GJM : Socket TCP 通信连接（二）
上一篇中，我们编写了客户端功能。
这一篇将讲解ISocketHandler的实现。
再来回顾一下ISocketHandler接口。
public interface ISocketHandler
{
/// <summary>
/// 开始接收
/// </summary>
/// <param name="stream">Socket网络流</param>
/// <param name="callback">回调函数</param>
/// <param name="state">自定义状态</param>
/// <returns>异步结果</returns>
IAsyncResult BeginReceive(Stream stream, AsyncCallback callback, object state);
/// <summary>
/// 结束接收
/// </summary>
/// <param name="asyncResult">异步结果</param>
/// <returns>接收到的数据</returns>
byte[] EndReceive(IAsyncResult asyncResult);
/// <summary>
/// 开始发送
/// </summary>
/// <param name="data">要发送的数据</param>
/// <param name="offset">数据偏移</param>
/// <param name="count">发送长度</param>
/// <param name="stream">Socket网络流</param>
/// <param name="callback">回调函数</param>
/// <param name="state">自定义状态</param>
/// <returns>异步结果</returns>
IAsyncResult BeginSend(byte[] data, int offset, int count, Stream stream, AsyncCallback callback, object state);
/// <summary>
/// 结束发送
/// </summary>
/// <param name="asyncResult">异步结果</param>
/// <returns>发送是否成功</returns>
bool EndSend(IAsyncResult asyncResult);
}
做一个类SocketHandler继承ISocketHandler接口
/// <summary>
/// Socket处理程序
/// </summary>
public class SocketHandler : ISocketHandler
{
/// <summary>
/// 开始接收
/// </summary>
/// <param name="stream">Socket网络流</param>
/// <param name="callback">回调函数</param>
/// <param name="state">自定义状态</param>
/// <returns>异步结果</returns>
public IAsyncResult BeginReceive(Stream stream, AsyncCallback callback, object state)
{
}
/// <summary>
/// 结束接收
/// </summary>
/// <param name="asyncResult">异步结果</param>
/// <returns>接收到的数据</returns>
public byte[] EndReceive(IAsyncResult asyncResult)
{
}
/// <summary>
/// 开始发送
/// </summary>
/// <param name="data">要发送的数据</param>
/// <param name="offset">数据偏移</param>
/// <param name="count">发送长度</param>
/// <param name="stream">Socket网络流</param>
/// <param name="callback">回调函数</param>
/// <param name="state">自定义状态</param>
/// <returns>异步结果</returns>
public IAsyncResult BeginSend(byte[] data, int offset, int count, Stream stream, AsyncCallback callback, object state)
{
}
/// <summary>
/// 结束发送
/// </summary>
/// <param name="asyncResult">异步结果</param>
/// <returns>发送是否成功</returns>
public bool EndSend(IAsyncResult asyncResult)
{
}
}
增加两个属性与构造函数。
//异步处理关系集合
private Dictionary<IAsyncResult, SocketHandlerState> StateSet;
//发送队列
private List<SocketHandlerState> SendQueue;
/// <summary>
/// 实例化Socket处理程序
/// </summary>
public SocketHandler()
{
StateSet = new Dictionary<IAsyncResult, SocketHandlerState>();
SendQueue = new List<SocketHandlerState>();
}
StateSet可以保存我们的异步调用结果等数据
SendQueue用来做一个发送队列
接下来我们从发送数据开始。
由于需要用到Stream的异步方法，我们需要定义一个State类。
internal class SocketHandlerState
{
/// <summary>
/// 数据
/// </summary>
public byte[] Data { get; set; }
/// <summary>
/// 异步结果
/// </summary>
public IAsyncResult AsyncResult { get; set; }
/// <summary>
/// Socket网络流
/// </summary>
public Stream Stream { get; set; }
/// <summary>
/// 异步回调函数
/// </summary>
public AsyncCallback AsyncCallBack { get; set; }
/// <summary>
/// 是否完成
/// </summary>
public bool Completed { get; set; }
/// <summary>
/// 数据长度
/// </summary>
public int DataLength { get; set; }
}
因为我们需要返回IAsyncResult，所以我们继承该接口做一个SocketHandlerState类。
/// <summary>
/// Socket异步操作状态
/// </summary>
public class SocketAsyncResult : IAsyncResult
{
/// <summary>
/// 实例化Socket异步操作状态
/// </summary>
/// <param name="state"></param>
public SocketAsyncResult(object state)
{
AsyncState = state;
AsyncWaitHandle = new AutoResetEvent(false);
}
/// <summary>
/// 获取用户定义的对象，它限定或包含关于异步操作的信息。
/// </summary>
public object AsyncState { get; private set; }
/// <summary>
/// 获取用于等待异步操作完成的 System.Threading.WaitHandle。
/// </summary>
public WaitHandle AsyncWaitHandle { get; private set; }
/// <summary>
/// 获取一个值，该值指示异步操作是否同步完成。
/// </summary>
public bool CompletedSynchronously { get { return false; } }
/// <summary>
/// 获取一个值，该值指示异步操作是否已完成。
/// </summary>
public bool IsCompleted { get; internal set; }
}
然后开始编写发送数据相关函数。
这里我将发送数据的大小限制为最大65535。
只需发送长度为2的头信息即可把数据长度发送到对方。
/// <summary>
/// 开始发送
/// </summary>
