AddAtom

AddAtom

The AddAtom function adds a character string to the local atom table and returns a unique value (an atom) identifying the string.

ATOM AddAtom(

LPCTSTR lpString	// pointer to string to add
);

Parameters

lpString

Pointer to the null-terminated string to be added. The string can have a maximum size of 255 bytes. Strings differing only in case are considered identical. The case of the first string added is preserved and returned by the GetAtomName function.

Return Values

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

The AddAtom function stores no more than one copy of a given string in the atom table. If the string is already in the table, the function returns the existing atom and, in the case of a string atom, increments the string's reference count.

The MAKEINTATOM macro can be used to convert a WORD value into a string that can be added to the atom table by using the AddAtom function.

AddAtom returns a string atom whose value is in the range 0xC000 through 0xFFFF.

If lpString has the form "#1234", AddAtom 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 a value in the range 0xC000 through 0xFFFF, the return value is zero, indicating an error. If lpString is in the range 0x0001 through 0xBFFF, the return value is the low-order word of lpString.