C# UDP 网络聊天程序
学习了UDP协议的使用以及TCP协议的对比,各有各的优势!
个人理解优势区别如下:
1:UDP协议称为不可靠的传输协议,因为在从发送方到接收方的传递过程中出现的数据丢失,协议本身并不能做出任何检测或者提示。
2:UDP速度比TCP快,因为UDP不需要先与对方建立连接,也不需要连接确认,因此速度要快的多。
理解下使用情景:
并不是说一个程序用UDP就用UDP 用TCP就用TCP,比如说QQ聊天,我们要开视频,语音,发送文件,文字。
其中开视频,语音就可以用UDP协议去做,文字也可以用UDP协议去做。而发送文件就用TCP去做啦,因为发送文件比较大的话 中途数据丢失,造成文件的完整性。。也会导致出问题。。而视频,在线电影这些就无所谓了,丢一点点也是看不出来的。
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该程序测试了局域网,外网。
下面也说下连接局域网和外网的方式:
局域网:直接在软件上指向目标机的内网IP地址即可(如:192.168.1.223)
外网:指向目标机的外网IP地址,并且本机与目标机的路由器务必映射端口8889(可自行在源码里更改)
以下是截图与完整代码:
截图:
完整代码:
引入命名空间:
using System.Net; using System.Net.Sockets; using System.Threading;代码:
namespace UdpChatExample { public partial class FormChat : Form { /// <summary>接收用</summary> private UdpClient receiveUdpClient; /// <summary>发送用</summary> private UdpClient sendUdpClient; /// <summary>和本机绑定的端口号</summary> private const int port = 18001; /// <summary>本机IP</summary> IPAddress ip; /// <summary>远程主机IP</summary> IPAddress remoteIp; public FormChat() { InitializeComponent(); //获取本机可用IP地址 IPAddress[] ips = Dns.GetHostAddresses(Dns.GetHostName()); ip = ips[ips.Length - 1]; //为了在同一台机器调试,此IP也作为默认远程IP remoteIp = ip; textBoxRemoteIP.Text = remoteIp.ToString(); textBoxSend.Text = "你好!"; } private void FormChat_Load(object sender, EventArgs e) { //创建一个线程接收远程主机发来的信息 Thread myThread = new Thread(ReceiveData); //将线程设为后台运行 myThread.IsBackground = true; myThread.Start(); textBoxSend.Focus(); } private void ReceiveData() { IPEndPoint local = new IPEndPoint(ip, port); receiveUdpClient = new UdpClient(local); IPEndPoint remote = new IPEndPoint(IPAddress.Any, 0); while (true) { try { //关闭udpClient时此句会产生异常 byte[] receiveBytes = receiveUdpClient.Receive(ref remote); string receiveMessage = Encoding.Unicode.GetString( receiveBytes, 0, receiveBytes.Length); AddItem(listBoxReceive, string.Format("来自{0}:{1}", remote, receiveMessage)); } catch { break; } } } private void buttonSend_Click(object sender, EventArgs e) { Thread t = new Thread(SendMessage); t.IsBackground = true; t.Start(textBoxSend.Text); } /// <summary>发送数据到远程主机</summary> private void SendMessage(object obj) { string message = (string)obj; sendUdpClient = new UdpClient(0); byte[] bytes = System.Text.Encoding.Unicode.GetBytes(message); IPEndPoint iep = new IPEndPoint(remoteIp, port); try { sendUdpClient.Send(bytes, bytes.Length, iep); AddItem(listBoxStatus, string.Format("向{0}发送:{1}", iep, message)); ClearTextBox(); } catch (Exception ex) { AddItem(listBoxStatus, "发送出错:" + ex.Message); } } delegate void AddListBoxItemDelegate(ListBox listbox, string text); private void AddItem(ListBox listbox, string text) { if (listbox.InvokeRequired) { AddListBoxItemDelegate d = AddItem; listbox.Invoke(d, new object[] { listbox, text }); } else { listbox.Items.Add(text); listbox.SelectedIndex = listbox.Items.Count - 1; listbox.ClearSelected(); } } delegate void ClearTextBoxDelegate(); private void ClearTextBox() { if (textBoxSend.InvokeRequired) { ClearTextBoxDelegate d = ClearTextBox; textBoxSend.Invoke(d); } else { textBoxSend.Clear(); textBoxSend.Focus(); } } } }如果编译有问题的朋友,可以到下面地址下载我上传的资源文件,谢谢。