C# TcpClient发送世界信息时异常关闭Server上的连接

Question

我试图通过与服务器上的客户端连接的 NetworkStream 发送我的世界中的所有图块（称为粒子，不要将它们与客户端粒子效果混淆）（我的世界类中的 500x350 二维数组）和客户端。

代码如下：

public int ServerSendWorldData(NetworkStream networkStream, Point from, Point size, bool reportBytesSent, Networking.Client toClient)
    {
        int bytesOfAcknowledgementSent = 0;
        int totalBytesSent = 0;
        int tilesSentThisAcknowledgement = 0;
        int tilesToSendForThisAcknowledgement = 20;

        for (int x = from.X; x < size.X; x++)
        {
            for (int y = from.Y; y < size.Y; y++)
            {
                Thread.Sleep(0);

                //Handle acknowledgement if needed.
                if (tilesSentThisAcknowledgement >= tilesToSendForThisAcknowledgement)
                {
                    //Wait for Client acknowledgement.
                    bytesOfAcknowledgementSent += Networking.NetworkingHelp.SendMessageFromByte((byte)Networking.MessageType.ServerSendWorldMapDataWaitAcknowledgement, networkStream);

                    //Handle here.
                    if (networkStream.ReadByte() == (byte)Networking.MessageType.ClientAcknowledgeWorldMapData)
                        tilesSentThisAcknowledgement = 0;
                    else
                        throw new Exception("Client did not acknowledge data!");
                }

                if (world.worldParticles[x, y] != null)
                {
                    //Send Particle Data
                    totalBytesSent += Networking.NetworkingHelp.SendMessageFromByte((byte)Networking.MessageType.ServerSendWorldMapDataParticle, networkStream);
                    totalBytesSent += Networking.NetworkingHelp.SendMessageFromInt(x, networkStream);
                    totalBytesSent += Networking.NetworkingHelp.SendMessageFromInt(y, networkStream);
                    totalBytesSent += Networking.NetworkingHelp.SendMessageFromInt(world.worldParticles[x, y].ID, networkStream);
                    //totalBytesSent += Networking.NetworkingHelp.SendMessageFromInt(world.worldParticles[x, y].spriteIndex, networkStream);
                    totalBytesSent += Networking.NetworkingHelp.SendMessageFromBool(world.worldParticles[x, y].draw, networkStream);
                    totalBytesSent += Networking.NetworkingHelp.SendMessageFromBool(world.worldParticles[x, y].collisionWithEntities, networkStream);

                    tilesSentThisAcknowledgement++;
                }
            }
        }

        if (reportBytesSent)
        {
            Statistics.Console.WriteLine("Sent " + totalBytesSent + " bytes of World data to Client " + toClient.name + " and " + bytesOfAcknowledgementSent + " bytes of acknowledgement was exchanged!");
        }

        return totalBytesSent;
    }

NetworkingHelp 类基本上只是 networkStream.Write，使用 BitConverter 将数据（如整数）转换为字节，或者使用 Encoding 将数据（如字符串）转换为 UTF8 中的字节。

该代码总共向客户端发送 0.76 MB 的地图数据。

使用 localhost / IPAddress.Loopback 连接到服务器时，不存在我遇到的问题，但通过互联网向客户端发送数据时出现问题 - 数据发送速度非常慢（可能是由于文件大小，我是虽然不确定）并且没有“处理确认”位代码……

            //Handle acknowledgement if needed.
            if (tilesSentThisAcknowledgement >= tilesToSendForThisAcknowledgement)
            {
                //Wait for Client acknowledgement.
                bytesOfAcknowledgementSent += Networking.NetworkingHelp.SendMessageFromByte((byte)Networking.MessageType.ServerSendWorldMapDataWaitAcknowledgement, networkStream);

                //Handle here.
                if (networkStream.ReadByte() == (byte)Networking.MessageType.ClientAcknowledgeWorldMapData)
                    tilesSentThisAcknowledgement = 0;
                else
                    throw new Exception("Client did not acknowledge data!");
            }

客户端收到大约 20 个世界图块并抛出异常“无法将数据写入传输连接：现有连接被远程强制关闭” host”，这似乎发生是因为客户端收到一条 1 字节消息，其中字节 0 作为其内容。

看来“处理确认”代码创建的暂停解决了这个问题，但使世界数据传输速度变慢了很多。

非常感谢您的帮助，我知道我的代码有点混乱（欢迎有关如何改进它的建议，这是我第一次发送这么多数据）。这是用于读取客户端特定消息的代码块。

        //WorldParticlesMapDataParticle
        else if (recievedMessage[0] == (byte)Networking.MessageType.ServerSendWorldMapDataParticle)
        {
            //Read the position of the new data.
            recievedMessageBytes = networkStream.Read(recievedMessage, 0, 4);
            int newParticleX = BitConverter.ToInt32(recievedMessage, 0);
            recievedMessageBytes = networkStream.Read(recievedMessage, 0, 4);
            int newParticleY = BitConverter.ToInt32(recievedMessage, 0);

            //Read the particle ParticleID.
            recievedMessageBytes = networkStream.Read(recievedMessage, 0, 4);
            int newParticleID = BitConverter.ToInt32(recievedMessage, 0);

            //Read the particle SpriteID.
            //recievedMessageBytes = networkStream.Read(recievedMessage, 0, 4);
            //int newSpriteID = BitConverter.ToInt32(recievedMessage, 0);

            //Read the particle draw.
            recievedMessageBytes = networkStream.Read(recievedMessage, 0, 1);
            bool newParticleDraw = BitConverter.ToBoolean(recievedMessage, 0);

            //Read the particle collision.
            recievedMessageBytes = networkStream.Read(recievedMessage, 0, 1);
            bool newParticleCollision = BitConverter.ToBoolean(recievedMessage, 0);

            //Set particle.
            try
            {
                world.worldParticles[newParticleX, newParticleY] = World.Particle.ParticleManager.particleArray[newParticleID];
                //world.worldParticles[newParticleX, newParticleY].spriteIndex = newSpriteID;
                world.worldParticles[newParticleX, newParticleY].draw = newParticleDraw;
                world.worldParticles[newParticleX, newParticleY].collisionWithEntities = newParticleCollision;
            }
            catch (Exception ex)
            {
                Statistics.Console.WriteLine("Server requested new Particle at " + newParticleX + "," + newParticleY + ", but Client failed to place it due to an exception : " + ex.Message);

                try
                {
                    world.worldParticles[newParticleX, newParticleY] = null;
                }
                catch
                { }
            }
        }

Answer 1

您忽略 NetworkStream.Read 的返回值。我认为您假设它总是会读取您要求它读取的字节数，除非出现错误。事实上，您指定的字节数只是它将读取的最大字节数，并且它不会读取比您调用它时当前可用的字节数更多的字节。

“此方法将数据读取到缓冲区参数中，并返回成功读取的字节数。如果没有数据可供读取，则 Read 方法返回 0。Read 操作会读取尽可能多的可用数据，最多可达数量由大小参数指定的字节数。如果远程主机关闭连接，并且已接收到所有可用数据，则 Read 方法立即完成并返回零字节。” - NetworkStream.Read

您已创建假设 TCP 会以某种方式将数据“粘合在一起”，只是因为您在一次调用中发送了数据，这是一个典型的错误。事实上TCP没有这样的机制。

Answer 2

您一次发送一个粒子，尝试制作一大堆您想要发送的内容，并将其分成一个块发送

Answer 3

为了补充 David Schwartz 的答案，您最好阅读 Stephen Cleary 的 TCP /IP 常见问题解答，尤其是 消息框架部分