C# 简单通信（实现文件传输）

之前写过一个简单通信传输，不过只有聊天的功能，现在实现了文件传输的功能，借鉴于网上一篇博客，不过他写的仅仅是客户端对于服务器发送文件，我稍微优化了这个功能，实现了，端与端之间信息的互发和文件的互发，感觉学习这些新的东西，还刚开始，进度很慢，很多东西都需要从新去学习，不过慢慢来！Fighting！！！

服务器：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.IO;

namespace EasyChat
{
public partial class Server : Form
{
public Server()
{
InitializeComponent();
//关闭对文本框的非法线程操作检查
TextBox.CheckForIllegalCrossThreadCalls = false;
}

private void Server_Load(object sender, EventArgs e)
{
textIP.AppendText("127.0.0.1");
textPORT.AppendText("5555");
}

Thread threadWatch = null;
Socket socketWatch = null;

private void ServerBegin_Click(object sender, EventArgs e)
{
//定义一个套接字，监听发来的信息，包含3个参数（IP4寻址协议，流式连接，TCP协议）
socketWatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
int port = Convert.ToInt32(textPORT.Text.Trim());
IPAddress ip = IPAddress.Parse(textIP.Text.Trim());
//绑定IP地址和端口号
IPEndPoint ipe = new IPEndPoint(ip, port);
socketWatch.Bind(ipe);
socketWatch.Listen(20);//监听队列长度，20
//负责监听的线程
threadWatch = new Thread(WatchConnect);
//。。。
threadWatch.IsBackground = true;
threadWatch.Start();
Message.AppendText("服务器已经启动，开始监听..."+"\r\n");
}

Socket socketConnect = null;

private void WatchConnect()
{
while (true)
{
try
{
socketConnect = socketWatch.Accept();
}
catch (Exception ex)
{
Message.AppendText(ex.Message);
break;
}
Message.AppendText("客户端连接成功，可以开始通信..."+"\r\n");
//创建通信线程，感觉这个和Thread的区别，就是这个有参，另一个无参
ParameterizedThreadStart pts = new ParameterizedThreadStart(ServerRec);
Thread thr = new Thread(pts);
thr.Start(socketConnect);
}
}

string recStr = null;
private void ServerRec(object obj)
{
Socket socketServer = obj as Socket;
long fileLength = 0;

while (true)
{
int firstRcv = 0;
byte[] buffer = new byte[8 * 1024];
try
{
//获取接受数据的长度，存入内存缓冲区，返回一个字节数组的长度
if (socketServer != null) firstRcv = socketServer.Receive(buffer);

if (firstRcv > 0)//大于0，说明有东西传过来
{
if (buffer[0] == 0)//0对应文字信息
{
recStr = Encoding.UTF8.GetString(buffer, 1, firstRcv - 1);
Message.AppendText("ZXY: " + GetTime() + "\r\n" + recStr + "\r\n");
}

if (buffer[0] == 1)//1对应文件信息
{
string filenameSuffix = recStr.Substring(recStr.LastIndexOf("."));
SaveFileDialog sfDialog = new SaveFileDialog()
{
Filter = "(*" + filenameSuffix + ")|*" + filenameSuffix + "",
FileName = recStr
};

if (sfDialog.ShowDialog(this) == DialogResult.OK)
{
string savePath = sfDialog.FileName;
int rec = 0;
long recFileLength = 0;
bool firstWrite = true;
using (FileStream fs = new FileStream(savePath, FileMode.Create, FileAccess.Write))
{
while (recFileLength < fileLength)
{
if (firstWrite)
{
fs.Write(buffer, 1, firstRcv - 1);
fs.Flush();
recFileLength += firstRcv - 1;
firstWrite = false;
}
else
{
rec = socketServer.Receive(buffer);
fs.Write(buffer, 0, rec);
fs.Flush();
recFileLength += rec;
}
}
fs.Close();
}

string fName = savePath.Substring(savePath.LastIndexOf("\\") + 1);
string fPath = savePath.Substring(0, savePath.LastIndexOf("\\"));
Message.AppendText("ZXY: " + GetTime() + "\r\n你成功接收了文件..." + fName + "\r\n保存路径为：" + fPath + "\r\n");
}
}
if (buffer[0] == 2)//2对应文件名字和长度
{
string fileNameWithLength = Encoding.UTF8.GetString(buffer, 1, firstRcv - 1);
recStr = fileNameWithLength.Split('-').First();
fileLength = Convert.ToInt64(fileNameWithLength.Split('-').Last());
}
}
}
catch (Exception ex)
{
Message.AppendText("系统异常..." + ex.Message);
break;
}
}
}

