or text data to ASCII by
translating it so each base64 digit represents 6 bits of data.
This encoding method is commonly used with messages that contain
binary data (such as binary file attachments), or when text uses
extended characters that cannot be represented by 7-bit ASCII.
It is recommended that you use base64 encoding with Unicode
text. This is the default encoding type used by this function. |
- lpszInput
- A pointer to a null terminated string which contains the encoded
text. This parameter cannot be a NULL pointer.
- cchInput
- An integer value which specifies the number of characters of
text in the input string which should be decoded. If this value is
-1, the entire length of the string up to the terminating null will
be decoded.
- lpszOutput
- A pointer to a string buffer that will contain the decoded text.
This buffer must be large enough to store all of the characters in
the decoded text, including the terminating null character. This
parameter cannot be NULL.
- cchOutput
- An integer value which specifies the maximum number of
characters which can be copied into the output string buffer. The
buffer must be large enough to store all of the decoded text and
terminating null character. This value must be greater than zero.
Return Value
If the input buffer can be successfully decoded, the return value is the
length of the decoded output string. If the function returns zero,
then no text was decoded and the output string buffer will be empty.
If the function fails, the return value is MIME_ERROR. To get
extended error information, call MimeGetLastError.
Remarks
This function provides a means to decode text that was previously
encoded using either base64 or quoted-printable encoding. In most
cases, it is not necessary to use this function because the message
parser will automatically decode the message text if necessary.
This function and the MimeEncodeText function use
the UTF-8 character set. If the Unicode version of this function is
called, the output text will be decoded as UTF-8, then converted to
UTF-16 and returned to the caller. If the ANSI version of this
function is used, the decoded output will always be returned to the
caller using the UTF-8 character set.
If an unsupported encoding type is specified, this function will
return MIME_ERROR and the output text string will be empty. In most
cases, it is preferable to use MIME_ENCODING_BASE64 as the encoding
method, with quoted-printable encoding only used for legacy support.
If the original text was encoded using a different character set,
use the MimeDecodeTextEx function, which enables you to
specify an alternate character set.
Requirements
Minimum Desktop Platform: Windows 7 (Service Pack 1)
Minimum Server Platform: Windows Server 2008 R2 (Service Pack 1)
Header File: cstools10.h
Import Library: csmsgv10.lib
Unicode: Implemented as Unicode and ANSI versions.
See Also
MimeDecodeTextEx,
MimeEncodeText,
MimeEncodeTextEx,
MimeGetMessageText,
MimeLocalizeText,
MimeSetMessageText
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