本文介绍在C#中如何利用TcpClient与TcpListener进行简单的消息发送和接收。在使用时要注意，如果是本机发送与接收，发送消息时IP用127.0.0.1，如果是非本机接收，请在接收端打开相应的端口（本例中为13）。
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading.Tasks;
//接收方
public Form1(){
InitializeComponent();
Task.Factory.StartNew(() =>
{
TcpListener listener = null;
TcpClient client = null;
string message = string.Empty;
while (true) //循环接收消息，否则只能接收一次
{
try
{
listener = new TcpListener(IPAddress.Any, 13);
listener.Start();
client = listener.AcceptTcpClient();
using (StreamReader sr = new StreamReader(client.GetStream()))
{
message = sr.ReadToEnd();
}
}
catch
{
message = "error";
}
finally
{
client.Close();
listener.Stop();
}
MessageBox.Show(message);
}
});
}
//发送方
public void SendMessage(string receiverHostIP, int port, string message)
{
TcpClient client = null;
try
{
client = new TcpClient();
client.Connect(receiverHostIP, port);
using (NetworkStream ns = client.GetStream())
{
if (ns.CanWrite)
{
byte[] send = System.Text.Encoding.UTF8.GetBytes(message); //如果不使用UTF8编码，则无法处理中文
ns.Write(send, 0, send.Length);
}
else
{
//cannot send message
MessageBox.Show("cannot send message");
ns.Dispose();
}
}
}
catch
{
}
finally
{
client.Close();
}
}
private void button1_Click(object sender, EventArgs e)
{
this.SendMessage("127.0.0.1", 13, "要发送的消息");
}