/// <summary>/// 网口通信/// </summary>public interface INetContact : IPortContact{ActionResult Connect(string ip, int port);}public class NetContact : INetContact{Socket _socket = null;private readonly int TryReconnectTimes = 3;private readonly int Timeout = 5000;public bool Opened { get; set; }/// <summary>/// Connects the specified ip.连接网口打印机/// </summary>/// <param name="ip">The ip.</param>/// <param name="port">The port.</param>/// <returns></returns>public ActionResult Connect(string ip, int port){if (string.IsNullOrEmpty(ip)){return new ActionResult(false, "网口打印机未指定有效IP地址");}// 先关闭if (Opened){_socket.Close();Opened = false;}try{for (int i = 0; i < TryReconnectTimes; i++){// 创建socket并连接到服务器_socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);var result = _socket.BeginConnect(IPAddress.Parse(ip), port, null, null);bool success = result.AsyncWaitHandle.WaitOne(Timeout, true);if (success){try{_socket.EndConnect(result);Opened = true;return new ActionResult(true);}catch (SocketException){continue;}}else{_socket.Close();}}return new ActionResult(false, string.Format("打印机IP:{0}连接超时,请检查网络是否存在异常!", ip));}catch (Exception ex){return new ActionResult(false,string.Format("连接网口打印机失败:{0}", ex.Message));}}/// <summary>/// Sends the specified data.发送文本到打印机/// </summary>/// <param name="data">The data.</param>/// <returns></returns>public int Write(string data){return Write(Encoding.GetEncoding("gb2312").GetBytes(data));}/// <summary>/// Sends the specified data.发送byte数据到打印机/// </summary>/// <param name="data">The data.</param>/// <returns></returns>public int Write(byte[] data){if (!Opened){return 0;}int offset = 0;try{int timeout = TimeSpan.FromSeconds(10).Milliseconds;int waitTime = TimeSpan.FromMilliseconds(30).Milliseconds;_socket.SendTimeout = timeout;while (offset != data.Length){if (_socket.Poll(waitTime, SelectMode.SelectWrite)){offset += _socket.Send(data, offset, data.Length - offset, SocketFlags.None);}}}catch (Exception ex){throw new Exception(string.Format("向网口打印机发送数据失败:{0}", ex.Message));}return offset;}/// <summary>/// Closes this connection.关闭网络连接/// </summary>public void Close(){if (Opened){_socket.Shutdown(SocketShutdown.Both);_socket.Close();Opened = false;}_socket = null;}public byte[] Read(int length){byte[] buffer = null;if (Opened){buffer = new byte[length];_socket.Receive(buffer);}return buffer;}}