LibCurl.Curl.internal_OnWriteCallback C# (CSharp) Method

        int internal_OnWriteCallback(IntPtr ptrBuffer, int sz, int nmemb, IntPtr ptrUserdata)
        {
            if (_OnWriteCallback != null)
            {
                int bytes = sz * nmemb;
                byte[] b = new byte[bytes];
                Marshal.Copy(ptrBuffer, b, 0, bytes);

                object userdata = GetObject(ptrUserdata);
                return _OnWriteCallback(b, bytes, userdata);
            }
            return 0;
        }