Question

The problem below is ralated to my previous question

Converting static link library to dynamic dll

My first step was to develop a dll, that was done. (Thanks John Knoeller prakash. Your input was very helpful)

Now when i call the function in the dll from my c# application i get the error

“Attempted to read or write protected memory. This is often an indication that other memory is corrupt.”

Here is the C++ definition

 extern "C" DEMO2_API void Decompress(char* inp_buff, unsigned short* 
 inp_len, char* buffer_decomp,unsigned *output_len,unsigned short* errorCode);

My C# Converstion p/Involke

   private static extern void Decompress(
        byte[] inp_buff,
        ref ushort inp_len,
        byte[] buffer_decomp,
        ref int output_len,
        ref ushort errorCode
        );        

And I am calling it as below

    byte[] dst = new byte[2048];
    int outlen = 2048;
    ushort errorCode = 0;
    Decompress(src, (ushort )src.Length, dst, ref outlen,ref errorCode);
    return dst;

What is wrong?

Answer 1

The 4th parameter need to be passed using out mode instead of ref. That solved the problem.