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对注册表值使用RegQueryValueEx,该注册表值可以是REG\U DWORD或REG\U SZ

registry windows c++

David · 技术社区 · 9 年前

RegQueryValueEx() 检索可能写入 REG_SZ 或 REG_DWORD

BYTE byteArray[MAX];
DWORD dataSize = sizeof(byteArray);
DWORD type = 0;
RegQueryValueEx(
        hKey,
        subKey,
        nullptr,
        &type,
        reinterpret_cast<BYTE*>(&byteArray),
        &dataSize));

当我得到一个 REG_SZ公司

byteArray   0x004fe6a8 "4"  unsigned char[100]
    [0] 52 '4'  unsigned char
    [1] 0 '\0'  unsigned char
    [2] 50 '2'  unsigned char
    [3] 0 '\0'  unsigned char
    [4] 51 '3'  unsigned char
    [5] 0 '\0'  unsigned char
    [6] 49 '1'  unsigned char
    [7] 0 '\0'  unsigned char
    [8] 52 '4'  unsigned char
    [9] 0 '\0'  unsigned char
    [10]0 '\0'  unsigned char

有没有办法在每个字符后都不能有空字节?我想是因为 RegEnumValue() 每个角色都被调用,但我不确定。

1 回复 | 直到 9 年前

Remy Lebeau 9 年前

你的问题与 RegEnumValue() .

你的应用正在调用 TCHAR -基于 RegQueryValueEx() ,它实际上是一个预处理器宏,映射到 RegQueryValueExA() (ANSI)或 RegQueryValueExW() (Unicode),取决于 UNICODE

RegQueryValueXw() 以UTF-16LE格式的Unicode文本形式返回字符串数据,这正是您在缓冲区中看到的,因此很明显,您的应用程序是为Unicode编译的。你看到的是完全正常的行为。

BYTE byteArray[MAX];
DWORD dataSize = sizeof(byteArray);
DWORD type = 0;
if (RegQueryValueEx( // <-- calling the TCHAR version!
    hKey,
    subKey,
    nullptr,
    &type,
    reinterpret_cast<BYTE*>(&byteArray),
    &dataSize) == 0)
{
    switch (type)
    {
        case REG_DWORD:
        {
            LPDWORD value = reinterpret_cast<LPDWORD>(&byteArray);
            // use *value as needed ...
            break;
        }

        case REG_SZ:
        case REG_MULTI_SZ:
        case REG_EXPAND_SZ:
        {
            // note the T in LPTSTR!  That means 'TCHAR' is used...
            LPTSTR text = reinterpret_cast<LPTSTR>(&byteArray);
            // use text as needed, up to (dataSize/sizeof(TCHAR)) number
            // of TCHARs. This is because RegQueryValueEx() does not
            // guarantee the output data has a null terminator.  If you
            // want that, use RegGetValue() instead...
            break;
        }
    }
}

或:

BYTE byteArray[MAX];
DWORD dataSize = sizeof(byteArray);
DWORD type = 0;
if (RegQueryValueExW( // <-- calling the UNICODE version!
    hKey,
    subKey,
    nullptr,
    &type,
    reinterpret_cast<BYTE*>(&byteArray),
    &dataSize) == 0)
{
    switch (type)
    {
        case REG_DWORD:
        {
            LPDWORD value = reinterpret_cast<LPDWORD>(&byteArray);
            // use *value as needed ...
            break;
        }

        case REG_SZ:
        case REG_MULTI_SZ:
        case REG_EXPAND_SZ:
        {
            // note the W in LPWSTR!  That means 'WCHAR' is used...
            LPWSTR text = reinterpret_cast<LPWSTR>(&byteArray);
            // use text as needed, up to (dataSize/sizeof(WCHAR)) number
            // of WCHARs. This is because RegQueryValueExW() does not
            // guarantee the output data has a null terminator.  If you
            // want that, use RegGetValueW() instead...
            break;
        }
    }
}

将其读取为Unicode后进行转换,例如使用 WideCharToMultiByte() 或等效。

使用 RegQueryValueExA() (或 RegGetValueA()

REG_SZ REG_MULTI_SZ 或 REG_EXPAND_SZ RegQueryValueExA 或者不定义 UNICODE 在包括 Windows.h 该函数将存储的Unicode字符串转换为ANSI字符串,然后将其复制到 lpData .

BYTE byteArray[MAX];
DWORD dataSize = sizeof(byteArray);
DWORD type = 0;
if (RegQueryValueExA( // <-- calling the ANSI version
    hKey,
    subKey,
    nullptr,
    &type,
    reinterpret_cast<BYTE*>(&byteArray),
    &dataSize) == 0)
{
    switch (type)
    {
        case REG_DWORD:
        {
            LPDWORD value = reinterpret_cast<LPDWORD>(&byteArray);
            // use *value as needed ...
            break;
        }

        case REG_SZ:
        case REG_MULTI_SZ:
        case REG_EXPAND_SZ:
        {
            // note the lack of T in LPSTR! That means 'char' is used...
            LPSTR text = reinterpret_cast<LPSTR>(&byteArray);
            // use text as needed, up to dataSize number of chars. This
            // is because RegQueryValueExA() does not guarantee the
            // output data has a null terminator.  If you want that,
            // use RegGetValueA() instead...
            break;
        }
    }
}

无论是哪种方式,只要注意,您都有可能丢失您决定转换为的目标字符集中不存在的任何非ASCII字符。因此,最好坚持使用Unicode,并按如下方式处理缓冲区数据 WCHAR 数据(什么 TCHAR公司 映射到何时