private void ServerSend(string SendStr,byte symbol)
{
//用UTF8能接受文字信息
byte[] buffer = Encoding.UTF8.GetBytes(SendStr);
//实际发送的字节数组比实际输入的长度多1，用于存取标识符
byte[] newBuffer = new byte[buffer.Length+1];
//标识符添加在位置为0的地方
newBuffer[0] = symbol;
Buffer.BlockCopy(buffer,0,newBuffer,1,buffer.Length);
socketConnect.Send(newBuffer);
Message.AppendText("PYT: "+ GetTime() + "\r\n" + SendStr+"\r\n");
}

string filePath = null;
string fileName = null;

private void Select_Click(object sender, EventArgs e)
{
OpenFileDialog ofDialog = new OpenFileDialog();
if(ofDialog.ShowDialog(this) == DialogResult.OK)
{
fileName = ofDialog.SafeFileName;//获取选取文件的文件名
File.Text = fileName;//将文件名显示在文本框上
filePath = ofDialog.FileName;//获取包含文件名的全路径
}
}

private void SendFile(string fileFullPath)
{
if (string.IsNullOrEmpty(fileFullPath))
{
MessageBox.Show(@"请选择需要发送的文件!");
return;
}

//发送文件前，将文件名和长度发过去
long fileLength = new FileInfo(fileFullPath).Length;
string totalMsg = string.Format("{0}-{1}", fileName, fileLength);
ServerSend(totalMsg, 2);

byte[] buffer = new byte[8*1024];

using (FileStream fs = new FileStream(fileFullPath, FileMode.Open, FileAccess.Read))
{
int readLength = 0;
bool firstRead = true;
long sentFileLength = 0;
while ((readLength = fs.Read(buffer, 0, buffer.Length)) > 0 && sentFileLength < fileLength)
{
sentFileLength += readLength;
//第一次发送的字节流上加个前缀1
if (firstRead)
{
byte[] firstBuffer = new byte[readLength + 1];
//标记1，代表为文件
firstBuffer[0] = 1;
Buffer.BlockCopy(buffer, 0, firstBuffer, 1, readLength);

socketConnect.Send(firstBuffer, 0, readLength + 1, SocketFlags.None);

firstRead = false;
continue;
}
socketConnect.Send(buffer, 0, readLength, SocketFlags.None);
}
fs.Close();
}
Message.AppendText("SoFlash:" + GetTime() + "\r\n您发送了文件
c415
:" + fileName + "\r\n");
}

private void Send_Click(object sender, EventArgs e)
{
ServerSend(SendMsg.Text,0);
}

private void SendMsg_keyDown(object sender, KeyEventArgs e)//Enter发送
{
if (e.KeyCode == Keys.Enter)
{
ServerSend(SendMsg.Text,0);
}
}

private void Sendfile_Click(object sender, EventArgs e)
{
SendFile(filePath);
}

public DateTime GetTime()//获取系统时间
{
DateTime now = new DateTime();
now = DateTime.Now;
return now;
}

}
}

客户端：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.IO;

namespace EasyChats
{
public partial class Client : Form
{
public Client()
{
InitializeComponent();
TextBox.CheckForIllegalCrossThreadCalls = false;
}

private void Client_Load(object sender, EventArgs e)
{
textIP.AppendText("127.0.0.1");
textPort.AppendText("5555");
}

Socket socketClient = null;
Thread threadClient = null;

private void BeginClient_Click(object sender, EventArgs e)
{
socketClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
int port = Convert.ToInt32(textPort.Text.Trim());
IPAddress ip = IPAddress.Parse(textIP.Text.Trim());
IPEndPoint ipe = new IPEndPoint(ip, port);
socketClient.Connect(ipe);
threadClient = new Thread(RecMsg);
threadClient.IsBackground = true;
threadClient.Start();
Message.AppendText("已经与服务端建立连接，可以开始通信...\r\n");
}

private void RecMsg()
{
long fileLength = 0;
string recStr = null;
while (true)
{
int firstRcv = 0;
byte[] buffer = new byte[8 * 1024];
try
{
if (socketClient != null) firstRcv = socketClient.Receive(buffer);

if (firstRcv > 0)
{
if (buffer[0] == 0)
{
recStr = Encoding.UTF8.GetString(buffer, 1, firstRcv - 1);
Message.AppendText("PYT: " + GetTime() + "\r\n" + recStr + "\r\n");
}

if (buffer[0] == 1)
{
string filenameSuffix = recStr.Substring(recStr.LastIndexOf("."));
SaveFileDialog sfDialog = new SaveFileDialog()
{
Filter = "(*" + filenameSuffix + ")|*" + filenameSuffix + "",
FileName = recStr
};

