/// <summary>
/// 这是主要的函数：发送一个消息给某个用户(C)
/// 流程：直接向某个用户的外网IP发送消息，如果此前没有联系过
/// 那么此消息将无法发送，发送端等待超时。
/// 超时后，发送端将发送一个请求信息到服务端，要求服务端发送
/// 给客户C一个请求，请求C给本机发送打洞消息
/// 以上流程将重复MAXRETRY次
/// </summary>
/// <param name="toUserName">对方用户名</param>
/// <param name="message">待发送的消息</param>
/// <returns></returns>
private bool SendMessageTo(string toUserName, string message)
{
User toUser = userList.Find(toUserName);
if (toUser == null)
{
return(false);
}
for (int i = 0; i < MAXRETRY; i++)
{
P2PTextMessage workMsg = new P2PTextMessage(message);
byte[] buffer = FormatterHelper.Serialize(workMsg);
client.Send(buffer, buffer.Length, toUser.NetPoint);
// 等待接收线程将标记修改
for (int j = 0; j < 10; j++)
{
if (this.ReceivedACK)
{
this.ReceivedACK = false;
return(true);
}
else
{
Thread.Sleep(300);
}
}
// 没有接收到目标主机的回应，认为目标主机的端口映射没有
// 打开，那么发送请求信息给服务器，要服务器告诉目标主机
// 打开映射端口（UDP打洞）
TranslateMessage transMsg = new TranslateMessage(myName, toUserName);
buffer = FormatterHelper.Serialize(transMsg);
client.Send(buffer, buffer.Length, hostPoint);
// 等待对方先发送信息
Thread.Sleep(100);
}
return(false);
}
private async void Run()
{
byte[] buffer = null;
while (true)
{
byte[] msgBuffer = await server.Receive(remotePoint);
try
{
object msgObj = FormatterHelper.Deserialize(msgBuffer);
Type msgType = msgObj.GetType();
if (msgType == typeof(LoginMessage))
{
// 转换接受的消息
LoginMessage lginMsg = (LoginMessage)msgObj;
Console.WriteLine("{0}: user {1} sign in.", System.DateTime.Now.ToString(), lginMsg.UserName);
// 添加用户到列表
IPEndPoint userEndPoint = new IPEndPoint(remotePoint.Address, remotePoint.Port);
User user = new User(lginMsg.UserName, userEndPoint);
userList.Add(user);
// 发送应答消息
ListUserResponseMessage usersMsg = new ListUserResponseMessage(userList);
buffer = FormatterHelper.Serialize(usersMsg);
server.Send(buffer, buffer.Length, remotePoint);
Console.WriteLine("Send:" + usersMsg);
}
else if (msgType == typeof(LogoutMessage))
{
// 转换接受的消息
LogoutMessage lgoutMsg = (LogoutMessage)msgObj;
Console.WriteLine("{0}: {1} sign out", System.DateTime.Now.ToString(), lgoutMsg.UserName);
// 从列表中删除用户
User lgoutUser = userList.Find(lgoutMsg.UserName);
if (lgoutUser != null)
{
userList.Remove(lgoutUser);
}
}
else if (msgType == typeof(TranslateMessage))
{
// 转换接受的消息
TranslateMessage transMsg = (TranslateMessage)msgObj;
Console.WriteLine("{0}(1) wants to p2p {2}", remotePoint.Address.ToString(), transMsg.UserName, transMsg.ToUserName);
// 获取目标用户
User toUser = userList.Find(transMsg.ToUserName);
// 转发Purch Hole请求消息
if (toUser == null)
{
Console.WriteLine("Remote host {0} cannot be found at index server", transMsg.ToUserName);
}
else
{
PingMessage transMsg2 = new PingMessage(remotePoint);
buffer = FormatterHelper.Serialize(transMsg);
server.Send(buffer, buffer.Length, toUser.NetPoint);
Console.WriteLine("Send:" + transMsg2);
}
}
else if (msgType == typeof(ListUserMessage))
{
// 发送当前用户信息到所有登录客户
ListUserResponseMessage srvResMsg = new ListUserResponseMessage(userList);
buffer = FormatterHelper.Serialize(srvResMsg);
foreach (User user in userList.InnerList)
{
server.Send(buffer, buffer.Length, user.NetPoint);
Console.WriteLine("Send:" + srvResMsg);
}
}
Thread.Sleep(500);
}
catch (Exception e)
{
System.Console.WriteLine(e.Message);
System.Console.WriteLine(e.StackTrace);
}
}
}