Question

System.IO.BinaryReader reads values in a little-endian format.

I have a C# application connecting to a proprietary networking library on the server side. The server-side sends everything down in network byte order, as one would expect, but I find that dealing with this on the client side is awkward, particularly for unsigned values.

UInt32 length = (UInt32)IPAddress.NetworkToHostOrder(reader.ReadInt32()); 

is the only way I’ve come up with to get a correct unsigned value out of the stream, but this seems both awkward and ugly, and I have yet to test if that’s just going to clip off high-order values so that I have to do fun BitConverter stuff.

Is there some way I’m missing short of writing a wrapper around the whole thing to avoid these ugly conversions on every read? It seems like there should be an endian-ness option on the reader to make things like this simpler, but I haven’t come across anything.

Answer 1

There is no built-in converter. Here’s my wrapper (as you can see, I only implemented the functionality I needed but the structure is pretty easy to change to your liking):

/// <summary> /// Utilities for reading big-endian files /// </summary> public class BigEndianReader {     public BigEndianReader(BinaryReader baseReader)     {         mBaseReader = baseReader;     }      public short ReadInt16()     {         return BitConverter.ToInt16(ReadBigEndianBytes(2), 0);     }      public ushort ReadUInt16()     {         return BitConverter.ToUInt16(ReadBigEndianBytes(2), 0);     }      public uint ReadUInt32()     {         return BitConverter.ToUInt32(ReadBigEndianBytes(4), 0);     }      public byte[] ReadBigEndianBytes(int count)     {         byte[] bytes = new byte[count];         for (int i = count - 1; i >= 0; i--)             bytes[i] = mBaseReader.ReadByte();          return bytes;     }      public byte[] ReadBytes(int count)     {         return mBaseReader.ReadBytes(count);     }      public void Close()     {         mBaseReader.Close();     }      public Stream BaseStream     {         get { return mBaseReader.BaseStream;  }     }      private BinaryReader mBaseReader; } 

Basically, ReadBigEndianBytes does the grunt work, and this is passed to a BitConverter. There will be a definite problem if you read a large number of bytes since this will cause a large memory allocation.