if (sfDialog.ShowDialog(this) == DialogResult.OK)
{
string savePath = sfDialog.FileName;
int rec = 0;
long recFileLength = 0;
bool firstWrite = true;
using (FileStream fs = new FileStream(savePath, FileMode.Create, FileAccess.Write))
{
while (recFileLength < fileLength)
{
if (firstWrite)
{
fs.Write(buffer, 1, firstRcv - 1);
fs.Flush();
recFileLength += firstRcv - 1;
firstWrite = false;
}
else
{
rec = socketClient.Receive(buffer);
fs.Write(buffer, 0, rec);
fs.Flush();
recFileLength += rec;
}
}
fs.Close();
}

string fName = savePath.Substring(savePath.LastIndexOf("\\") + 1);
string fPath = savePath.Substring(0, savePath.LastIndexOf("\\"));
Message.AppendText("ZXY: " + GetTime() + "\r\n你成功接收了文件..." + fName + "\r\n保存路径为：" + fPath + "\r\n");
}
}
if (buffer[0] == 2)
{
string fileNameWithLength = Encoding.UTF8.GetString(buffer, 1, firstRcv - 1);
recStr = fileNameWithLength.Split('-').First();
fileLength = Convert.ToInt64(fileNameWithLength.Split('-').Last());
}
}
}
catch (Exception ex)
{
Message.AppendText("系统异常..." + ex.Message);
break;
}
}
}

private void ClientSend(string SendStr, byte symbol)
{
byte[] buffer = Encoding.UTF8.GetBytes(SendStr);
byte[] newBuffer = new byte[buffer.Length + 1];
newBuffer[0] = symbol;
Buffer.BlockCopy(buffer, 0, newBuffer, 1, buffer.Length);
socketClient.Send(newBuffer);
Message.AppendText("ZXY: " + GetTime() + "\r\n" + SendStr + "\r\n");
}

private void Send_Click_1(object sender, EventArgs e)
{
ClientSend(SendMsg.Text, 0);
}

string filePath = null;
string fileName = null;

private void fileSelect_Click(object sender, EventArgs e)
{
OpenFileDialog ofDialog = new OpenFileDialog();
if (ofDialog.ShowDialog(this) == DialogResult.OK)
{
fileName = ofDialog.SafeFileName;
FileName.Text = fileName;
filePath = ofDialog.FileName;
}
}

private void fileSend_Click(object sender, EventArgs e)
{
SendFile(filePath);
}

private void SendFile(string fileFullPath)
{
if (string.IsNullOrEmpty(fileFullPath))
{
MessageBox.Show(@"请选择需要发送的文件...");
return;
}

long fileLength = new FileInfo(fileFullPath).Length;
string totalMsg = string.Format("{0}-{1}", fileName, fileLength);
ClientSend(totalMsg, 2);

byte[] buffer = new byte[2 * 1024];
using (FileStream fs = new FileStream(fileFullPath, FileMode.Open, FileAccess.Read))
{
int readLength = 0;
bool firstRead = true;
long sentFileLength = 0;
while ((readLength = fs.Read(buffer, 0, buffer.Length)) > 0 && sentFileLength < fileLength)
{
sentFileLength += readLength;
if (firstRead)
{
byte[] firstBuffer = new byte[readLength + 1];
firstBuffer[0] = 1;
Buffer.BlockCopy(buffer, 0, firstBuffer, 1, readLength);

socketClient.Send(firstBuffer, 0, readLength + 1, SocketFlags.None);

firstRead = false;
}
else
{
socketClient.Send(buffer, 0, readLength, SocketFlags.None);
}
}
fs.Close();
}
Message.AppendText("ZXY:" + GetTime() + "\r\n你发送了文件：" + fileName + "\r\n");
}

private void Send_Click(object sender, EventArgs e)
{
ClientSend(SendMsg.Text, 0);
}

private void SendMsg_keyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
ClientSend(SendMsg.Text, 0);
}
}

private void Sendfile_Click(object sender, EventArgs e)
{
SendFile(filePath);
}

public DateTime GetTime()
{
DateTime now = new DateTime();
now = DateTime.Now;
return now;
}

}
}

对于线程的IsBackground的理解，摘自于网络：

1、当在主线程中创建了一个线程，那么该线程的IsBackground默认是设置为FALSE的。

2、当主线程退出的时候，IsBackground=FALSE的线程还会继续执行下去，直到线程执行结束。

3、只有IsBackground=TRUE的线程才会随着主线程的退出而退出。

4、当初始化一个线程，把Thread.IsBackground=true的时候，指示该线程为后台线程。后台线程将会随着主线程的退出而退出。

5、原理：只要所有前台线程都终止后，CLR就会对每一个活在的后台线程调用Abort（）来彻底终止应用程序。