RtlMultiByteToUnicodeSize function (ntifs.h)
The RtlMultiByteToUnicodeSize routine determines the number of bytes that are required to store the Unicode translation for the specified source string. The translation is assumed to use the current system ANSI code page (ACP). The source string is not necessarily from a multibyte character set.
Syntax
NTSYSAPI NTSTATUS RtlMultiByteToUnicodeSize(
[out] PULONG BytesInUnicodeString,
[in] const CHAR *MultiByteString,
[in] ULONG BytesInMultiByteString
);
Parameters
[out] BytesInUnicodeString
Pointer to a caller-allocated variable that receives the number of bytes that are required to store the translated string.
[in] MultiByteString
Pointer to the source string for which the Unicode length is to be calculated.
[in] BytesInMultiByteString
Length, in bytes, of the source string.
Return value
RtlMultiByteToUnicodeSize returns STATUS_SUCCESS.
Remarks
RtlMultiByteToUnicodeSize can be called to determine how much memory to allocate, or possibly, the value to specify for MaxBytesInUnicodeString, before translating a multibyte string into Unicode with RtlMultiByteToUnicodeN. The returned value does not include space for a NULL terminator for the Unicode string.
Like RtlMultiByteToUnicodeN, RtlMultiByteToUnicodeSize supports only precomposed Unicode characters that are mapped to the current system ANSI code page installed at system boot.
For information about other string-handling routines, see Run-Time Library (RTL) Routines.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Universal |
| Header | ntifs.h (include Ntifs.h) |
| Library | NtosKrnl.lib |
| DLL | NtosKrnl.exe |
| IRQL | < DISPATCH_LEVEL |