在运行时，如何告诉我是否在WinXP +？ win32 [英] at runtime, how can I tell if I'm on WinXP+? win32

问题描述

我正在做一些win32字符串API调用，并假设字符串出来作为宽字符串，这是有效的XP和更新。我如何断言这个？这是一个运行时检查还是编译时检查？

I'm making some win32 string API calls and am assuming that the strings come out as wide strings, which is valid on XP and newer. How can I assert this? Is this a runtime check or a compile-time check?

我做错了吗？这里有一个例子：

Am I doing it wrong? Here's an example:

typedef std::basic_string<TCHAR> TString;
inline TString queryRegStringValue(HKEY key, const TString& subkey, 
        const TString defaultValue = TEXT(""))
{
    std::vector<char> out_bytes(256);
    DWORD num_bytes = out_bytes.size();
    DWORD out_type;
    long retval = RegQueryValueEx(key, subkey.c_str(), 0, &out_type, 
        reinterpret_cast<BYTE*>(&out_bytes[0]), &num_bytes); //comes out as a platform string. wide on XP
    if (retval != 0)
        return defaultValue;
    if (num_bytes > 0)
    {
        assert(out_type == REG_SZ);
        BOOST_STATIC_ASSERT(sizeof(TCHAR)==2); //what if someone runs my code on an older system?
        return TString(reinterpret_cast<wchar_t*>(&out_bytes[0]), num_bytes/2); //assumes windows XP (wide string)
    }

    return TEXT("");
}

推荐答案

。 Windows已经是过去17年的一个本地Unicode操作系统，早在XP发布之前。

It is a non-issue. Windows has been a native Unicode operating system for the past 17 years, long before XP was released. David Cutler's brain child, NT 3.1, was Unicode from day one.

在不太可能的情况下，你的程序落在Window 9x机器上，还有一个API层，可以将您的UTF-16字符串转换为8位字符。使用TCHAR进行新代码开发没有任何意义。

In the unlikely case that your program lands on a Window 9x machine, there's still an API layer that can translate your UTF-16 strings to 8-bit chars. There's no point left in using TCHAR for new code development.

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