GlobalAddAtomW function (winbase.h)

Adds a character string to the global atom table and returns a unique value (an atom) identifying the string.

Syntax

ATOM GlobalAddAtomW(
  [in] LPCWSTR lpString
);

Parameters

[in] lpString

Type: LPCTSTR

The null-terminated string to be added. The string can have a maximum size of 255 bytes. Strings that differ only in case are considered identical. The case of the first string of this name added to the table is preserved and returned by the GlobalGetAtomName function.

Alternatively, you can use an integer atom that has been converted using the MAKEINTATOM macro. See the Remarks for more information.

Return value

Type: ATOM

If the function succeeds, the return value is the newly created atom.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If the string already exists in the global atom table, the atom for the existing string is returned and the atom's reference count is incremented.

The string associated with the atom is not deleted from memory until its reference count is zero. For more information, see the GlobalDeleteAtom function.

Global atoms are not deleted automatically when the application terminates. For every call to the GlobalAddAtom function, there must be a corresponding call to the GlobalDeleteAtom function.

If the lpString parameter has the form "#1234", GlobalAddAtom returns an integer atom whose value is the 16-bit representation of the decimal number specified in the string (0x04D2, in this example). If the decimal value specified is 0x0000 or is greater than or equal to 0xC000, the return value is zero, indicating an error. If lpString was created by the MAKEINTATOM macro, the low-order word must be in the range 0x0001 through 0xBFFF. If the low-order word is not in this range, the function fails.

If lpString has any other form, GlobalAddAtom returns a string atom.

Note

The winbase.h header defines GlobalAddAtom as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

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 winbase.h (include Windows.h)
Library Kernel32.lib
DLL Kernel32.dll

See also

AddAtom

DeleteAtom

FindAtom

GetAtomName

GlobalDeleteAtom

GlobalFindAtom

GlobalGetAtomName

MAKEINTATOM

Reference