将Platform::String转换为std::String

编辑:请参见 this answer 以获得更好的便携式解决方案。

问题是 std::string 仅保存8位字符数据 Platform::String^ 保存Unicode数据。Windows提供功能 WideCharToMultiByte 和 MultiByteToWideChar 来回转换:

std::string make_string(const std::wstring& wstring)
{
  auto wideData = wstring.c_str();
  int bufferSize = WideCharToMultiByte(CP_UTF8, 0, wideData, -1, nullptr, 0, NULL, NULL);
  auto utf8 = std::make_unique<char[]>(bufferSize);
  if (0 == WideCharToMultiByte(CP_UTF8, 0, wideData, -1, utf8.get(), bufferSize, NULL, NULL))
    throw std::exception("Can't convert string to UTF8");

  return std::string(utf8.get());
}

std::wstring make_wstring(const std::string& string)
{
  auto utf8Data = string.c_str();
  int bufferSize = MultiByteToWideChar(CP_UTF8, 0, utf8Data, -1, nullptr, 0);
  auto wide = std::make_unique<wchar_t[]>(bufferSize);
  if (0 == MultiByteToWideChar(CP_UTF8, 0, utf8Data, -1, wide.get(), bufferSize))
    throw std::exception("Can't convert string to Unicode");

  return std::wstring(wide.get());
}

void Test()
{
  Platform::String^ str = L"विकास, વિકાસ, ਵਿਕਾਸ, Vikas";
  std::wstring wsstr(str->Data());
  auto utf8Str = make_string(wsstr); // UTF8-encoded text
  wsstr = make_wstring(utf8Str); // same as original text
}

使用C++,您可以从 Platform::String 到 std::string 具有以下代码:

Platform::String^ fooRT = "aoeu";
std::wstring fooW(fooRT->Begin());
std::string fooA(fooW.begin(), fooW.end());

参考: How to convert Platform::String to char*?