C# 简单通信（实现文件传输）

https://blog.csdn.net/Sayesan/article/details/82185772

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：

1. using System;

2. using System.Collections.Generic;

3. using System.ComponentModel;

4. using System.Data;

5. using System.Drawing;

6. using System.Linq;

7. using System.Text;

8. using System.Threading.Tasks;

9. using System.Windows.Forms;

10. using System.Net;

11. using System.Net.Sockets;

12. using System.Threading;

13. using System.IO;

14.  

15. namespace EasyChat

16. {

17. public partial class Server : Form

18. {

19. public Server()

20. {

21. InitializeComponent();

22. //关闭对文本框的非法线程操作检查

23. TextBox.CheckForIllegalCrossThreadCalls = false;

24. }

25.  

26. private void Server_Load(object sender, EventArgs e)

27. {

28. textIP.AppendText("127.0.0.1");

29. textPORT.AppendText("5555");

30. }

31.  

32. Thread threadWatch = null;

33. Socket socketWatch = null;

34.  
35.  

36. private void ServerBegin_Click(object sender, EventArgs e)

37. {

38. //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）

39. socketWatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

40. int port = Convert.ToInt32(textPORT.Text.Trim());

41. IPAddress ip = IPAddress.Parse(textIP.Text.Trim());

42. //绑定IP地址和端口号

43. IPEndPoint ipe = new IPEndPoint(ip, port);

44. socketWatch.Bind(ipe);

45. socketWatch.Listen(20);//监听队列长度，20

46. //负责监听的线程

47. threadWatch = new Thread(WatchConnect);

48. //。。。

49. threadWatch.IsBackground = true;

50. threadWatch.Start();

51. Message.AppendText("服务器已经启动，开始监听..."+" ");

52. }

53.  

54. Socket socketConnect = null;

55.  

56. private void WatchConnect()

57. {

58. while (true)

59. {

60. try

61. {

62. socketConnect = socketWatch.Accept();

63. }

64. catch (Exception ex)

65. {

66. Message.AppendText(ex.Message);

67. break;

68. }

69. Message.AppendText("客户端连接成功，可以开始通信..."+" ");

70. //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

71. ParameterizedThreadStart pts = new ParameterizedThreadStart(ServerRec);

72. Thread thr = new Thread(pts);

73. thr.Start(socketConnect);

74. }

75. }

76.  

77. string recStr = null;

78. private void ServerRec(object obj)

79. {

80. Socket socketServer = obj as Socket;

81. long fileLength = 0;

82.  

83. while (true)

84. {

85. int firstRcv = 0;

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

87. try

88. {

89. //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

90. if (socketServer != null) firstRcv = socketServer.Receive(buffer);

91.  

92. if (firstRcv > 0)//大于0，说明有东西传过来

93. {

94. if (buffer[0] == 0)//0对应文字信息

95. {

96. recStr = Encoding.UTF8.GetString(buffer, 1, firstRcv - 1);

97. Message.AppendText("ZXY: " + GetTime() + " " + recStr + " ");

98. }

99.  

100. if (buffer[0] == 1)//1对应文件信息

101. {

102. string filenameSuffix = recStr.Substring(recStr.LastIndexOf("."));

103. SaveFileDialog sfDialog = new SaveFileDialog()

104. {

105. Filter = "(*" + filenameSuffix + ")|*" + filenameSuffix + "",

106. FileName = recStr

107. };

108.  

109. if (sfDialog.ShowDialog(this) == DialogResult.OK)

110. {

111. string savePath = sfDialog.FileName;

112. int rec = 0;

113. long recFileLength = 0;

114. bool firstWrite = true;

115. using (FileStream fs = new FileStream(savePath, FileMode.Create, FileAccess.Write))

116. {

117. while (recFileLength < fileLength)

118. {

119. if (firstWrite)

120. {

121. fs.Write(buffer, 1, firstRcv - 1);

122. fs.Flush();

123. recFileLength += firstRcv - 1;

124. firstWrite = false;

125. }

126. else

127. {

128. rec = socketServer.Receive(buffer);

129. fs.Write(buffer, 0, rec);

130. fs.Flush();

131. recFileLength += rec;

132. }

133. }

134. fs.Close();

135. }

136.  

