Pass C# byte[] to C++ as Unsigned Char[]

You can add a C++/CLI class with a function that takes a .NET String and call the detdata function. In that method, you can use marshal_as to convert the string. Something like:

#include <string>

#include <msclr\marshal_cppstd.h>

using namespace msclr::interop;

void detdata(unsigned char _data[]);

public ref class Class1
{
public:
	Class1(void) {}

	void f1(System::String^ str)
	{					
		std::string data = marshal_as<std::string>(str);
		detdata((unsigned char*)data.c_str());
	}
};

Then, you can use the f1 function in your C# code. Something like:

Class1 c1 = new Class1();
c1.f1("Text 1");
c1.f1("Text 2");
c1.f1("Text 3");

void Convert(String^ Data)
        {
            unsigned char array[28];

            array<String^>^ strArray = gcnew array<String^>(28);
            strArray = Data->Split(',');

            int val = 0, index = 0;

            for each (String^ value in strArray)
            {
                val = int::Parse(value);
                array[index] = val;
                index++;
            }
        }