鉴于某些注册表值的关键（例如HKEY_LOCAL_MACHINE \ blah \ blah \ blah \ foo），我该如何：
安全地确定存在这样的密钥 .
以编程方式（即使用代码）获取其值 .
我绝对没有打算将任何东西写回注册表（如果我可以提供帮助的话，我的职业生涯期间） . 因此，如果我错误地写入注册表，我们可以跳过关于我体内每个分子以光速爆炸的讲座 .
首选C中的答案，但大多数情况下只需要知道特殊的Windows API咒语是什么 .
Here is some pseudo-code to retrieve the following:
如果存在注册表项
该注册表项的默认值是什么
字符串值是多少
DWORD值是什么
Example code:
包含库依赖项：Advapi32.lib
HKEY hKey; LONG lRes = RegOpenKeyExW(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Perl", 0, KEY_READ, &hKey); bool bExistsAndSuccess (lRes == ERROR_SUCCESS); bool bDoesNotExistsSpecifically (lRes == ERROR_FILE_NOT_FOUND); std::wstring strValueOfBinDir; std::wstring strKeyDefaultValue; GetStringRegKey(hKey, L"BinDir", strValueOfBinDir, L"bad"); GetStringRegKey(hKey, L"", strKeyDefaultValue, L"bad"); LONG GetDWORDRegKey(HKEY hKey, const std::wstring &strValueName, DWORD &nValue, DWORD nDefaultValue) { nValue = nDefaultValue; DWORD dwBufferSize(sizeof(DWORD)); DWORD nResult(0); LONG nError = ::RegQueryValueExW(hKey, strValueName.c_str(), 0, NULL, reinterpret_cast<LPBYTE>(&nResult), &dwBufferSize); if (ERROR_SUCCESS == nError) { nValue = nResult; } return nError; } LONG GetBoolRegKey(HKEY hKey, const std::wstring &strValueName, bool &bValue, bool bDefaultValue) { DWORD nDefValue((bDefaultValue) ? 1 : 0); DWORD nResult(nDefValue); LONG nError = GetDWORDRegKey(hKey, strValueName.c_str(), nResult, nDefValue); if (ERROR_SUCCESS == nError) { bValue = (nResult != 0) ? true : false; } return nError; } LONG GetStringRegKey(HKEY hKey, const std::wstring &strValueName, std::wstring &strValue, const std::wstring &strDefaultValue) { strValue = strDefaultValue; WCHAR szBuffer[512]; DWORD dwBufferSize = sizeof(szBuffer); ULONG nError; nError = RegQueryValueExW(hKey, strValueName.c_str(), 0, NULL, (LPBYTE)szBuffer, &dwBufferSize); if (ERROR_SUCCESS == nError) { strValue = szBuffer; } return nError; }
const CString REG_SW_GROUP_I_WANT = _T("SOFTWARE\\My Corporation\\My Package\\Group I want"); const CString REG_KEY_I_WANT= _T("Key Name"); CRegKey regKey; DWORD dwValue = 0; if(ERROR_SUCCESS != regKey.Open(HKEY_LOCAL_MACHINE, REG_SW_GROUP_I_WANT)) { m_pobLogger->LogError(_T("CRegKey::Open failed in Method")); regKey.Close(); goto Function_Exit; } if( ERROR_SUCCESS != regKey.QueryValue( dwValue, REG_KEY_I_WANT)) { m_pobLogger->LogError(_T("CRegKey::QueryValue Failed in Method")); regKey.Close(); goto Function_Exit; } // dwValue has the stuff now - use for further processing
该对RegOpenKey和RegQueryKeyEx将成功 .
如果使用MFC CRegKey类则更容易解决 .
RegQueryValueEx
如果该值存在，则给出该值，如果该键不存在，则返回错误代码ERROR_FILE_NOT_FOUND .
（我不知道我的链接是否正常工作，但如果您只是谷歌“RegQueryValueEx”，那么第一个命中就是msdn文档 . ）
由于Windows> = Vista / Server 2008，RegGetValue可用，其中is a safer function比RegQueryValueEx . 无需 RegOpenKeyEx ， RegCloseKey 或 NUL 终止字符串值检查（REG_SZ, REG_MULTI_SZ, REG_EXPAND_SZ） .