137. string fName = savePath.Substring(savePath.LastIndexOf("\") + 1);

138. string fPath = savePath.Substring(0, savePath.LastIndexOf("\"));

139. Message.AppendText("ZXY: " + GetTime() + " 你成功接收了文件..." + fName + " 保存路径为：" + fPath + " ");

140. }

141. }

142. if (buffer[0] == 2)//2对应文件名字和长度

143. {

144. string fileNameWithLength = Encoding.UTF8.GetString(buffer, 1, firstRcv - 1);

145. recStr = fileNameWithLength.Split('-').First();

146. fileLength = Convert.ToInt64(fileNameWithLength.Split('-').Last());

147. }

148. }

149. }

150. catch (Exception ex)

151. {

152. Message.AppendText("系统异常..." + ex.Message);

153. break;

154. }

155. }

156. }

157.  

158. private void ServerSend(string SendStr,byte symbol)

159. {

160. //用UTF8能接受文字信息

161. byte[] buffer = Encoding.UTF8.GetBytes(SendStr);

162. //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

163. byte[] newBuffer = new byte[buffer.Length+1];

164. //标识符添加在位置为0的地方

165. newBuffer[0] = symbol;

166. Buffer.BlockCopy(buffer,0,newBuffer,1,buffer.Length);

167. socketConnect.Send(newBuffer);

168. Message.AppendText("PYT: "+ GetTime() + " " + SendStr+" ");

169. }

170.  

171. string filePath = null;

172. string fileName = null;

173.  

174. private void Select_Click(object sender, EventArgs e)

175. {

176. OpenFileDialog ofDialog = new OpenFileDialog();

177. if(ofDialog.ShowDialog(this) == DialogResult.OK)

178. {

179. fileName = ofDialog.SafeFileName;//获取选取文件的文件名

180. File.Text = fileName;//将文件名显示在文本框上

181. filePath = ofDialog.FileName;//获取包含文件名的全路径

182. }

183. }

184.  

185. private void SendFile(string fileFullPath)

186. {

187. if (string.IsNullOrEmpty(fileFullPath))

188. {

189. MessageBox.Show(@"请选择需要发送的文件!");

190. return;

191. }

192.  

193. //发送文件前，将文件名和长度发过去

194. long fileLength = new FileInfo(fileFullPath).Length;

195. string totalMsg = string.Format("{0}-{1}", fileName, fileLength);

196. ServerSend(totalMsg, 2);

197.  

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

199.  

200. using (FileStream fs = new FileStream(fileFullPath, FileMode.Open, FileAccess.Read))

201. {

202. int readLength = 0;

203. bool firstRead = true;

204. long sentFileLength = 0;

205. while ((readLength = fs.Read(buffer, 0, buffer.Length)) > 0 && sentFileLength < fileLength)

206. {

207. sentFileLength += readLength;

208. //第一次发送的字节流上加个前缀1

209. if (firstRead)

210. {

211. byte[] firstBuffer = new byte[readLength + 1];

212. //标记1，代表为文件

213. firstBuffer[0] = 1;

214. Buffer.BlockCopy(buffer, 0, firstBuffer, 1, readLength);

215.  

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

217.  

218. firstRead = false;

219. continue;

220. }

221. socketConnect.Send(buffer, 0, readLength, SocketFlags.None);

222. }

223. fs.Close();

224. }

225. Message.AppendText("SoFlash:" + GetTime() + " 您发送了文件:" + fileName + " ");

226. }

227.  

228. private void Send_Click(object sender, EventArgs e)

229. {

230. ServerSend(SendMsg.Text,0);

231. }

232.  

