How to write values from the registry to a .txt file? - c++

I want to read REG_SZ values from the Windows registry and store it in a .txt file.
{
DWORD type = 0;
DWORD index = 0;
std::vector<wchar_t> valueName = std::vector<wchar_t>(maxNameLength+ 1);
//name of value
std::vector<BYTE> dataBuffer = std::vector<BYTE>(maxValueLength);
//Data stored in the value. DataBuffer is LPBYTE value
for (index = 0; index < valueCount; index++) {
DWORD charCountValueName = static_cast<DWORD>(valueName.size());
DWORD charBytesData = static_cast<DWORD>(dataBuffer.size());
status = RegEnumValueW(hKey, index, valueName.data(),&charCountValueName,
NULL, &type, dataBuffer.data(), &charBytesData);
if (type == REG_SZ) { //REG_SZ
const auto reg_string = reinterpret_cast<wchar_t*>(dataBuffer.data());
//Explicit cast of dataBuffer
printf("\nType: REG_SZ\n");
printf("\tName: ");
printf("%ls\n", valueName.data());
printf("\tData : %ls\n", reg_string);
//I want to store this value instead of displaying it
}
}
}
I want to check for the presence/ absence of a few words in the data of the value "Default" of the registry key and thus want too write the data in a .txt file so I can parse it and check for the keywords.

Related

Invalid parameter error using GetDefaultCommConfig

I came up with the same issue,in which I got a LPTSTR portname param as input from a function.I have to convert this into wstring,so that I can fetch the Port paramaters.
below is the code snippet in which am trying to copy lptstr to wstring.
void C_PORT_MONITOR::SetPrinterComPortParam(LPTSTR PortName)
{
#ifdef _UNICODE
std::wstring l_ComPortName;
#else
std::string l_ComPortName;
#endif
DWORD dwSize,le = 0;
dwSize = sizeof(COMMCONFIG);
LPCOMMCONFIG lpCC = (LPCOMMCONFIG) new BYTE[dwSize];
l_ComPortName = PortName;//mPortName;
if(l_ComPortName.length() <= 0 )
return;
bool SetFlag = false;
//Get COMM port params called to get size of config. block
int length = l_ComPortName.length();
int iPos = l_ComPortName.find_first_of(':');
int iChc = length- iPos; //remove the charactrers after :
l_ComPortName = l_ComPortName.substr(0, (length- iChc)); //remove the characters from colon //COM1
//Get COMM port params with defined size
BOOL ret = GetDefaultCommConfig(l_ComPortName.c_str(), lpCC, &dwSize);
_RPT1(_CRT_WARN, "C_PORT_MONITOR::SetPrinterComPortParam length=%x,iPos=%x,iChc=%x,l_ComPortName=%s",length, iPos, iChc, l_ComPortName);
if(!ret)
{
le = GetLastError();
_RPT1(_CRT_WARN ,"C_PORT_MONITOR::SetPrinterComPortParam LastError=%x",le);
}
I need to assign this portname to l_comportname. and I need to create a substring from this l_comportname as COM1 and I have to use this substring in getdafaultcommconfig()
Your error is the second parameter not the first. Your debugging statement is bugged because it doesn't account for wide strings %s is for narrow strings only, you should use %S for a wide string.
Here's the real error
dwSize = sizeof(COMMCONFIG);
LPCOMMCONFIG lpCC = (LPCOMMCONFIG) new BYTE[dwSize];
lpCC->dwSize = sizeof(COMMCONFIG); // this line is needed
You might need this as well (the documentation isn't very clear)
lpCC->wVersion = 1;
It's very common in Windows programming that you have to initialize a struct with the size of the struct.
Ref: https://technet.microsoft.com/en-us/aa363188(v=vs.90)

