Question

I’m trying to get a byte[] array filled with request response, without any extra garbage data.

This is how I fetch the data:

using (Stream MyResponseStream = hwresponse.GetResponseStream())
{
    byte[] MyBuffer = new byte[4096];
    int BytesRead;

    while (0 < (BytesRead = MyResponseStream.Read(MyBuffer, 0, MyBuffer.Length)))
    {
        ByteArrayToFile("request.txt", MyBuffer);
    }
}

I use the function ‘ByteArrayToFile’ to see what data has been recieved.

public void ByteArrayToFile(string _FileName, byte[] _ByteArray)
{
    System.IO.FileStream _FileStream = new System.IO.FileStream(_FileName, System.IO.FileMode.Append, System.IO.FileAccess.Write);
    _FileStream.Write(_ByteArray, 0, _ByteArray.Length);
    _FileStream.Close();
}

I get request written to the file, but a lot of ‘null’ characters are added at the end. How do I trim them? Since I’m going to need this to handle binary files, how can I safely trim out the endings and have just pure array of response? Thanks!

Answer 1

You need to utilise the value BytesRead, this will indicate exactly how many bytes were received:

public void ByteArrayToFile(string _FileName, byte[] _ByteArray, int _BytesRead)
{
    using (var _FileStream = new FileStream(
      _FileName, FileMode.Append, FileAccess.Write))
    { 
        _FileStream.Write(_ByteArray, 0, _BytesRead);
    }
}

Otherwise you’re writing out an array of length X which has only been populated with Y number of elements, causing a number of ‘unused’ elements in the array to also be written out. There is also the possibility of stale data remaining in the buffer with a pass, meaning misinformation could also end up being written out with the next write.

You should also dispose of FileStream instances when done (although Close does this for a Stream, I’d recommend the consistency of calling Dispose in one of two ways: explicitly or as illustrated in the code above, implicitly using the using construct).