| LONG WINAPI DecodeBuffer( |
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LPCTSTR lpszInput, |
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LPBYTE lpOutput, |
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LONG cbOutput, |
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DWORD dwOptions |
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The DecodeBuffer function decodes an encoded string, and
stores the result in the specified buffer.
Parameters
- lpszInput
- A pointer to a string which contains the base64
encoded text.
- lpOutput
- A pointer to a byte array buffer which is used to store the
decoded data. It is recommended that the buffer be as large as the
length of the encoded string.
- cbOutput
- A long integer which specifies the maximum number of bytes
which may be stored in the buffer.
- dwOptions
- An unsigned integer that specifies one or more options. This
parameter is constructed by using a bitwise operator with any of
the following values:
| Value |
Description |
| DATA_DECODE_BASE64 |
Decode a string that was created using the base64 encoding
algorithm. This is the encoding method that is used by most
modern email client software. Note that this option cannot be
combined with other decoding methods. |
| DATA_DECODE_QUOTED |
Decode a string that was created using the quoted-printable
encoding algorithm. Note that this option cannot be combined
with the other decoding methods. |
| DATA_DECODE_URL |
Decode a string that was created using the URL encoding
algorithm. Note that this option cannot be combined with the
other decoding methods. |
| DATA_DECODE_UTF7 |
Decode a string that was created using the UTF-7 encoding
algorithm. Note that this option cannot be combined with the
other decoding methods. |
| DATA_DECODE_UTF8 |
Decode a string that was created using the UTF-8 encoding
algorithm. Note that this option cannot be combined with the
other decoding methods. |
| DATA_DECODE_COMPRESSED |
The data was compressed prior to being encoded, and should
be expanded after the decoding has completed successfully. This
option is ignored if the encoding type is not base64. This
should only be used if it was specified when the data was
encoded. |
Return Value
If the function succeeds, it will return the number of bytes
decoded and stored in the buffer. If the function fails, it will
return -1. Failure typically indicates that the encoded string was
corrupted or the buffer is not large enough to store the decoded
data.
Remarks
The DecodeBuffer function is used to decode a block of data
that was previously encoded with the EncodeBuffer function. To
decode the contents of a file, it is recommended that you use the
DecodeFile function instead.
If you specify either UTF-7 or UTF-8 encoding, the lpOutput
parameter must point to a Unicode string and the cbOutput
parameter must specify the maximum number of characters, not bytes,
that can be copied into the string. The return value will be the
number of Unicode characters, not bytes, that were copied into the
output buffer. The conversion is always performed using the default
system code page.
It is recommended that you use the UnicodeEncodeText
function to convert a string to UTF-8 encoded text, and the
UnicodeDecodeText function to convert UTF-8 encoded text to a
UTF-16 or localized multi-byte string.
Requirements
Minimum Desktop Platform: Windows 7 Service Pack 1
Minimum Server Platform: Windows Server 2008 R2 Service Pack 1
Header File: cstools11.h
Import Library: csncdv11.lib
Unicode: Implemented as Unicode and ANSI versions
See Also
DecodeFile,
EncodeBuffer,
EncodeFile,
GetMessageDigest,
IsUnicodeText,
UnicodeDecodeText,
UnicodeEncodeText
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