该函数用于注册预制体，所有需要利用Mirror进行动态生成单位，都需要完成预制体的注册，有两种方式一种是在NetworkManager中RegisteredSpawnablePrefabs列表中添加对应的预制体，要添加成功需要该预制体存在NetworkIdentify组件，否则无法添加，也可以点击Inspector界面的PopulateSpawnablePrefabs，该功能可以自动扫描当前项目中所有添加了NetworkIdentify的预制体,能够自动将预制体添加到列表中，这里很容易犯一个小错误，如果预制体的名字一致，但是错误提示没有注册，可以检查是否是名字一样实则不同的预制体，方式二就是点在运行期间通过

RegisterPrefab (GameObject prefab, Guid newAssetId, SpawnHandlerDelegate spawnHandler, UnSpawnDelegate unspawnHandler)

该方法进行注册，需要注意的是注册的预制体需要在各个端都存在，否则注册之后会出问题。后面的SpawnHander UnSpawnDelegate 可以拦截系统的Spawn 和UnSpawn事件，找一个很容易理解的例子 Instantiate (实例化)Desotry (销毁)。客户端在收到UnSpawn默认的行为是Desotry掉，如果想要池化联网对象，就需要依靠上面的SpawnHander方法，另外该方法一个AssetId只能调用一次，不可以重复调用，如果需要替换请使用其他方法，该方法还有其他的重载，想要细致了解的化可以查看官方文档

链接远程服务器，address地址通过是一个ip，具体的端口信息在Transport.active中持有，通过这种方式可以修改端口，也就说明了Transport.active是单例的

    if (Transport.active is PortTransport portTransport)
    {
        // use TryParse in case someone tries to enter non-numeric characters
        portTransport.Port = ushort.Parse(port);
    }

根据源码具体看看这部分是怎么做的

     public static void Connect(string address)
     {
         Initialize(false);

         AddTransportHandlers();//
         connectState = ConnectState.Connecting;
         Transport.active.ClientConnect(address);
         connection = new NetworkConnectionToServer();
     }

Transport是一个接口interface，不同的传续协议都会实现，这里我们抽一个KcpTransport看一下

//KcpTransport.cs#ClientConnect

public override void ClientConnect(string address)
{
    client.Connect(address, Port);
}
//KcpConnect.cs#ClientConnect
 public void Connect(string address, ushort port)
 {
     if (connected)
     {
         Log.Warning("[KCP] Client: already connected!");
         return;
     }

     // resolve host name before creating peer.
     // fixes: https://github.com/MirrorNetworking/Mirror/issues/3361
     if (!Common.ResolveHostname(address, out IPAddress[] addresses))
     {
         // pass error to user callback. no need to log it manually.
         OnError(ErrorCode.DnsResolve, $"Failed to resolve host: {address}");
         OnDisconnectedCallback();
         return;
     }

     // create fresh peer for each new session
     // client doesn't need secure cookie.
     Reset(config);

     Log.Info($"[KCP] Client: connect to {address}:{port}");

     // create socket
     remoteEndPoint = new IPEndPoint(addresses[0], port);
     socket = new Socket(remoteEndPoint.AddressFamily, SocketType.Dgram, ProtocolType.Udp);
     active = true;

     // recv & send are called from main thread.
     // need to ensure this never blocks.
     // even a 1ms block per connection would stop us from scaling.
     socket.Blocking = false;

     // configure buffer sizes
     Common.ConfigureSocketBuffers(socket, config.RecvBufferSize, config.SendBufferSize);

     // bind to endpoint so we can use send/recv instead of sendto/recvfrom.
     socket.Connect(remoteEndPoint);

     // immediately send a hello message to the server.
     // server will call OnMessage and add the new connection.
     // note that this still has cookie=0 until we receive the server's hello.
     SendHello();
 }

当然也可以调用Connect的其他重载

// 	Connect client to a NetworkServer by address. More...
static void 	Connect (string address)
//Connect client to a NetworkServer by Uri. More...
static void 	Connect (Uri uri)
//字如其名
static void 	ConnectHost ()

断开连接