RegOpenKeyEx
RegCloseKey
NUL
#include <iostream> #include <string> #include <exception> #include <windows.h> /*! \brief Returns a value from HKLM as string. \exception std::runtime_error Replace with your error handling. */ std::wstring GetStringValueFromHKLM(const std::wstring& regSubKey, const std::wstring& regValue) { size_t bufferSize = 0xFFF; // If too small, will be resized down below. std::wstring valueBuf; // Contiguous buffer since C++11. valueBuf.resize(bufferSize); auto cbData = static_cast<DWORD>(bufferSize); auto rc = RegGetValueW( HKEY_LOCAL_MACHINE, regSubKey.c_str(), regValue.c_str(), RRF_RT_REG_SZ, nullptr, static_cast<void*>(&valueBuf.at(0)), &cbData ); while (rc == ERROR_MORE_DATA) { // Get a buffer that is big enough. cbData /= sizeof(wchar_t); if (cbData > static_cast<DWORD>(bufferSize)) { bufferSize = static_cast<size_t>(cbData); } else { bufferSize *= 2; cbData = static_cast<DWORD>(bufferSize); } valueBuf.resize(bufferSize); rc = RegGetValueW( HKEY_LOCAL_MACHINE, regSubKey.c_str(), regValue.c_str(), RRF_RT_REG_SZ, nullptr, static_cast<void*>(&valueBuf.at(0)), &cbData ); } if (rc == ERROR_SUCCESS) { valueBuf.resize(static_cast<size_t>(cbData / sizeof(wchar_t))); return valueBuf; } else { throw std::runtime_error("Windows system error code: " + std::to_string(rc)); } } int main() { std::wstring regSubKey; #ifdef _WIN64 // Manually switching between 32bit/64bit for the example. Use dwFlags instead. regSubKey = L"SOFTWARE\\WOW6432Node\\Company Name\\Application Name\\"; #else regSubKey = L"SOFTWARE\\Company Name\\Application Name\\"; #endif std::wstring regValue(L"MyValue"); std::wstring valueFromRegistry; try { valueFromRegistry = GetStringValueFromHKLM(regSubKey, regValue); } catch (std::exception& e) { std::cerr << e.what(); } std::wcout << valueFromRegistry; }
其参数 dwFlags 支持类型限制的标志，在失败时使用零填充值缓冲区（ RRF_ZEROONFAILURE ）和64位程序的32/64位注册表访问（ RRF_SUBKEY_WOW6464KEY ， RRF_SUBKEY_WOW6432KEY ） .
dwFlags
RRF_ZEROONFAILURE
RRF_SUBKEY_WOW6464KEY
RRF_SUBKEY_WOW6432KEY
#include <windows.h> #include <map> #include <string> #include <stdio.h> #include <string.h> #include <tr1/stdint.h> using namespace std; void printerr(DWORD dwerror) { LPVOID lpMsgBuf; FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, dwerror, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language (LPTSTR) &lpMsgBuf, 0, NULL ); // Process any inserts in lpMsgBuf. // ... // Display the string. if (isOut) { fprintf(fout, "%s\n", lpMsgBuf); } else { printf("%s\n", lpMsgBuf); } // Free the buffer. LocalFree(lpMsgBuf); } bool regreadSZ(string& hkey, string& subkey, string& value, string& returnvalue, string& regValueType) { char s[128000]; map<string,HKEY> keys; keys["HKEY_CLASSES_ROOT"]=HKEY_CLASSES_ROOT; keys["HKEY_CURRENT_CONFIG"]=HKEY_CURRENT_CONFIG; //DID NOT SURVIVE? keys["HKEY_CURRENT_USER"]=HKEY_CURRENT_USER; keys["HKEY_LOCAL_MACHINE"]=HKEY_LOCAL_MACHINE; keys["HKEY_USERS"]=HKEY_USERS; HKEY mykey; map<string,DWORD> valuetypes; valuetypes["REG_SZ"]=REG_SZ; valuetypes["REG_EXPAND_SZ"]=REG_EXPAND_SZ; valuetypes["REG_MULTI_SZ"]=REG_MULTI_SZ; //probably can't use this. LONG retval=RegOpenKeyEx( keys[hkey], // handle to open key subkey.c_str(), // subkey name 0, // reserved KEY_READ, // security access mask &mykey // handle to open key ); if (ERROR_SUCCESS != retval) {printerr(retval); return false;} DWORD slen=128000; DWORD valuetype = valuetypes[regValueType]; retval=RegQueryValueEx( mykey, // handle to key value.c_str(), // value name NULL, // reserved (LPDWORD) &valuetype, // type buffer (LPBYTE)s, // data buffer (LPDWORD) &slen // size of data buffer ); switch(retval) { case ERROR_SUCCESS: //if (isOut) { // fprintf(fout,"RegQueryValueEx():ERROR_SUCCESS:succeeded.