c++ WINAPI Shared Memory array of structs

I'm trying to share an array of structs through shared named memory using the WINAPI. I'm able to create and manage the shared memory but when trying to share an array of structs the size of the array is always 0 upon reading.
Below is test code i have written which should write/read an array of 10 entries, but even this is failing. My goal is however to write/read a dynamic array of structs containing 2 dynamic arrays and the info they already contain at the moment.
I'm aware i shouldn't share pointers between processes as they could point to a random value. Therefor i'm allocating memory for the arrays using new.
This is what i have so far:
Shared in both processes:
#define MEMSIZE 90024
typedef struct {
int id;
int type;
int count;
} Entry;
Process 1:
extern HANDLE hMapObject;
extern void* vMapData;
std::vector<Entry> entries;//collection of entries
BOOL DumpEntries(TCHAR* memName) {//Returns true, writing 10 entries
int size = min(10, entries.size());
Entry* eArray = new Entry[size];
for (int i = 0; i < size; i++) {
eArray[i] = entries.at(i);
}
::hMapObject = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, MEMSIZE, memName);
if (::hMapObject == NULL) {
return FALSE;
}
::vMapData = MapViewOfFile(::hMapObject, FILE_MAP_ALL_ACCESS, 0, 0, MEMSIZE);
if (::vMapData == NULL) {
CloseHandle(::hMapObject);
return FALSE;
}
CopyMemory(::vMapData, eArray, (size * sizeof(Entry)));
UnmapViewOfFile(::vMapData);
//delete[] eArray;
return TRUE;
}
Process 2:
BOOL ReadEntries(TCHAR* memName, Entry* entries) {//Returns true reading 0 entries
HANDLE hMapFile = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, memName);
if (hMapFile == NULL) {
return FALSE;
}
Entry* tmpEntries = (Entry*)(MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, 10 * sizeof(Entry)));
if (tmpEntries == NULL) {
CloseHandle(hMapFile);
return FALSE;
}
entries = new Entry[10];
for (int i = 0; i < 10; i++) {
entries[i] = tmpEntries[i];
}
UnmapViewOfFile(tmpEntries);
CloseHandle(hMapFile);
return TRUE;
}
Writing the 10 entries seems to be working but when trying to read the memory it returns successfully and the size
of the array is 0, like so:
Entry* entries = NULL;
if (ReadEntries(TEXT("Global\Entries"), entries)) {
int size = _ARRAYSIZE(entries);
out = "Succesfully read: " + to_string(size);// Is always 0
}
So my question is, what am I doing wrong? I'm sharing the same struct between 2 processes, i'm allocating new memory for the entries to be written to and copying the memory with a size of 10 * sizeof(Entry);. When trying to read I also try to read 10 * sizeof(Entry); bytes and cast the data to a Entry*. Is there something I'm missing? All help is welcome.
Based on cursory examination, this code appears to attempt to map structures containing std::strings into shared memory, to be used by another process.
Unfortunately, this adventure is doomed, before it even gets started. Even if you get the array length to pass along correctly, I expect the other process to crash immediately, as soon as it even smells the std::string that the other process attempted to map into shared memory segments.
std::strings are non-trivial classes. A std::string maintains internal pointers to a buffer where the actual string data is kept; with the buffer getting allocated on the heap.
You do understand that sizeof(std::string) doesn't change, whether the string contains five characters, or the entire contents of "War And Peace", right? Stop and think for a moment, how that's possible, in just a few bytes that it takes to store a std::string?
Once you think about it for a moment, it should become crystal clear why mapping one process's std::strings into a shared memory segment, and then attempting to grab them by another process, is not going to work.
The only thing that can be practically mapped to/from shared memory is plain old data; although you could get away with aggregates, in some cases, too.
I'm afraid the problem only lies in the _ARRAYSIZE macro. I could not really find it in MSDN, but I found references for _countof or ARRAYSIZE in other pages. All are defined as sizeof(array)/sizeof(array[0]). The problem is that it only make sense for true arrays defined as Entry entries[10], but not for a pointer to such an array. Technically when you declare:
Entry* entries;
sizeof(entries) is sizeof(Entry *) that is the size of a pointer. It is smaller than the size of the struct so the result of the integer division is... 0!
Anyway, there are other problems in current code. The correct way to exchange a variable size array through shared memory is to use an ancillary structure containing a size and the array itself declared as incomplete:
struct EntryArray {
size_t size;
Entry entries[];
};
You could dump it that way:
BOOL DumpEntries(TCHAR* memName) {//Returns true, writing 10 entries
int size = min(10, entries.size());
EntryArray* eArray = (EntryArray *) malloc(sizeof(EntryArray) + size * sizeof(Entry));
for (int i = 0; i < size; i++) {
