c# - 通过套接字发送大型序列化对象仅在尝试增加字节数组时失败，但在使用大量字节数组时没问题

Question

我有代码在通过套接字接收数据的同时尝试增加字节数组。这是错误的。

    public bool ReceiveObject2(ref Object objRec, ref string sErrMsg)
    {
        try
        {
            byte[] buffer = new byte[1024];
            byte[] byArrAll = new byte[0];
            bool bAllBytesRead = false;

            int iRecLoop = 0;

            // grow the byte array to match the size of the object, so we can put whatever we 
            // like through the socket as long as the object serialises and is binary formatted 
            while (!bAllBytesRead)
            {
                if (m_socClient.Receive(buffer) > 0)
                {
                    byArrAll = Combine(byArrAll, buffer);
                    iRecLoop++;
                }
                else
                {
                    m_socClient.Close();
                    bAllBytesRead = true;
                }
            }

            MemoryStream ms = new MemoryStream(buffer);
            BinaryFormatter bf1 = new BinaryFormatter();
            ms.Position = 0;
            Object obj = bf1.Deserialize(ms);
            objRec = obj;

            return true;
        }
        catch (System.Runtime.Serialization.SerializationException se)
        {
            objRec = null;
            sErrMsg += "SocketClient.ReceiveObject " + "Source " + se.Source + "Error : " + se.Message;
            return false;
        }
        catch (Exception e)
        {
            objRec = null;
            sErrMsg += "SocketClient.ReceiveObject " + "Source " + e.Source + "Error : " + e.Message;
            return false;
        }
    }

    private byte[] Combine(byte[] first, byte[] second)
    {
        byte[] ret = new byte[first.Length + second.Length];
        Buffer.BlockCopy(first, 0, ret, 0, first.Length);
        Buffer.BlockCopy(second, 0, ret, first.Length, second.Length);
        return ret;
    }    

错误:mscorlibError:输入流不是有效的二进制格式。起始内容(以字节为单位)为:68-61-73-43-68-61-6E-67-65-73-3D-22-69-6E-73-65-72 ...

然而，当我只是作弊并使用 MASSIVE 缓冲区大小时，它没问题。

        public bool ReceiveObject(ref Object objRec, ref string sErrMsg)
    {
        try
        {
            byte[] buffer = new byte[5000000];

            m_socClient.Receive(buffer);
            MemoryStream ms = new MemoryStream(buffer);
            BinaryFormatter bf1 = new BinaryFormatter();

            ms.Position = 0;
            Object obj = bf1.Deserialize(ms);
            objRec = obj;

            return true;
        }
        catch (Exception e)
        {
            objRec = null;
            sErrMsg += "SocketClient.ReceiveObject " + "Source " + e.Source + "Error : " + e.Message;
            return false;
        }
    }

这真的让我很生气。我不知道为什么它不起作用。我也从此处的建议中取消了联合收割机，所以我很确定这没有做错事？

希望有人能指出我哪里不对

Answer 1

Combine 方法是增长数组的一种非常昂贵的方法，尤其是当MemoryStream 设计 来解决这个问题时；其他回复是正确的:您必须检查读取的字节数:

using(MemoryStream ms = new MemoryStream()) {
    int bytesRead;
    while((bytesRead = m_socClient.Receive(buffer)) > 0) {
        ms.Write(buffer, 0, bytesRead);
    }
    // access ms.ToArray() or ms.GetBuffer() as desired, or
    // set Position to 0 and read
}

当然，您可以直接从流中读取(将其传递给您的阅读器)

此外 - 如果您的序列化太大，您可以考虑使用其他编码器，例如 protobuf-net(尽管这会稍微更改代码)。这可能会解决大型对象的问题。