\n"); //} else { // printf("RegQueryValueEx():ERROR_SUCCESS:succeeded.\n"); //} break; case ERROR_MORE_DATA: //what do I do now? data buffer is too small. if (isOut) { fprintf(fout,"RegQueryValueEx():ERROR_MORE_DATA: need bigger buffer.\n"); } else { printf("RegQueryValueEx():ERROR_MORE_DATA: need bigger buffer.\n"); } return false; case ERROR_FILE_NOT_FOUND: if (isOut) { fprintf(fout,"RegQueryValueEx():ERROR_FILE_NOT_FOUND: registry value does not exist.\n"); } else { printf("RegQueryValueEx():ERROR_FILE_NOT_FOUND: registry value does not exist.\n"); } return false; default: if (isOut) { fprintf(fout,"RegQueryValueEx():unknown error type 0x%lx.\n", retval); } else { printf("RegQueryValueEx():unknown error type 0x%lx.\n", retval); } return false; } retval=RegCloseKey(mykey); if (ERROR_SUCCESS != retval) {printerr(retval); return false;} returnvalue = s; return true; }
此控制台应用程序将列出大多数潜在注册表值的注册表项中的所有值及其数据 . 有一些不经常使用的奇怪的 . 如果您需要支持所有这些，请在引用此Registry Value Type文档时从此示例展开 .
这是您可以从 .reg 文件格式导入的注册表项内容：
.reg
Windows Registry Editor Version 5.00 [HKEY_CURRENT_USER\added\subkey] "String_Value"="hello, world!" "Binary_Value"=hex:01,01,01,01 "Dword value"=dword:00001224 "QWord val"=hex(b):24,22,12,00,00,00,00,00 "multi-line val"=hex(7):4c,00,69,00,6e,00,65,00,20,00,30,00,00,00,4c,00,69,00,\ 6e,00,65,00,20,00,31,00,00,00,4c,00,69,00,6e,00,65,00,20,00,32,00,00,00,00,\ 00 "expanded_val"=hex(2):25,00,55,00,53,00,45,00,52,00,50,00,52,00,4f,00,46,00,49,\ 00,4c,00,45,00,25,00,5c,00,6e,00,65,00,77,00,5f,00,73,00,74,00,75,00,66,00,\ 66,00,00,00
控制台应用程序本身：
#include <Windows.h> #include <iostream> #include <string> #include <locale> #include <vector> #include <iomanip> int wmain() { const auto hKey = HKEY_CURRENT_USER; constexpr auto lpSubKey = TEXT("added\\subkey"); auto openedKey = HKEY(); auto status = RegOpenKeyEx(hKey, lpSubKey, 0, KEY_READ, &openedKey); if (status == ERROR_SUCCESS) { auto valueCount = static_cast<DWORD>(0); auto maxNameLength = static_cast<DWORD>(0); auto maxValueLength = static_cast<DWORD>(0); status = RegQueryInfoKey(openedKey, NULL, NULL, NULL, NULL, NULL, NULL, &valueCount, &maxNameLength, &maxValueLength, NULL, NULL); if (status == ERROR_SUCCESS) { DWORD type = 0; DWORD index = 0; std::vector<wchar_t> valueName = std::vector<wchar_t>(maxNameLength + 1); std::vector<BYTE> dataBuffer = std::vector<BYTE>(maxValueLength); for (DWORD index = 0; index < valueCount; index++) { DWORD charCountValueName = static_cast<DWORD>(valueName.size()); DWORD charBytesData = static_cast<DWORD>(dataBuffer.size()); status = RegEnumValue(openedKey, index, valueName.data(), &charCountValueName, NULL, &type, dataBuffer.data(), &charBytesData); if (type == REG_SZ) { const auto reg_string = reinterpret_cast<wchar_t*>(dataBuffer.data()); std::wcout << L"Type: REG_SZ" << std::endl; std::wcout << L"\tName: " << valueName.data() << std::endl; std::wcout << L"\tData : " << reg_string << std::endl; } else if (type == REG_EXPAND_SZ) { const auto casted = reinterpret_cast<wchar_t*>(dataBuffer.data()); TCHAR buffer[32000]; ExpandEnvironmentStrings(casted, buffer, 32000); std::wcout << L"Type: REG_EXPAND_SZ" << std::endl; std::wcout << L"\tName: " << valueName.data() << std::endl; std::wcout << L"\tData: " << buffer << std::endl; } else if (type == REG_MULTI_SZ) { std::vector<std::wstring> lines; const auto str = reinterpret_cast<wchar_t*>(dataBuffer.data()); auto line = str; lines.emplace_back(line); for (auto i = 0; i < charBytesData / sizeof(wchar_t) - 1; i++) { const auto c = str[i]; if (c == 0) { line = str + i + 1; const auto new_line = reinterpret_cast<wchar_t*>(line); if (wcsnlen_s(new_line, 1024) > 0) lines.emplace_back(new_line); } } std::wcout << L"Type: REG_MULTI_SZ" << std::endl; std::wcout << L"\tName: " << valueName.data() << std::endl; std::wcout << L"\tData: " << std::endl; for (size_t i = 0; i < lines.size(); i++) { std::wcout << L"\t\tLine[" << i + 1 << L"]: " << lines[i] << std::endl; } } if (type == REG_DWORD) { const auto dword_value = reinterpret_cast<unsigned long*>(dataBuffer.data()); std::wcout << L"Type: REG_DWORD" << std::endl; std::wcout << L"\tName: " << valueName.data() << std::endl; std::wcout << L"\tData : " << std::to_wstring(*dword_value) << std::endl; } else if (type == REG_QWORD) { const auto qword_value = reinterpret_cast<unsigned long long*>(dataBuffer.data()); std::wcout << L"Type: REG_DWORD" << std::endl; std::wcout << L"\tName: " << valueName.data() << std::endl; std::wcout << L"\tData : " << std::to_wstring(*qword_value) << std::endl; } else if (type == REG_BINARY) { std::vector<uint16_t> bins; for (auto i = 0; i < charBytesData; i++) { bins.push_back(static_cast<uint16_t>(dataBuffer[i])); } std::wcout << L"Type: REG_BINARY" << std::endl; std::wcout << L"\tName: " << valueName.data() << std::endl; std::wcout << L"\tData:"; for (size_t i = 0; i < bins.size(); i++) { std::wcout << L" " << std::uppercase << std::hex << \ std::setw(2) << std::setfill(L'0') << std::to_wstring(bins[i]); } std::wcout << std::endl; } } } } RegCloseKey(openedKey); return 0; }
预期的控制台输出：
Type: REG_SZ Name: String_Value Data : hello, world! Type: REG_BINARY Name: Binary_Value Data: 01 01 01 01 Type: REG_DWORD Name: Dword value Data : 4644 Type: REG_DWORD Name: QWord val Data : 1188388 Type: REG_MULTI_SZ Name: multi-line val Data: Line[1]: Line 0 Line[2]: Line 1 Line[3]: Line 2 Type: REG_EXPAND_SZ Name: expanded_val Data: C:\Users\user name\new_stuff
7 回答
Here is some pseudo-code to retrieve the following:
如果存在注册表项
该注册表项的默认值是什么
字符串值是多少
DWORD值是什么
Example code:
包含库依赖项：Advapi32.lib
该对RegOpenKey和RegQueryKeyEx将成功 .
如果使用MFC CRegKey类则更容易解决 .
RegQueryValueEx
如果该值存在，则给出该值，如果该键不存在，则返回错误代码ERROR_FILE_NOT_FOUND .
（我不知道我的链接是否正常工作，但如果您只是谷歌“RegQueryValueEx”，那么第一个命中就是msdn文档 . ）
由于Windows> = Vista / Server 2008，RegGetValue可用，其中is a safer function比RegQueryValueEx . 无需
RegOpenKeyEx，RegCloseKey或NUL终止字符串值检查（REG_SZ, REG_MULTI_SZ, REG_EXPAND_SZ） .其参数
dwFlags支持类型限制的标志，在失败时使用零填充值缓冲区（RRF_ZEROONFAILURE）和64位程序的32/64位注册表访问（RRF_SUBKEY_WOW6464KEY，RRF_SUBKEY_WOW6432KEY） .此控制台应用程序将列出大多数潜在注册表值的注册表项中的所有值及其数据 . 有一些不经常使用的奇怪的 . 如果您需要支持所有这些，请在引用此Registry Value Type文档时从此示例展开 .
这是您可以从
.reg文件格式导入的注册表项内容：控制台应用程序本身：
预期的控制台输出：