eArray->entries[i] = entries.at(i);
}
eArray->size = size;
::hMapObject = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, MEMSIZE, memName);
if (::hMapObject == NULL) {
return FALSE;
}
::vMapData = MapViewOfFile(::hMapObject, FILE_MAP_ALL_ACCESS, 0, 0, MEMSIZE);
if (::vMapData == NULL) {
CloseHandle(::hMapObject);
return FALSE;
}
CopyMemory(::vMapData, eArray, (sizeof(EntryArray) + size * sizeof(Entry)));
UnmapViewOfFile(::vMapData);
free(eArray);
return TRUE;
}
You can note that as the last member of the struct is an incomplete array, it is allocated 0 size, so you must allocate the size of the struct + the size of the array.
You can then read it from memory that way:
size_t ReadEntries(TCHAR* memName, Entry*& entries) {//Returns the number of entries or -1 if error
HANDLE hMapFile = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, memName);
if (hMapFile == NULL) {
return -1;
}
EntryArray* eArray = (EntryArray*)(MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, 10 * sizeof(Entry)));
if (eArray == NULL) {
CloseHandle(hMapFile);
return -1;
}
entries = new Entry[10]; // or even entries = new Entry[eArray->size];
for (int i = 0; i < 10; i++) { // same: i<eArray->size ...
entries[i] = eArray->entries[i];
}
UnmapViewOfFile(eArray);
CloseHandle(hMapFile);
return eArray.size;
}
But here again you should note some differences. As the number of entries is lost when eArray vanishes, it is passed as the return value from the function. And and you want to modify the pointer passed as second parameter, you must pass it by reference (if you pass it by value, you will only change a local copy and still have NULL in original variable after function returns).
There are still some possible improvement in your code, because the vector entries is global when it could be passed as a parameter to DumpEntries, and hMapObject is also global when it could be returned by the function. And in DumpObject you could avoid a copy by building directly the EntryArray in shared memory:
HANDLE DumpEntries(TCHAR* memName, const std::vector<Entry>& entries) {
//Returns HANDLE to mapped file (or NULL), writing 10 entries
int size = min(10, entries.size());
HANDLE hMapObject = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, MEMSIZE, memName);
if (hMapObject == NULL) {
return NULL;
}
void * vMapData = MapViewOfFile(hMapObject, FILE_MAP_ALL_ACCESS, 0, 0, MEMSIZE);
if (vMapData == NULL) {
CloseHandle(hMapObject);
return NULL;
}
EntryArray* eArray = (EntryArray*) vMapData;
for (int i = 0; i < size; i++) {
eArray->entries[i] = entries.at(i);
}
eArray->size = size;
UnmapViewOfFile(vMapData);
return hMapObject;
}
And last but not least, the backslash \ is a special quoting character in a string litteral, and it must quote itself. So you should write .TEXT("Global\\Entries")
I did it some changes to your code:
PROCESS 1:
BOOL DumpEntries(TCHAR* memName)
{
int size = entries.size() * sizeof(Entry) + sizeof(DWORD);
::hMapObject = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, size, memName);
if (::hMapObject == NULL) {
return FALSE;
}
::vMapData = MapViewOfFile(::hMapObject, FILE_MAP_ALL_ACCESS, 0, 0, size);
if (::vMapData == NULL) {
CloseHandle(::hMapObject);
return FALSE;
}
(*(DWORD*)::vMapData) = entries.size();
Entry* eArray = (Entry*)(((DWORD*)::vMapData) + 1);
for(int i = entries.size() - 1; i >= 0; i--) eArray[i] = entries.at(i);
UnmapViewOfFile(::vMapData);
return TRUE;
}
PROCESS 2:
BOOL ReadEntries(TCHAR* memName, Entry** entries, DWORD &number_of_entries) {
HANDLE hMapFile = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, memName);
if (hMapFile == NULL) {
return FALSE;
}
DWORD *num_entries = (DWORD*)MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, 0);
if (num_entries == NULL) {
CloseHandle(hMapFile);
return FALSE;
}
number_of_entries = *num_entries;
if(number_of_entries == 0)
{
// special case: when no entries was found in buffer
*entries = NULL;
return true;
}
Entry* tmpEntries = (Entry*)(num_entries + 1);
*entries = new Entry[*num_entries];
for (UINT i = 0; i < *num_entries; i++) {
(*entries)[i] = tmpEntries[i];
}
UnmapViewOfFile(num_entries);
CloseHandle(hMapFile);
return TRUE;
}
PROCESS 2 (usage example):
void main()
{
Entry* entries;
DWORD number_of_entries;
if(ReadEntries(TEXT("Global\\Entries", &entries, number_of_entries) && number_of_entries > 0)
{
// do something
}
delete entries;
}
CHANGES:
I am not using a static size (MEMSIZE) when i map memory, i am calculating exactly memory requiered
I put a "header" to memory mapped, a DWORD for send to process 2 number of entries in buffer
your ReadEntries definition is wrong, i fix it changing Entry* to Entry**
NOTES:
you need to close ::hMapObject handle in process 1 before process 2 calls ReadEntries
you need to delete entries memory returned for ReadEntries in process 2, before you use it
this code works only under same windows user, if you want to communicate a services with user process (for example), you need to handle SECURITY_ATTRIBUTES member in CreateFileMapping procedure

