How to import const char* API to C#?

Question

Given this C API declaration how would it be imported to C#?

const char* _stdcall z4LLkGetKeySTD(void);

I\'ve been able to get this far:

Answer 1

Always use C++ const char* or char* and not std::string.

Also keep in mind that char in C++ is a sbyte in C# and unsigned char is a byte in C#.

It is advisable to use unsafe code when dealing with DllImport.

[DllImport("zip4_w32.dll",
   CallingConvention = CallingConvention.StdCall,
   EntryPoint = "z4LLkGetKeySTD",
   ExactSpelling = false)]
 private extern static sbyte* or byte* z4LLkGetKeySTD();

 void foo()
 {
   string res = new string(z4LLkGetKeySTD());
 }