問題描述

給定某些注冊表值的鍵(例如 HKEY_LOCAL_MACHINElahlahlahfoo)，我該如何:

Given the key for some registry value (e.g. HKEY_LOCAL_MACHINElahlahlahfoo) how can I:

1. 安全地確定存在這樣的密鑰.
2. 以編程方式(即使用代碼)獲取其值.

我絕對無意將任何內(nèi)容寫回注冊表(如果可以的話，在我的職業(yè)生涯中).因此，如果我錯誤地寫入注冊表，我們可以跳過關于我體內(nèi)每個分子以光速爆炸的講座.

I have absolutely no intention of writing anything back to the registry (for the duration of my career if I can help it). So we can skip the lecture about every molecule in my body exploding at the speed of light if I write to the registry incorrectly.

更喜歡 C++ 中的答案，但大多數(shù)情況下只需要知道獲得該值的特殊 Windows API 咒語是什么.

Prefer answers in C++, but mostly just need to know what the special Windows API incantation to get at the value is.

推薦答案

這里是一些偽代碼來檢索以下內(nèi)容:

1. 如果注冊表項存在
2. 該注冊表項的默認值是什么
3. 什么是字符串值
4. 什么是 DWORD 值

示例代碼:

包含庫依賴:Advapi32.lib

Include the library dependency: 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;
}

這篇關于如何從 Windows 注冊表中讀取值的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！