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. namespace EasyChat

15. {

16. public partial class Server : Form

17. {

18. public Server()

19. {

20. InitializeComponent();

21. //关闭对文本框的非法线程操作检查

22. TextBox.CheckForIllegalCrossThreadCalls = false;

23. }

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

25. {

26. textIP.AppendText("127.0.0.1");

27. textPORT.AppendText("5555");

28. }

29. Thread threadWatch = null;

30. Socket socketWatch = null;

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

32. {

33. //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）

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

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

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

37. //绑定IP地址和端口号

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

39. socketWatch.Bind(ipe);

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

41. //负责监听的线程

42. threadWatch = new Thread(WatchConnect);

43. //。。。

44. threadWatch.IsBackground = true;

45. threadWatch.Start();

46. Message.AppendText("服务器已经启动，开始监听..."+"\r\n");

47. }

48. Socket socketConnect = null;

49. private void WatchConnect()

50. {

51. while (true)

52. {

53. try

54. {

55. socketConnect = socketWatch.Accept();

56. }

57. catch (Exception ex)

58. {

59. Message.AppendText(ex.Message);

60. break;

61. }

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

63. //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

64. ParameterizedThreadStart pts = new ParameterizedThreadStart(ServerRec);

65. Thread thr = new Thread(pts);

66. thr.Start(socketConnect);

67. }

68. }

69. string recStr = null;

70. private void ServerRec(object obj)

71. {

72. Socket socketServer = obj as Socket;

73. long fileLength = 0;

74. while (true)

75. {

76. int firstRcv = 0;

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

78. try

79. {

80. //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

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

82. if (firstRcv > 0)//大于0，说明有东西传过来

83. {

84. if (buffer[0] == 0)//0对应文字信息

85. {

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

87. Message.AppendText("ZXY: " + GetTime() + "\r\n" + recStr + "\r\n");

88. }

89. if (buffer[0] == 1)//1对应文件信息

90. {

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

92. SaveFileDialog sfDialog = new SaveFileDialog()

93. {

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

95. FileName = recStr

96. };

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

98. {

99. string savePath = sfDialog.FileName;

100. int rec = 0;

101. long recFileLength = 0;

102. bool firstWrite = true;

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

104. {

105. while (recFileLength < fileLength)

106. {

107. if (firstWrite)

108. {

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

110. fs.Flush();

111. recFileLength += firstRcv - 1;

112. firstWrite = false;

113. }

114. else

115. {

116. rec = socketServer.Receive(buffer);

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

118. fs.Flush();

119. recFileLength += rec;

120. }

121. }

122. fs.Close();

123. }

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

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

126. 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");

127. }

128. }

129. if (buffer[0] == 2)//2对应文件名字和长度

130. {

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

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

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

134. }

135. }

136. }

137. catch (Exception ex)

138. {

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

140. break;

141. }

142. }

143. }

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

145. {

146. //用UTF8能接受文字信息

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

148. //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

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

150. //标识符添加在位置为0的地方

151. newBuffer[0] = symbol;

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

153. socketConnect.Send(newBuffer);

154. Message.AppendText("PYT: "+ GetTime() + "\r\n" + SendStr+"\r\n");

155. }

156. string filePath = null;

157. string fileName = null;

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

159. {

160. OpenFileDialog ofDialog = new OpenFileDialog();

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

162. {

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

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

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

166. }

167. }

168. private void SendFile(string fileFullPath)

169. {

170. if (string.IsNullOrEmpty(fileFullPath))

171. {

172. MessageBox.Show(@"请选择需要发送的文件!");

173. return;

174. }

175. //发送文件前，将文件名和长度发过去

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

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

178. ServerSend(totalMsg, 2);

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

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

181. {

182. int readLength = 0;

183. bool firstRead = true;

184. long sentFileLength = 0;

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

186. {

187. sentFileLength += readLength;

188. //第一次发送的字节流上加个前缀1

189. if (firstRead)

190. {

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

192. //标记1，代表为文件

193. firstBuffer[0] = 1;

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

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

196. firstRead = false;

197. continue;

198. }

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

200. }

201. fs.Close();

