Question

Hi I’m developing an client application in C# and the server is written in c++

the server uses:

inline void StrToInts(int *pInts, int Num, const char *pStr)
{
  int Index = 0;
  while(Num)
  {
    char aBuf[4] = {0,0,0,0};
    for(int c = 0; c < 4 && pStr[Index]; c++, Index++)
      aBuf[c] = pStr[Index];
    *pInts = ((aBuf[0]+128)<<24)|((aBuf[1]+128)<<16)|((aBuf[2]+128)<<8)|(aBuf[3]+128);
    pInts++;
    Num--;
  }

  // null terminate
  pInts[-1] &= 0xffffff00;
}

to convert an string to int[]

in my c# client i recieve:

int[4] { -14240, -12938, -16988, -8832 }

How do I convert the array back to an string?
I don’t want to use unsafe code (e.g. pointers)
Any of my tries resulted in unreadable strings.

EDIT:
Here is one of my approch:

private string IntsToString(int[] ints)
{
  StringBuilder s = new StringBuilder();
  for (int i = 0; i < ints.Length; i++)
  {
    byte[] bytes = BitConverter.GetBytes(ints[i]);
    for (int j = 0; j < bytes.Length; j++)
      s.Append((char)(bytes[j] & 0x7F));
  }
  return s.ToString();
}

I know I need to take care of endianess but as the server is running on my local machine and the server too, I assume that this is not a problem.
My other try was to use an struct with explicit layout and same FieldOffset for integer and chars but it doesn’t work, either.

Answer 1

Maybe try something like (using LINQ):

int[] fromServer = { -14240, -12938, -16988, -8832, };

string reconstructedStr = new string(fromServer.SelectMany(BitConverter.GetBytes).Select(b => (char)(b - 128)).ToArray());

Untested, but there’s something to start from. Don’t know if the subtraction of 128 is correct.