Reading from a very large text file resource in C++

We have some data in a text file which is built into our executable as a custom resource to be read at runtime. The size of this text file is over 7 million characters.
I can successfully search for and locate strings within the resource which appear near the top of the text file, but when attempting to search for terms a few million characters down, strstr returns NULL indicating that the string cannot be found. Is there a limit to the length of a string literal that can be stored in a char* or the amount of data that can be stored in an embedded resource? Code is shown below
char* data = NULL;
HINSTANCE hInst = NULL;
HRSRC hRes = FindResource(hInst, MAKEINTRESOURCE(IDR_TEXT_FILE1), "TESTRESOURCE");
if(NULL != hRes)
{
HGLOBAL hData = LoadResource(hInst, hRes);
if (hData)
{
DWORD dataSize = SizeofResource(hInst, hRes);
data = (char*)LockResource(hData);
}
else
break;
char* pkcSearchResult = strstr(data, "NumListDetails");
if ( pkcSearchResult != NULL )
{
// parse data
}
}
Thanks.
The problem might be the method you use for searching. strstr uses ANSI strings, and will terminate when it encounters a '\0' in the search domain.
You might use something like memstr (one of many implementations can be found here).
Do you get any output from GetLastError(), specifically after calling SizeofResource.
You can also check that dataSize > 0 to ensure an error hasn't occurred.
DWORD dataSize = SizeofResource(hInst, hRes);
if(dataSize > 0)
{
data = (char*)LockResource(hData);
}
else
{
//check error codes
}
MSDN Docs
The problem was null characters in the data which prematurely ended the char* variable. To get around this I just had to read the data into a void pointer then copy it into a dynamically created array.
DWORD dataSize = SizeofResource(hInst, hRes);
void* pvData = LockResource(hData);
char* pcData = new char[dataSize];
memcpy_s(pcData,strlen(pcData),pvData,dataSize);