233. private void SendMsg_keyDown(object sender, KeyEventArgs e)//Enter发送

234. {

235. if (e.KeyCode == Keys.Enter)

236. {

237. ServerSend(SendMsg.Text,0);

238. }

239. }

240.  

241. private void Sendfile_Click(object sender, EventArgs e)

242. {

243. SendFile(filePath);

244. }

245.  

246. public DateTime GetTime()//获取系统时间

247. {

248. DateTime now = new DateTime();

249. now = DateTime.Now;

250. return now;

251. }

252.  

253. }

254. }

客户端：

1. using System;

2. using System.Collections.Generic;

3. using System.ComponentModel;

4. using System.Data;

5. using System.Drawing;

6. using System.Linq;

7. using System.Text;

8. using System.Threading.Tasks;

9. using System.Windows.Forms;

10. using System.Net;

11. using System.Net.Sockets;

12. using System.Threading;

13. using System.IO;

14.  

15. namespace EasyChats

16. {

17. public partial class Client : Form

18. {

19. public Client()

20. {

21. InitializeComponent();

22. TextBox.CheckForIllegalCrossThreadCalls = false;

23. }

24.  

25. private void Client_Load(object sender, EventArgs e)

26. {

27. textIP.AppendText("127.0.0.1");

28. textPort.AppendText("5555");

29. }

30.  

31. Socket socketClient = null;

32. Thread threadClient = null;

33.  

34. private void BeginClient_Click(object sender, EventArgs e)

35. {

36. socketClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

37. int port = Convert.ToInt32(textPort.Text.Trim());

38. IPAddress ip = IPAddress.Parse(textIP.Text.Trim());

39. IPEndPoint ipe = new IPEndPoint(ip, port);

40. socketClient.Connect(ipe);

41. threadClient = new Thread(RecMsg);

42. threadClient.IsBackground = true;

43. threadClient.Start();

44. Message.AppendText("已经与服务端建立连接，可以开始通信... ");

45. }

46.  

47. private void RecMsg()

48. {

49. long fileLength = 0;

50. string recStr = null;

51. while (true)

52. {

53. int firstRcv = 0;

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

55. try

56. {

57. if (socketClient != null) firstRcv = socketClient.Receive(buffer);

58.  

59. if (firstRcv > 0)

60. {

61. if (buffer[0] == 0)

62. {

63. recStr = Encoding.UTF8.GetString(buffer, 1, firstRcv - 1);

64. Message.AppendText("PYT: " + GetTime() + " " + recStr + " ");

65. }

66.  

67. if (buffer[0] == 1)

68. {

69. string filenameSuffix = recStr.Substring(recStr.LastIndexOf("."));

70. SaveFileDialog sfDialog = new SaveFileDialog()

71. {

72. Filter = "(*" + filenameSuffix + ")|*" + filenameSuffix + "",

73. FileName = recStr

74. };

75.  

76. if (sfDialog.ShowDialog(this) == DialogResult.OK)

77. {

78. string savePath = sfDialog.FileName;

79. int rec = 0;

80. long recFileLength = 0;

81. bool firstWrite = true;

82. using (FileStream fs = new FileStream(savePath, FileMode.Create, FileAccess.Write))

83. {

84. while (recFileLength < fileLength)

85. {

86. if (firstWrite)

87. {

88. fs.Write(buffer, 1, firstRcv - 1);

89. fs.Flush();

90. recFileLength += firstRcv - 1;

91. firstWrite = false;

92. }

93. else

94. {

95. rec = socketClient.Receive(buffer);

96. fs.Write(buffer, 0, rec);

97. fs.Flush();

98. recFileLength += rec;

99. }

100. }

101. fs.Close();

102. }

103.  

