String Conversion Macros
The latest version of this topic can be found at String Conversion Macros.
These macros provide string conversion features.
ATL and MFC String Conversion Macros | Set of macros that convert between string types. |
DEVMODE and TEXTMETRIC String Conversion Macros | Set of macros that convert the strings within DEVMODE and TEXTMETRIC structures. |
The string conversion macros discussed here are valid for both ATL and MFC. For more information on MFC string conversion, see TN059: Using MFC MBCS/Unicode Conversion Macros and MFC Macros and Globals.
ATL 7.0 String Conversion Classes and Macros
ATL 3.0 String Conversion Macros
These macros create a copy of a DEVMODE or TEXTMETRIC structure and convert the strings within the new structure to a new string type. The macros allocate memory on the stack for the new structure and return a pointer to the new structure.
MACRONAME(Â
address_of_structure Â)
For example:
DEVMODEW* lpw = DEVMODEA2W(lpa);
and:
TEXTMETRICW* lptmw = TEXTMETRICA2W(lptma);
In the macro names, the string type in the source structure is on the left (for example, A) and the string type in the destination structure is on the right (for example, W). A stands for LPSTR, OLE stands for LPOLESTR
, T stands for LPTSTR
, and W stands for LPWSTR
.
Thus, DEVMODEA2W
copies a DEVMODE
structure with LPSTR strings into a DEVMODE
structure with LPWSTR
strings, TEXTMETRICOLE2T
copies a TEXTMETRIC
structure with LPOLESTR
strings into a TEXTMETRIC
structure with LPTSTR
strings, and so on.
The two strings converted in the DEVMODE
structure are the device name ( dmDeviceName) and the form name ( dmFormName). The DEVMODE
string conversion macros also update the structure size ( dmSize).
The four strings converted in the TEXTMETRIC
structure are the first character ( tmFirstChar), the last character ( tmLastChar), the default character ( tmDefaultChar), and the break character ( tmBreakChar).
The behavior of the DEVMODE
and TEXTMETRIC
string conversion macros depends on the compiler directive in effect, if any. If the source and destination types are the same, no conversion takes place. Compiler directives change T and OLE as follows:
Compiler directive in effect | T becomes | OLE becomes |
---|---|---|
none | A | W |
_UNICODE | W | W |
OLE2ANSI | A | A |
_UNICODE and OLE2ANSI | W | A |
The following table lists the DEVMODE
and TEXTMETRIC
string conversion macros.
DEVMODEA2W |
TEXTMETRICA2W |
DEVMODEOLE2T |
TEXTMETRICOLE2T |
DEVMODET2OLE |
TEXTMETRICT2OLE |
DEVMODEW2A |
TEXTMETRICW2A |