GdiComment function (wingdi.h)
The GdiComment function copies a comment from a buffer into a specified enhanced-format metafile.
Syntax
BOOL GdiComment(
[in] HDC hdc,
[in] UINT nSize,
[in] const BYTE *lpData
);
Parameters
[in] hdc
A handle to an enhanced-metafile device context.
[in] nSize
The length of the comment buffer, in bytes.
[in] lpData
A pointer to the buffer that contains the comment.
Return value
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero.
Remarks
A comment can include any kind of private information, for example, the source of a picture and the date it was created. A comment should begin with an application signature, followed by the data.
Comments should not contain application-specific or position-specific data. Position-specific data specifies the location of a record, and it should not be included because one metafile may be embedded within another metafile.
A public comment is a comment that begins with the comment signature identifier GDICOMMENT_IDENTIFIER. The following public comments are defined.
| GDICOMMENT_WINDOWS_METAFILE | The GDICOMMENT_WINDOWS_METAFILE public comment contains a Windows-format metafile that is equivalent to an enhanced-format metafile. This comment is written only by the SetWinMetaFileBits function. The comment record, if given, follows the ENHMETAHEADER metafile record. The comment has the following form: |
DWORD ident; // This contains GDICOMMENT_IDENTIFIER.
DWORD iComment; // This contains GDICOMMENT_WINDOWS_METAFILE.
DWORD nVersion; // This contains the version number of the
// Windows-format metafile.
DWORD nChecksum; // This is the additive DWORD checksum for
// the enhanced metafile. The checksum
// for the enhanced metafile data including
// this comment record must be zero.
// Otherwise, the enhanced metafile has been
// modified and the Windows-format
// metafile is no longer valid.
DWORD fFlags; // This must be zero.
DWORD cbWinMetaFile; // This is the size, in bytes. of the
// Windows-format metafile data that follows.
| GDICOMMENT_BEGINGROUP | The GDICOMMENT_BEGINGROUP public comment identifies the beginning of a group of drawing records. It identifies an object within an enhanced metafile. The comment has the following form: |
DWORD ident; // This contains GDICOMMENT_IDENTIFIER.
DWORD iComment; // This contains GDICOMMENT_BEGINGROUP.
RECTL rclOutput; // This is the bounding rectangle for the
// object in logical coordinates.
DWORD nDescription; // This is the number of characters in the
// optional Unicode description string that
// follows. This is zero if there is no
// description string.
| GDICOMMENT_ENDGROUP | The GDICOMMENT_ENDGROUP public comment identifies the end of a group of drawing records. The GDICOMMENT_BEGINGROUP comment and the GDICOMMENT_ENDGROUP comment must be included in a pair and may be nested. The comment has the following form: |
DWORD ident; // This contains GDICOMMENT_IDENTIFIER.
DWORD iComment; // This contains GDICOMMENT_ENDGROUP.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | wingdi.h (include Windows.h) |
| Library | Gdi32.lib |
| DLL | Gdi32.dll |