像这样调用下一个函数

byte[] m_Bytes = StreamHelper.ReadToEnd (mystream);

功能:

public static byte[] ReadToEnd(System.IO.Stream stream)
{
    long originalPosition = 0;

    if(stream.CanSeek)
    {
         originalPosition = stream.Position;
         stream.Position = 0;
    }

    try
    {
        byte[] readBuffer = new byte[4096];

        int totalBytesRead = 0;
        int bytesRead;

        while ((bytesRead = stream.Read(readBuffer, totalBytesRead, readBuffer.Length - totalBytesRead)) > 0)
        {
            totalBytesRead += bytesRead;

            if (totalBytesRead == readBuffer.Length)
            {
                int nextByte = stream.ReadByte();
                if (nextByte != -1)
                {
                    byte[] temp = new byte[readBuffer.Length * 2];
                    Buffer.BlockCopy(readBuffer, 0, temp, 0, readBuffer.Length);
                    Buffer.SetByte(temp, totalBytesRead, (byte)nextByte);
                    readBuffer = temp;
                    totalBytesRead++;
                }
            }
        }

        byte[] buffer = readBuffer;
        if (readBuffer.Length != totalBytesRead)
        {
            buffer = new byte[totalBytesRead];
            Buffer.BlockCopy(readBuffer, 0, buffer, 0, totalBytesRead);
        }
        return buffer;
    }
    finally
    {
        if(stream.CanSeek)
        {
             stream.Position = originalPosition; 
        }
    }
}

Byte[] Content = new BinaryReader(file.InputStream).ReadBytes(file.ContentLength);

"bigEnough" array is a bit of a stretch. Sure, buffer needs to be "big ebough" but proper design of an application should include transactions and delimiters. In this configuration each transaction would have a preset length thus your array would anticipate certain number of bytes and insert it into correctly sized buffer. Delimiters would ensure transaction integrity and would be supplied within each transaction. To make your application even better, you could use 2 channels (2 sockets). One would communicate fixed length control message transactions that would include information about size and sequence number of data transaction to be transferred using data channel. Receiver would acknowledge buffer creation and only then data would be sent. If you have no control over stream sender than you need multidimensional array as a buffer. Component arrays would be small enough to be manageable and big enough to be practical based on your estimate of expected data. Process logic would seek known start delimiters and then ending delimiter in subsequent element arrays. Once ending delimiter is found, new buffer would be created to store relevant data between delimiters and initial buffer would have to be restructured to allow data disposal.

只要代码转换流字节数组是一个下面。

Stream s = yourStream;
int streamEnd = Convert.ToInt32(s.Length);
byte[] buffer = new byte[streamEnd];
s.Read(buffer, 0, streamEnd);

我知道的最简单的解决方法是:

using(var memoryStream = new MemoryStream())
{
  sourceStream.CopyTo(memoryStream);
  return memoryStream.ToArray();
}

你也可以尝试一次只读入部分，并展开返回的字节数组:

public byte[] StreamToByteArray(string fileName)
{
    byte[] total_stream = new byte[0];
    using (Stream input = File.Open(fileName, FileMode.Open, FileAccess.Read))
    {
        byte[] stream_array = new byte[0];
        // Setup whatever read size you want (small here for testing)
        byte[] buffer = new byte[32];// * 1024];
        int read = 0;

        while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
        {
            stream_array = new byte[total_stream.Length + read];
            total_stream.CopyTo(stream_array, 0);
            Array.Copy(buffer, 0, stream_array, total_stream.Length, read);
            total_stream = stream_array;
        }
    }
    return total_stream;
}

快速和肮脏的技巧:

    static byte[] StreamToByteArray(Stream inputStream)
    {
        if (!inputStream.CanRead)
        {
            throw new ArgumentException(); 
        }

        // This is optional
        if (inputStream.CanSeek)
        {
            inputStream.Seek(0, SeekOrigin.Begin);
        }

        byte[] output = new byte[inputStream.Length];
        int bytesRead = inputStream.Read(output, 0, output.Length);
        Debug.Assert(bytesRead == output.Length, "Bytes read from stream matches stream length");
        return output;
    }

测试:

    static void Main(string[] args)
    {
        byte[] data;
        string path = @"C:\Windows\System32\notepad.exe";
        using (FileStream fs = File.Open(path, FileMode.Open, FileAccess.Read))
        {
            data = StreamToByteArray(fs);
        }

        Debug.Assert(data.Length > 0);
        Debug.Assert(new FileInfo(path).Length == data.Length); 
    }

我会问，为什么你要把一个流读到一个字节[]，如果你想复制一个流的内容，我可以建议使用MemoryStream和写你的输入流到内存流。