“从 SerialPort 输入缓冲区中同步读取一个字节”，“同步”如何理解？

[tianyaxiao]

“从 SerialPort 输入缓冲区中同步读取一个字节”，“同步”如何理解？

[tianyaxiao]

能给个应用举例吗

[nonocast]

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using SMSLibrary;
using System.IO.Ports;
using System.Text.RegularExpressions;
using System.IO;
using System.Threading;
using System.Diagnostics;

namespace SMSImpl {
	public class SMSModem {
		public bool IsOpen { get { return isOpen; } }
		public SMSModem(string portName) {
			this.portName = portName;

			Regex r1 = new Regex(@"^\+CMTI\:");
			Regex r2 = new Regex(@"^\+CMGR\:");
			Regex r3 = new Regex(@"^\+RING\:");

			ATBeginHandlerMap.Add(r1, OnBeginCMTI);
			ATBeginHandlerMap.Add(r2, OnBeginCMGR);
			ATBeginHandlerMap.Add(r3, OnBeginRING);

			ATHandlerMap.Add(r1, OnCMTI);
			ATHandlerMap.Add(r2, OnCMGR);
			ATHandlerMap.Add(r3, OnRING);

			responseMap.Add(typeof(SendSMSRequest), OnCMGSResponse);
		}

		public void Open() {
			port = new SerialPort(portName);
			port.Encoding = Encoding.Default;
			port.ReadTimeout = 30000;
			port.WriteTimeout = 30000;
			port.BaudRate = 9600;
			port.RtsEnable = true;

			port.Open();
			port.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived);

			AddRequestToQueue(new SettingReuqest("AT").Execute(port));
			Thread.Sleep(50);
			AddRequestToQueue(new SettingReuqest("ATE0").Execute(port));
			AddRequestToQueue(new SettingReuqest("AT+CMGF=1").Execute(port));
			AddRequestToQueue(new SettingReuqest("AT+CNMI=2,1").Execute(port));
			AddRequestToQueue(new SettingReuqest("AT+CSMP=49,167,0,8").Execute(port));

			isOpen = true;
		}

		public void Close() {
			port.DataReceived -= port_DataReceived;
			port.Close();
			isOpen = false;
		}

		public void Send(SMS arg) {
			if (arg.Text.Length > 70) {
				throw new Exception("短信超过70个字符！");
			}

			AddRequestToQueue(new SendSMSRequest(arg).Execute(port));
		}

		// ----------------------------------------------------------------------
		private void port_DataReceived(object sender, SerialDataReceivedEventArgs e) {
			string line = string.Empty;

			try {
				while (port.BytesToRead > 0) {
					line = port.ReadLine();
					if (!string.IsNullOrEmpty(line) && "\r" != line) {
						Console.WriteLine(line);
						receiveBuffer.Add(line);

						if (!isInterrupt) {
							if (IsBeginInterrupt(line)) {
								if (IsEndInterrupt()) {
									EndInterrupt();
								}
							} else {
								string c = line.TrimEnd('\r');
								if ("OK" == c || "ERROR" == c) {
									var response = new ModemResponse(receiveBuffer);
									response.Request = requestQueue.Dequeue();
									Type t = response.Request.GetType();
									if (responseMap.ContainsKey(t)) {
										responseMap[t](response);
									}
									receiveBuffer.Clear();
								}
							}
						} else {
							if (IsEndInterrupt()) {
								EndInterrupt();
							}
						}
					}
				}
			} catch (Exception ex) {
				Trace.WriteLine(ex);
			}
		}

		private void EndInterrupt() {
			interruptHandler(receiveBuffer);

			beginInterruptHandler = null;
			interruptHandler = null;
			receiveBuffer.Clear();
		}

		private bool IsEndInterrupt() {
			Trace.Assert(beginInterruptHandler != null);
			bool result = false;
			if (beginInterruptHandler(receiveBuffer)) {
				result = true;
			}
			return result;
		}

		private bool IsBeginInterrupt(string arg) {
			bool result = false;

			foreach (var each in ATBeginHandlerMap.Keys) {
				if (each.IsMatch(arg)) {
					beginInterruptHandler = ATBeginHandlerMap[each];
					interruptHandler = ATHandlerMap[each];
					result = true;
					break;
				}
			}

			return result;
		}

		private bool OnBeginCMTI(List<string> content) {
			return true;
		}

		private void OnCMTI(List<string> content) {
			// +CMTI:"SM",1
			Regex pattern = new Regex(@"^\+CMTI:.+,(\d+)");
			Match m = pattern.Match(content[0]);
			index = Convert.ToInt32(m.Groups[1].Value);

			AddRequestToQueue(new RetrieveSMSReuqest(index).Execute(port));
		}

		private bool OnBeginCMGR(List<string> content) {
			return (content.Count == 3);
		}

		private void OnCMGR(List<string> content) {
			Regex pattern = new Regex("^\\+CMGR:.+,\"(\\S+)\",");

			Match m = pattern.Match(content[0]);
			string address = m.Groups[1].Value;
			if (address.StartsWith("+86")) {
				address = address.Substring(3);
			}
			string content1 = content[1].TrimEnd('\r');
			if (content1.StartsWith("050003")) {
				content1 = content1.Substring(12);
			}

			SMS sms = new SMS(address, SMSHelper.SMSDecode(content1));
			sms.Raw = content[1].TrimEnd('\r');
			sms.Flags = 0;
			sms.CreatedAt = DateTime.Now;

			deleteByIndex(index);
			Receive(sms);
		}

		private bool OnBeginRING(List<string> content) {
			return true;
		}

		private void OnRING(List<string> content) {

		}

		private void OnCMGSResponse(ModemResponse response) {
			SendResult(response);
		}

		private void deleteByIndex(int index) {
			port.Write(string.Format("AT+CMGD={0}\r", index));
		}

		private void AddRequestToQueue(ModemMessage arg) {
			if (arg is ModemRequest) {
				requestQueue.Enqueue(arg as ModemRequest);
			}
		}

		private List<string> receiveBuffer = new List<string>();
		private ATReceivedEventHandler interruptHandler;
		private ATBeginReceivedEventHandler beginInterruptHandler;
		private bool isInterrupt { get { return beginInterruptHandler != null; } }

		private Queue<ModemRequest> requestQueue = new Queue<ModemRequest>();
		private Dictionary<Type, ModemResponseHandler> responseMap = new Dictionary<Type, ModemResponseHandler>();
		private Dictionary<Regex, ATBeginReceivedEventHandler> ATBeginHandlerMap = new Dictionary<Regex, ATBeginReceivedEventHandler>();
		private Dictionary<Regex, ATReceivedEventHandler> ATHandlerMap = new Dictionary<Regex, ATReceivedEventHandler>();
		private string portName;
		private SerialPort port;
		private int index;
		private bool isOpen = false;

		public event SMSReceivedEventHandler Receive;
		public event SMSSendEventHandler SendResult;
	}

	public delegate bool ATBeginReceivedEventHandler(List<string> content);
	public delegate void ATReceivedEventHandler(List<string> content);
	public delegate void ModemResponseHandler(ModemResponse response);
	public delegate void SMSReceivedEventHandler(SMS arg);
	public delegate void SMSSendEventHandler(ModemResponse response);

}

[nonocast]

Send/Receive分离

[nonocast]

就是在当前代码序列中直接返回一个字节，比如
char result = sp.Read();
而异步通知是没有返回值，通过回调(CallBack)来返回内容

一般做SerialPort编程多采用异步结构

[WAN]

没成功取到这一字节前，函数不会返回，所在线程将阻塞