www.pudn.com > Windows 2000设备驱动程序设计指南 .zip > Unicode.cpp

// Unicode.cpp 
// 
// Copyright (C) 2000 by Jerry Lozano 
// 
// 
 
#ifdef WIN32DDK_TEST 
#include "DDKTestEnv.h" 
#else 
extern "C" { 
#include  
} 
#endif 
 
#define max(a,b) ((a>b)?a:b) 
 
#include "Unicode.h" 
 
void CUString::Init() { 
	uStr.Length = 0; 
	uStr.MaximumLength = 0; 
	uStr.Buffer = NULL; 
	aType = Empty; 
} 
 
CUString::CUString(const char* pAnsiString) { 
	ANSI_STRING str; 
	RtlInitAnsiString(&str, pAnsiString); 
	uStr.MaximumLength = (USHORT) max(32, RtlAnsiStringToUnicodeSize(&str) ); 
	uStr.Buffer = (PWSTR) 
		ExAllocatePoolWithTag(PagedPool, uStr.MaximumLength, 1633); 
	aType = FromPaged; 
	RtlAnsiStringToUnicodeString(&uStr, &str, FALSE); 
} 
 
CUString::CUString(PCWSTR pWideString) { 
	RtlInitUnicodeString(&uStr, pWideString); 
	aType = FromCode; 
} 
 
CUString::~CUString() { 
	Free(); 
} 
 
void CUString::Free() { 
	if (aType == FromPaged || aType == FromNonPaged) 
		ExFreePool(uStr.Buffer); 
	uStr.Buffer = NULL; 
	uStr.Length = 0; 
	uStr.MaximumLength = 0; 
} 
 
CUString::CUString(const CUString& orig) {	// copy constructor (required) 
	uStr.Length = 0; 
	uStr.MaximumLength = orig.uStr.MaximumLength; 
	uStr.Buffer = (PWSTR) 
		ExAllocatePoolWithTag(PagedPool, uStr.MaximumLength, 1633); 
	aType = FromPaged; 
	RtlCopyUnicodeString(&uStr, (PUNICODE_STRING)&orig.uStr); 
	uStr.Buffer[uStr.Length/2] = UNICODE_NULL; 
} 
 
CUString CUString::operator=(const CUString& rop) {	// assignment operator overload (required) 
	if (&rop != this) {	// lop == rop ??? why was I called 
		if (rop.uStr.Length >= uStr.Length || 	// does it fit? 
			(aType != FromPaged && aType != FromNonPaged) ) { 
			// it doesn't fit - free up existing buffer 
			if (aType == FromPaged || aType == FromNonPaged) 
				ExFreePool(uStr.Buffer); 
			uStr.Length = 0; 
			uStr.MaximumLength = rop.uStr.MaximumLength; 
			// and allocate fresh space 
			uStr.Buffer = (PWSTR) 
				ExAllocatePoolWithTag(PagedPool, uStr.MaximumLength, 1633); 
			aType = FromPaged; 
		} 
		RtlCopyUnicodeString(&uStr, (PUNICODE_STRING)&rop.uStr); 
		uStr.Buffer[uStr.Length/2] = UNICODE_NULL; 
	} 
	return *this; 
} 
BOOLEAN CUString::operator ==(const CUString& rop) const { 
	return RtlEqualUnicodeString(&this->uStr, &rop.uStr, FALSE);	// case matters 
} 
 
CUString::operator PWSTR() const { 
	return uStr.Buffer; 
} 
 
CUString::operator UNICODE_STRING &() { 
	return uStr; 
} 
 
CUString CUString::operator+(const CUString& rop) const { 
	CUString retVal; 
	retVal.uStr.Length = this->uStr.Length + rop.uStr.Length; 
	retVal.uStr.MaximumLength = max(32, retVal.uStr.Length+2); 
	retVal.uStr.Buffer = (PWSTR) 
		ExAllocatePoolWithTag(PagedPool, retVal.uStr.MaximumLength, 1633); 
	RtlCopyUnicodeString(&retVal.uStr, (PUNICODE_STRING)&this->uStr); 
	RtlAppendUnicodeStringToString(&retVal.uStr, (PUNICODE_STRING)&rop.uStr); 
	retVal.uStr.Buffer[retVal.uStr.Length/2] = UNICODE_NULL; 
 
	return retVal; 
} 
 
CUString& CUString::operator+=(const CUString& rop) { 
	*this = *this + rop; 
	return *this; 
} 
 
CUString::operator ULONG() const { 
	ULONG retVal; 
	RtlUnicodeStringToInteger((PUNICODE_STRING)&uStr, 0, &retVal); 
	return retVal; 
} 
 
CUString::CUString(ULONG value) { 
	// Converts from a ULONG into a CUString 
	uStr.Length = 0; 
	uStr.MaximumLength = 32; 
	uStr.Buffer = (PWSTR) 
		ExAllocatePoolWithTag(PagedPool, uStr.MaximumLength, 1633); 
	aType = FromPaged; 
	RtlIntegerToUnicodeString(value, 0, &uStr); 
} 
 
WCHAR& CUString::operator[](int idx) { 
	// accesses an individual WCHAR in CUString buffer 
	if (idx >= 0  && idx < uStr.MaximumLength/2) 
		return uStr.Buffer[idx]; 
	else 
		return uStr.Buffer[0];	// got to return something 
}