How to encrypt and decrypt a const char* in WinRT

I have been trying to write encrypt and decrypt functions whose signatures require the input and the output strings to be void* type only. The code works fine if the inputs can be specified as IBuffer^ but in the other case the source string and the encrypted->decrypted string do not match.
CodeIBuffer^ byteArrayToIBufferPtr(byte *source, int size)
{
Platform::ArrayReference<uint8> blobArray(source, size);
IBuffer ^buffer = CryptographicBuffer::CreateFromByteArray(blobArray);
return buffer;
}
byte* IBufferPtrToByteArray(IBuffer ^buffer)
{
Array<unsigned char,1U> ^platArray = ref new Array<unsigned char,1U>(256);
CryptographicBuffer::CopyToByteArray(buffer,&platArray);
byte *dest = platArray->Data;
return dest;
}
int DataEncryption::encryptData(EncryptionAlgorithm algo, int keySize, void* srcData, const unsigned int srcSize,
void*& encData, unsigned int& encSize)
{
LOG_D(TAG, "encryptData()");
if(srcData == nullptr)
{
LOG_E(TAG,"");
return DataEncryption::RESULT_EMPTY_DATA_ERROR;
}
if(srcSize == 0)
{
LOG_E(TAG,"");
return DataEncryption::RESULT_SIZE_ZERO_ERROR;
}
IBuffer^ encrypted;
IBuffer^ buffer;
IBuffer^ iv = nullptr;
String^ algName;
bool cbc = false;
switch (algo)
{
case DataEncryption::ENC_DEFAULT:
algName = "AES_CBC";
cbc = true;
break;
default:
break;
}
// Open the algorithm provider for the algorithm specified on input.
SymmetricKeyAlgorithmProvider^ Algorithm = SymmetricKeyAlgorithmProvider::OpenAlgorithm(algName);
// Generate a symmetric key.
IBuffer^ keymaterial = CryptographicBuffer::GenerateRandom((keySize + 7) / 8);
CryptographicKey^ key;
try
{
key = Algorithm->CreateSymmetricKey(keymaterial);
}
catch(InvalidArgumentException^ e)
{
LOG_E(TAG,"encryptData(): Could not create key.");
return DataEncryption::RESULT_ERROR;
}
// CBC mode needs Initialization vector, here just random data.
// IV property will be set on "Encrypted".
if (cbc)
iv = CryptographicBuffer::GenerateRandom(Algorithm->BlockLength);
// Set the data to encrypt.
IBuffer ^srcDataBuffer = byteArrayToIBufferPtr(static_cast<byte*>(srcData),256);
// Encrypt and create an authenticated tag.
encrypted = CryptographicEngine::Encrypt(key, srcDataBuffer, iv);
//encData = encrypted;
byte *bb = IBufferPtrToByteArray(encrypted);
encData = IBufferPtrToByteArray(encrypted);
encSize = encrypted->Length;
return DataEncryption::RESULT_SUCCESS;
}
int DataEncryption::decryptData(EncryptionAlgorithm algo, int keySize, void* encData, const unsigned int encSize,
void*& decData, unsigned int& decSize)
{
LOG_D(TAG, "decryptData()");
if(encData == nullptr)
{
LOG_E(TAG,"");
return DataEncryption::RESULT_EMPTY_DATA_ERROR;
}
if(encSize == 0)
{
LOG_E(TAG,"");
return DataEncryption::RESULT_SIZE_ZERO_ERROR;
}
IBuffer^ encrypted;
IBuffer^ decrypted;
IBuffer^ iv = nullptr;
String^ algName;
bool cbc = false;
switch (algo)
{
case DataEncryption::ENC_DEFAULT:
algName = "AES_CBC";
cbc = true;
break;
default:
break;
}
// Open the algorithm provider for the algorithm specified on input.
SymmetricKeyAlgorithmProvider^ Algorithm = SymmetricKeyAlgorithmProvider::OpenAlgorithm(algName);
// Generate a symmetric key.
IBuffer^ keymaterial = CryptographicBuffer::GenerateRandom((keySize + 7) / 8);
CryptographicKey^ key;
try
{
key = Algorithm->CreateSymmetricKey(keymaterial);
}
catch(InvalidArgumentException^ e)
{
LOG_E(TAG,"encryptData(): Could not create key.");
return DataEncryption::RESULT_ERROR;
}
// CBC mode needs Initialization vector, here just random data.
// IV property will be set on "Encrypted".
if (cbc)
iv = CryptographicBuffer::GenerateRandom(Algorithm->BlockLength);
// Set the data to decrypt.
byte *cc = static_cast<byte*>(encData);
IBuffer ^encDataBuffer = byteArrayToIBufferPtr(cc,256);
// Decrypt and verify the authenticated tag.
decrypted = CryptographicEngine::Decrypt(key, encDataBuffer, iv);
byte *bb = IBufferPtrToByteArray(decrypted);
decData = IBufferPtrToByteArray(decrypted);
decSize = decrypted->Length;
return DataEncryption::RESULT_SUCCESS;
}
I'm guessing that the problem is with this function:
byte* IBufferPtrToByteArray(IBuffer ^buffer)
{
Array<unsigned char,1U> ^platArray = ref new Array<unsigned char,1U>(256);
CryptographicBuffer::CopyToByteArray(buffer,&platArray);
byte *dest = platArray->Data;
return dest;
}
What you're doing there is allocating a new Platform::Array<byte>^ with 1 reference, then getting a pointer to its internally-managed storage, then returning that pointer-- at which point the Array is being dereferenced and is thus deallocating its underlying storage. Thus the pointer you return refers to freed memory. The next allocation is likely to overwrite those bytes.
What you'll need to do is take the return-by-reference Array<byte>^ from CopyToByteArray() (which creates a new Array, presumably wrapping the bytes of the input IBuffer^, and returns it) and copy that array's contents.
Your end result will function similarly to this snippet from the Readium SDK project, which takes a std::string instance, hashes it using SHA-1, and copies the hash data into a member variable uint8_t _key[KeySize]:
using namespace ::Platform;
using namespace ::Windows::Foundation::Cryptography;
using namespace ::Windows::Foundation::Cryptography::Core;
auto byteArray = ArrayReference<byte>(reinterpret_cast<byte*>(const_cast<char*>(str.data())), str.length());
auto inBuf = CryptographicBuffer::CreateFromByteArray(byteArray);
auto keyBuf = HashAlgorithmProvider::OpenAlgorithm(HashAlgorithmNames::Sha1)->HashData(inBuf);
Array<byte>^ outArray = nullptr;
CryptographicBuffer::CopyToByteArray(keyBuf, &outArray);
memcpy_s(_key, KeySize, outArray->Data, outArray->Length);
The steps:
Create an ArrayReference<byte> corresponding to the bytes in the std::string (no copying).
Pass that to CryptographicBuffer::CreateFromByteArray() to get your IBuffer^. Still no copying of data.
Call your hash/encryption function, passing the IBuffer^ you just made. You get another IBuffer^ in return, which may or may not be using the exact same storage (that's really up to the implementation of the algorithm, I think).
Create a variable of type Array<byte>^. Don't allocate an object, you're going to be given one by reference.
Pass the address of that object into CryptographicBuffer::CopyToByteArray() to receive a copy of your key data.
While that Array^ remains valid, copy its bytes into your native array.

