System.Net.WebUtility.GetEncodedBytes C# (CSharp) Method

        private static void GetEncodedBytes(byte[] originalBytes, int offset, int count, byte[] expandedBytes)
        {
            int pos = 0;
            int end = offset + count;
            Debug.Assert(offset < end && end <= originalBytes.Length);
            for (int i = offset; i < end; i++)
            {
#if DEBUG
                // Make sure we never overwrite any bytes if originalBytes and
                // expandedBytes refer to the same array
                if (originalBytes == expandedBytes)
                {
                    Debug.Assert(i >= pos);
                }
#endif

                byte b = originalBytes[i];
                char ch = (char)b;
                if (IsUrlSafeChar(ch))
                {
                    expandedBytes[pos++] = b;
                }
                else if (ch == ' ')
                {
                    expandedBytes[pos++] = (byte)'+';
                }
                else
                {
                    expandedBytes[pos++] = (byte)'%';
                    expandedBytes[pos++] = (byte)IntToHex((b >> 4) & 0xf);
                    expandedBytes[pos++] = (byte)IntToHex(b & 0x0f);
                }
            }
        }