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内存管理和异常处理

network-programming exception-handling memory-management c#

Jamie Keeling · 技术社区 · 14 年前

使多个用户一次与服务器通信,每个新的客户端连接在单独的线程上建立。

在这个类中,我创建两个流作为客户端的入站和出站流。我先创建字段,然后在一个单独的方法中初始化对象,这仅仅是因为该对象在其他几个地方使用。

这意味着我有一个相当烦人的方法,只用于关闭底层连接,而不是更多。

我希望我的解释是正确的,我会发一个片段给你看。

谢谢!

//Fields
        TcpClient tcpClient;

        //The thread that will send information to the client
        private Thread thrSender;
        private StreamReader srReceiver;
        private StreamWriter swSender;
        private string currentUser;
        private string strResponse;

        //The constructor of the class takes in a TCP connection
        public Connection(TcpClient tcpCon)
        {
            tcpClient = tcpCon;

            //The thread that accepts the client and waits messages
            thrSender = new Thread(AcceptClient);

            //The thread calls the AcceptClient method
            thrSender.Start();
        }

        private void CloseConnection()
        {
            //Close the currently open objects
            tcpClient.Close();
            srReceiver.Close();
            swSender.Close();
        }

        //Occurs when a new client is accepted
        private void AcceptClient()
        {
            srReceiver = new StreamReader(tcpClient.GetStream());
            swSender = new StreamWriter(tcpClient.GetStream());

            //Read account information from the client
            currentUser = srReceiver.ReadLine();

            //Examine response from client
            if (currentUser != "")
            {
                //Store the user name in the hash table
                if (ChatServer.htUsers.Contains(currentUser) == true)
                {
                    //0 means not connected - Writes error to Client and Server log
                    swSender.WriteLine("0|This username already exists.");
                    swSender.Flush();
                    CloseConnection();
                    return;
                }
                //More if/else if/else statements
                //...  

        }

    }

1 回复 | 直到 14 年前

Steve 14 年前

您可以在AcceptClient方法中相当容易地处理这两个流,方法是将它们设置为局部变量,因为它们在其他地方没有被引用,如下所示:

private void AcceptClient()
{
    using (StreamReader srReceiver = new StreamReader(tcpClient.GetStream()))
    {
        using (StreamWriter swSender = new StreamWriter(tcpClient.GetStream()))
        {
            // ...
        }
    }
}

private void AcceptClient()
{
    try
    {
        using (StreamReader srReceiver = new StreamReader(tcpClient.GetStream()))
        {
            using (StreamWriter swSender = new StreamWriter(tcpClient.GetStream()))
            {
                // ...
            }
        }
    }
    finally
    {
        tcpClient.Dispose();
    }
}

无论try子句是否抛出异常,都将调用finally子句。