Unmanged to managed

Question

I would appreciate if someone could provide some information on passing string value from a unmanaged C++ code to a equuivalent managed string object? .

When passed as a Func(const char * s) from unmanaged c++ code and try to access the Func from c# ,the signature changes to Func(sbyte*) .

Prashant · Answer

Hello Alan  Thanks a lot for your reply . Not exactly what i wanted . I have a unmanaged C++ class and i am creating a wrapper class for it  where one of my function takes a parameter as (const char *s) ex :- func(const char *s){ } . The wrapper what i have created is a dll application and when i import the dll into my c# application the signature changes to func (sbyte*) whereas i need something like func(string) in my c# application...Hope it clarifies the problem .

Alan · Answer

If I've understood that correctly it looks like you're going to have to convert a managed string to an sbyte* before you can call the unmanaged function from C#. This short program illustrates the principle: using System; unsafe class Program { static void Main() { string s = Hello; // needs to be plain ascii chars 0 - 127 sbyte[] sba = new sbyte[s.Length + 1]; // including final null byte for(int i = 0; i { sba[i] = (sbyte)s[i]; } fixed(sbyte* sbp = sba) { Func(sbp); } Console.WriteLine(); Console.ReadLine(); } static void Func(sbyte* sbp) { int count = 0; while(sbp[count] != 0) Console.Write((char)sbp[count++]); } }