dwFlags A set of bit flags that indicate whether to translate to precomposed or composite wide characters (if a composite form exists), whether to use glyph characters in place of control characters, and how to deal with invalid characters. You can specify a combination of the following flag constants: Value Meaning MB_PRECOMPOSED Always use precomposed characters — that is, characters in which a base character and a nonspacing character have a single character value. This is the default translation option. Cannot be used with MB_COMPOSITE. MB_COMPOSITE Always use composite characters — that is, characters in which a base character and a nonspacing character have different character values. Cannot be used with MB_PRECOMPOSED. MB_ERR_INVALID_CHARS If the function encounters an invalid input character, it fails and GetLastError returns ERROR_NO_UNICODE_TRANSLATION. MB_USEGLYPHCHARS Use glyph characters instead of control characters.
A composite character consists of a base character and a nonspacing character, each having different character values. A precomposed character has a single character value for a base/non-spacing character combination. In the character è, the e is the base character and the accent grave mark is the nonspacing character.
The function's default behavior is to translate to the precomposed form. If a precomposed form does not exist, the function attempts to translate to a composite form.
The flags MB_PRECOMPOSED and MB_COMPOSITE are mutually exclusive. The MB_USEGLYPHCHARS flag and the MB_ERR_INVALID_CHARS can be set regardless of the state of the other flags.
