无法使用 swprintf 在 WCHAR* 中打印 char*

Question

我有这个功能（我只需要在最后将字符串转换为 WHAT*）：

wstring stringtowstring(string str)
{
    WCHAR ch[256];
    MultiByteToWideChar(CP_ACP, 0, str.c_str(), -1, (LPWSTR)ch, 256);

    return wstring(ch);
}

但我想知道为什么没有：

WCHAR tmp[256];
swprintf(tmp, L"%s", "test");

Answer 1

假设在上下文中 Visual Studio，这是 swprintf 的 documented non-standard behavior。

Character and string arguments that are specified by using c and s are interpreted as char and char* by printf family functions, or as wchar_t and wchar_t* by wprintf family functions. Character and string arguments that are specified by using C and S are interpreted as wchar_t and wchar_t* by printf family functions, or as char and char* by wprintf family functions. This behavior is Microsoft-specific.

Microsoft-specific: The Z type character, and the behavior of the c, C, s, and S type characters when they are used with the printf and wprintf functions, are Microsoft extensions. The ISO C standard uses c and s consistently for narrow characters and strings, and C and S for wide characters and strings, in all formatting functions.

无法使用 swprintf 在 WCHAR* 中打印 char*

Can't print char* in WCHAR* with swprintf

c++

wchar