Convert chinese error message to String^ in managed C++

Question

I have a dll from a company called CTP that allows me to trade on Chinese exchanges. It is in C++ and my app is in C#... I have been able to write code that uses managed C++ to link to the dll and translate strings (ascii) and other parameters from C# to and from the dll. The only problem is when I get error messages back from the dll they are in Chinese. And I am having trouble translating the char* I get back into a valid String^ that contains good Chinese characters.

For example, the following char* message array:

43 54 50 3A CE DE B4 CB C8 A8 CF DE 00

using this code:

return gcnew String^(message);

I get "CTP:ÎÞ´ËȨÏÞ".

using this code:

int bufSize = MultiByteToWideChar(CP_UTF8, 0, message, -1, NULL, 0);
wchar_t* wstr = new wchar_t[bufSize];
MultiByteToWideChar(CP_UTF8, 0, message, -1, wstr, bufSize);
String^ val = gcnew String(wstr);
delete[] wstr;
return val;

I get "CTP:�޴�Ȩ��".

Further, when I try to run that text string through online hex -> UTF8 converters I get an error message that the utf8 string is invalid.

I am very sure that the first four characters are "CTP:" as this is the name of the company that wrote the dll.

However, I cannot figure out how the Chinese characters that follow are encoded. Any ideas?

Answer 1

Ok... so the encoding is GB18030 or "code page" 54936... so the following code converted the string properly. Not sure if there is a #define for GB18030 or not.

System::String^ CTPTraderWrapper::GetString(char* message)
{
    int bufSize = MultiByteToWideChar(54936, 0, message, -1, NULL, 0);
    wchar_t* wstr = new wchar_t[bufSize];
    MultiByteToWideChar(54936, 0, message, -1, wstr, bufSize);
    String^ val = gcnew String(wstr);
    delete[] wstr;
    return val;
}