Frage

Angesichts des Schlüssels für einen Registrierungswert (z. B.HKEY_LOCAL_MACHINE\blah\blah\blah\foo) wie kann ich:

  1. Stellen Sie sicher fest, dass ein solcher Schlüssel vorhanden ist.
  2. Programmatisch (d. h.mit Code) seinen Wert erhalten.

Ich habe absolut nicht die Absicht, irgendetwas in das Register zurückzuschreiben (für die Dauer meiner Karriere, wenn ich es vermeiden kann).Daher können wir den Vortrag darüber, dass jedes Molekül in meinem Körper mit Lichtgeschwindigkeit explodiert, überspringen, wenn ich falsch in das Register schreibe.

Bevorzugen Sie Antworten in C++, müssen aber meist nur wissen, wie die spezielle Windows-API-Beschwörung lautet, um den Wert zu ermitteln.

War es hilfreich?

Lösung

Hier ist ein Pseudocode, um Folgendes abzurufen:

  1. Wenn ein Registrierungsschlüssel vorhanden ist
  2. Was ist der Standardwert für diesen Registrierungsschlüssel?
  3. Was für ein Stringwert ist
  4. Was für ein DWORD-Wert ist

Beispielcode:

Schließen Sie die Bibliotheksabhängigkeit ein: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;
}

Andere Tipps

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

Das Paar RegOpenKey Und RegQueryKeyEx wird den Zweck erfüllen.

Wenn Sie MFC verwenden CRegKey Klasse ist eine noch einfachere Lösung.

RegQueryValueEx

Dies gibt den Wert an, wenn er existiert, und gibt einen Fehlercode ERROR_FILE_NOT_FOUND zurück, wenn der Schlüssel nicht existiert.

(Ich kann nicht sagen, ob mein Link funktioniert oder nicht, aber wenn Sie einfach nach „RegQueryValueEx“ googeln, ist der erste Treffer die MSDN-Dokumentation.)

Seit Windows >=Vista/Server 2008, RegGetValue vorhanden ist, welches ist eine sicherere Funktion als RegQueryValueEx.Kein Bedarf für RegOpenKeyEx, RegCloseKey oder NUL Beendigungsprüfungen von String-Werten (REG_SZ, REG_MULTI_SZ, REG_EXPAND_SZ).

#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;
}

Sein Parameter dwFlags unterstützt Flags für die Typbeschränkung und füllt den Wertpuffer bei Fehler mit Nullen (RRF_ZEROONFAILURE) und 32/64-Bit-Registrierungszugriff (RRF_SUBKEY_WOW6464KEY, RRF_SUBKEY_WOW6432KEY) für 64-Bit-Programme.

    #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;
    }

Diese Konsolen-App listet für die meisten potenziellen Registrierungswerte alle Werte und ihre Daten aus einem Registrierungsschlüssel auf.Es gibt einige seltsame, die nicht oft verwendet werden.Wenn Sie alle unterstützen müssen, erweitern Sie dieses Beispiel und verweisen Sie darauf Registrierungswerttyp Dokumentation.

Dies sei der Inhalt des Registrierungsschlüssels, den Sie aus einem importieren können .reg Datei Format:

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

Die Konsolen-App selbst:

#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;
}

Erwartete Konsolenausgabe:

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
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