202. }

203. Message.AppendText("SoFlash:" + GetTime() + "\r\n您发送了文件:" + fileName + "\r\n");

204. }

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

206. {

207. ServerSend(SendMsg.Text,0);

208. }

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

210. {

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

212. {

213. ServerSend(SendMsg.Text,0);

214. }

215. }

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

217. {

218. SendFile(filePath);

219. }

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

221. {

222. DateTime now = new DateTime();

223. now = DateTime.Now;

224. return now;

225. }

226. }

227. }

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. namespace EasyChats

15. {

16. public partial class Client : Form

17. {

18. public Client()

19. {

20. InitializeComponent();

21. TextBox.CheckForIllegalCrossThreadCalls = false;

22. }

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

24. {

25. textIP.AppendText("127.0.0.1");

26. textPort.AppendText("5555");

27. }

28. Socket socketClient = null;

29. Thread threadClient = null;

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

31. {

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

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

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

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

36. socketClient.Connect(ipe);

37. threadClient = new Thread(RecMsg);

38. threadClient.IsBackground = true;

39. threadClient.Start();

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

41. }

42. private void RecMsg()

43. {

44. long fileLength = 0;

45. string recStr = null;

46. while (true)

47. {

48. int firstRcv = 0;

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

50. try

51. {

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

53. if (firstRcv > 0)

54. {

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

56. {

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

58. Message.AppendText("PYT: " + GetTime() + "\r\n" + recStr + "\r\n");

59. }

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

61. {

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

63. SaveFileDialog sfDialog = new SaveFileDialog()

64. {

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

66. FileName = recStr

67. };

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

69. {

70. string savePath = sfDialog.FileName;

71. int rec = 0;

72. long recFileLength = 0;

73. bool firstWrite = true;

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

75. {

76. while (recFileLength < fileLength)

77. {

78. if (firstWrite)

79. {

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

81. fs.Flush();

82. recFileLength += firstRcv - 1;

83. firstWrite = false;

84. }

85. else

86. {

87. rec = socketClient.Receive(buffer);

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

89. fs.Flush();

90. recFileLength += rec;

91. }

92. }

93. fs.Close();

94. }

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

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

97. 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");

98. }

99. }

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

101. {

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

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

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

105. }

106. }

107. }

108. catch (Exception ex)

109. {

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

111. break;

112. }

113. }

114. }

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

116. {

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

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

119. newBuffer[0] = symbol;

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

121. socketClient.Send(newBuffer);

122. Message.AppendText("ZXY: " + GetTime() + "\r\n" + SendStr + "\r\n");

123. }

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

125. {

126. ClientSend(SendMsg.Text, 0);

127. }

128. string filePath = null;

129. string fileName = null;

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

131. {

132. OpenFileDialog ofDialog = new OpenFileDialog();

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

134. {

135. fileName = ofDialog.SafeFileName;

136. FileName.Text = fileName;

137. filePath = ofDialog.FileName;

138. }

139. }

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

141. {

142. SendFile(filePath);

143. }

144. private void SendFile(string fileFullPath)

145. {

146. if (string.IsNullOrEmpty(fileFullPath))

147. {

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

149. return;

150. }

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

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

153. ClientSend(totalMsg, 2);

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

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

156. {

157. int readLength = 0;

158. bool firstRead = true;

159. long sentFileLength = 0;

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

161. {

162. sentFileLength += readLength;

163. if (firstRead)

164. {

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

166. firstBuffer[0] = 1;

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

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

169. firstRead = false;

170. }

171. else

172. {

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

174. }

175. }

176. fs.Close();

177. }

178. Message.AppendText("ZXY:" + GetTime() + "\r\n你发送了文件：" + fileName + "\r\n");

179. }

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

181. {

182. ClientSend(SendMsg.Text, 0);

183. }

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

185. {

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

187. {

188. ClientSend(SendMsg.Text, 0);

189. }

190. }

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

192. {

193. SendFile(filePath);

194. }

195. public DateTime GetTime()

196. {

197. DateTime now = new DateTime();

198. now = DateTime.Now;

199. return now;

200. }

201. }

202. }

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。