104. string fName = savePath.Substring(savePath.LastIndexOf("\") + 1);

105. string fPath = savePath.Substring(0, savePath.LastIndexOf("\"));

106. Message.AppendText("ZXY: " + GetTime() + " 你成功接收了文件..." + fName + " 保存路径为：" + fPath + " ");

107. }

108. }

109. if (buffer[0] == 2)

110. {

111. string fileNameWithLength = Encoding.UTF8.GetString(buffer, 1, firstRcv - 1);

112. recStr = fileNameWithLength.Split('-').First();

113. fileLength = Convert.ToInt64(fileNameWithLength.Split('-').Last());

114. }

115. }

116. }

117. catch (Exception ex)

118. {

119. Message.AppendText("系统异常..." + ex.Message);

120. break;

121. }

122. }

123. }

124.  
125.  

126. private void ClientSend(string SendStr, byte symbol)

127. {

128. byte[] buffer = Encoding.UTF8.GetBytes(SendStr);

129. byte[] newBuffer = new byte[buffer.Length + 1];

130. newBuffer[0] = symbol;

131. Buffer.BlockCopy(buffer, 0, newBuffer, 1, buffer.Length);

132. socketClient.Send(newBuffer);

133. Message.AppendText("ZXY: " + GetTime() + " " + SendStr + " ");

134. }

135.  

136. private void Send_Click_1(object sender, EventArgs e)

137. {

138. ClientSend(SendMsg.Text, 0);

139. }

140.  

141. string filePath = null;

142. string fileName = null;

143.  

144. private void fileSelect_Click(object sender, EventArgs e)

145. {

146. OpenFileDialog ofDialog = new OpenFileDialog();

147. if (ofDialog.ShowDialog(this) == DialogResult.OK)

148. {

149. fileName = ofDialog.SafeFileName;

150. FileName.Text = fileName;

151. filePath = ofDialog.FileName;

152. }

153. }

154.  

155. private void fileSend_Click(object sender, EventArgs e)

156. {

157. SendFile(filePath);

158. }

159.  

160. private void SendFile(string fileFullPath)

161. {

162. if (string.IsNullOrEmpty(fileFullPath))

163. {

164. MessageBox.Show(@"请选择需要发送的文件...");

165. return;

166. }

167.  

168. long fileLength = new FileInfo(fileFullPath).Length;

169. string totalMsg = string.Format("{0}-{1}", fileName, fileLength);

170. ClientSend(totalMsg, 2);

171.  

172. byte[] buffer = new byte[2 * 1024];

173. using (FileStream fs = new FileStream(fileFullPath, FileMode.Open, FileAccess.Read))

174. {

175. int readLength = 0;

176. bool firstRead = true;

177. long sentFileLength = 0;

178. while ((readLength = fs.Read(buffer, 0, buffer.Length)) > 0 && sentFileLength < fileLength)

179. {

180. sentFileLength += readLength;

181. if (firstRead)

182. {

183. byte[] firstBuffer = new byte[readLength + 1];

184. firstBuffer[0] = 1;

185. Buffer.BlockCopy(buffer, 0, firstBuffer, 1, readLength);

186.  

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

188.  

189. firstRead = false;

190. }

191. else

192. {

193. socketClient.Send(buffer, 0, readLength, SocketFlags.None);

194. }

195. }

196. fs.Close();

197. }

198. Message.AppendText("ZXY:" + GetTime() + " 你发送了文件：" + fileName + " ");

199. }

200.  

201. private void Send_Click(object sender, EventArgs e)

202. {

203. ClientSend(SendMsg.Text, 0);

204. }

205.  
206.  
207.  

208. private void SendMsg_keyDown(object sender, KeyEventArgs e)

209. {

210. if (e.KeyCode == Keys.Enter)

211. {

212. ClientSend(SendMsg.Text, 0);

213. }

214. }

215.  

216. private void Sendfile_Click(object sender, EventArgs e)

217. {

218. SendFile(filePath);

219. }

220.  

221. public DateTime GetTime()

222. {

223. DateTime now = new DateTime();

224. now = DateTime.Now;

225. return now;

226. }

227.  
228.  

229. }

230. }

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。