How do you open a resource string in Visual C++ 2010?

I created a basic stringtable resource in Visual C++. I am trying to access that resource. However, my program can't seem to find the resource. Here:
int main(int argc, char* argv[])
{
HRSRC hRsrc;
hRsrc = FindResource(NULL, MAKEINTRESOURCE(IDS_STRING102), RT_STRING);
if (hRsrc == NULL) {
printf("Not found\n");
} else {
printf("Found\n");
}
}
This program can't find the resource and always returns null.
I created a simple bitmap resource and this new program identifies that just fine. Here:
int main(int argc, char* argv[])
{
HRSRC hRsrc;
hRsrc = FindResource(NULL, MAKEINTRESOURCE(IDB_BITMAP1), RT_BITMAP);
if (hRsrc == NULL) {
printf("Not found\n");
} else {
printf("Found\n");
}
}
This finds the bitmap.
Do stringtable resources get handled somehow differently?
Assuming you do not want to use LoadString() this should help...
Strings and string tables are indeed treated differently when using FindResource() and FindResourceEx(). From this KB article:
String resources are stored as blocks of strings. Each block can have
up to sixteen strings and represents the smallest granularity of
string resource that can be loaded/updated. Each block is identified
by an identifier (ID), starting with one (1). We use this ID when
calling the FindResource, LoadResource and UpdateResource functions.
A string with ID, nStringID, is located in the block with ID,
nBlockID, given by the following formula:
nBlockID = (nStringID / 16) + 1; // Note integer division.
The lower 4 bits of nStringID indicates which entry in the block contains the actual string. Once you have calculated the block ID to pass to FindResource() and the index in the block where the string exists you have to scan through it's contents to find the string you are looking for.
The following code should get you started.
const WCHAR *stringPtr;
WCHAR stringLen;
// Get the id of the string table block containing the target string
const DWORD blockID = (nID >> 4) + 1;
// Get the offset of teh target string in the block
const DWORD itemID = nID % 0x10;
// Find the resource
HRSRC hRes = FindResourceEx(
hInst,
RT_STRING,
MAKEINTRESOURCE(blockID),
wLanguage);
if (hRes)
{
HGLOBAL hBlock = LoadResource(hInst, hRes);
const WCHAR *tableDataBlock = reinterpret_cast<LPCWSTR>(LockResource(hBlock));
const DWORD tableBlockSize = SizeofResource(hInst, hRes);
DWORD searchOffset = 0;
DWORD stringIndex = 0;
// Search through the section for the appropriate entry.
// The first two bytes of each entry is the length of the string
// followed by the Unicode string itself. All strings entries
// are stored one after another with no padding.
while(searchOffset < tableBlockSize)
{
if (stringIndex == itemID)
{
// If the string has size. use it!
if (tableDataBlock[searchOffset] != 0x0000)
{
stringPtr = &tableDataBlock[searchOffset + 1];
stringLen = tableDataBlock[searchOffset];
}
// Nothing there -
else
{
stringPtr = NULL;
stringLen = 0;
}
// Done
break;
}
// Go to the next string in the table
searchOffset += tableDataBlock[searchOffset] + 1;
// Bump the index
stringIndex++;
}
}
You could use LoadString directly instead. Here's some text from the MSDN FindResource documentation...
An application can use FindResource to find any type of resource, but this function should be used only if the application must access the binary resource data by making subsequent calls to LoadResource and then to LockResource.
To use a resource immediately...
...use LoadString!
After 2 days of research I found this(it works!):
#include <atlstr.h>
......
ATL::CString str;
WORD LangID = MAKELANGID(LANG_ENGLISH,SUBLANG_DEFAULT);
str.LoadString(NULL,IDS_STRING101, LangID);