public static extern int WideCharToMultiByte(int codePage, CharConversionFlags flags, [MA(UT.LPWStr)] string wideStr, int chars, [In, Out] byte[] pOutBytes, int bufferBytes, IntPtr defaultChar, IntPtr pDefaultUsed);
public static extern int MultiByteToWideChar(int codePage, CharConversionFlags dwFlags, byte[] lpMultiByteStr, int cchMultiByte, [Out, MA(UT.LPWStr)] StringBuilder lpWideCharStr, int cchWideChar);