/// <param name="data">要发送的数据</param>
/// <param name="offset">数据偏移</param>
/// <param name="count">发送长度</param>
/// <param name="stream">Socket网络流</param>
/// <param name="callback">回调函数</param>
/// <param name="state">自定义状态</param>
/// <returns>异步结果</returns>
public IAsyncResult BeginSend(byte[] data, int offset, int count, Stream stream, AsyncCallback callback, object state)
{
//data不能为null
if (data == null)
throw new ArgumentNullException("data");
//offset不能小于0和超过data长度
if (offset > data.Length || offset < 0)
throw new ArgumentOutOfRangeException("offset");
//count不能大于65535
if (count <= 0 || count > data.Length - offset || count > ushort.MaxValue)
throw new ArgumentOutOfRangeException("count");
//stream不能为null
if (stream == null)
throw new ArgumentNullException("stream");
//回调函数不能为null
if (callback == null)
throw new ArgumentNullException("callback");
//stream异常
if (!stream.CanWrite)
throw new ArgumentException("stream不支持写入。");
SocketAsyncResult result = new SocketAsyncResult(state);
//初始化SocketHandlerState
SocketHandlerState shs = new SocketHandlerState();
shs.Data = data;
shs.AsyncResult = result;
shs.Stream = stream;
shs.AsyncCallBack = callback;
shs.DataLength = 0;
//锁定SendQueue
//避免多线程同时发送数据
lock (SendQueue)
{
//添加状态
SendQueue.Add(shs);
//如果SendQueue数量大于1，则表示有数据尚未发送完成
if (SendQueue.Count > 1)
return result;
}
//获取数据长度
//ushort的最大值为65535
//转换为byte[]长度为2
var dataLength = BitConverter.GetBytes((ushort)data.Length);
//向对方发送长度为2的头信息，表示接下来要发送的数据长度
stream.Write(dataLength, 0, dataLength.Length);
//开始异步发送数据
stream.BeginWrite(shs.Data, 0, shs.Data.Length, EndWrite, shs).AsyncWaitHandle.WaitOne();
return result;
}
//stream异步结束写入
private void EndWrite(IAsyncResult ar)
{
SocketHandlerState state = (SocketHandlerState)ar.AsyncState;
//锁定StateSet
lock (StateSet)
StateSet.Add(state.AsyncResult, state);
try
{
state.Stream.EndWrite(ar);
}
catch
{
//出现Socket异常，发送失败
state.Completed = false;
//允许等待线程继续
((AutoResetEvent)state.AsyncResult.AsyncWaitHandle).Set();
//执行异步回调函数
state.AsyncCallBack(state.AsyncResult);
return;
}
//发送成功
state.Completed = true;
//允许等待线程继续
((AutoResetEvent)state.AsyncResult.AsyncWaitHandle).Set();
//执行异步回调函数
state.AsyncCallBack(state.AsyncResult);
//锁定SendQueue
lock (SendQueue)
{
SocketHandlerState prepare = null;
//移除当前发送完成的数据
SendQueue.Remove(state);
//如果SendQueue还有数据存在，则继续发送
if (SendQueue.Count > 0)
{
prepare = SendQueue[0];
}
if (prepare != null)
{
//获取数据长度
//ushort的最大值为65535
//转换为byte[]长度为2
var dataLength = BitConverter.GetBytes((ushort)prepare.Data.Length);
//向对方发送长度为2的头信息，表示接下来要发送的数据长度
prepare.Stream.Write(dataLength, 0, dataLength.Length);
//开始异步发送数据
prepare.Stream.BeginWrite(prepare.Data, 0, prepare.Data.Length, EndWrite, prepare).AsyncWaitHandle.WaitOne();
}
}
}
/// <summary>
/// 结束发送
/// </summary>
/// <param name="asyncResult">异步结果</param>
/// <returns>发送是否成功</returns>
public bool EndSend(IAsyncResult asyncResult)
{
//判断异步操作状态是否属于当前处理程序
if (!StateSet.ContainsKey(asyncResult))
throw new ArgumentException("无法识别的asyncResult。");
SocketHandlerState state = StateSet[asyncResult];
lock (StateSet)
StateSet.Remove(asyncResult);
return state.Completed;
}
接下来是接收数据的相关方法。
/// <summary>
/// 开始接收
/// </summary>
/// <param name="stream">Socket网络流</param>
/// <param name="callback">回调函数</param>
/// <param name="state">自定义状态</param>
/// <returns>异步结果</returns>
public IAsyncResult BeginReceive(Stream stream, AsyncCallback callback, object state)
{
//stream不能为null
if (stream == null)
throw new ArgumentNullException("stream");
//回调函数不能为null
if (callback == null)
throw new ArgumentNullException("callback");
//stream异常
if (!stream.CanRead)
throw new ArgumentException("stream不支持读取。");
SocketAsyncResult result = new SocketAsyncResult(state);
//初始化SocketHandlerState
SocketHandlerState shs = new SocketHandlerState();
shs.Data = new byte[2];
shs.AsyncResult = result;
shs.Stream = stream;
shs.AsyncCallBack = callback;
shs.Completed = true;
//开始异步接收长度为2的头信息
//该头信息包含要接收的主要数据长度
stream.BeginRead(shs.Data, 0, 2, EndRead, shs);
return result;
}
//stream异步结束读取
private void EndRead(IAsyncResult ar)
{
SocketHandlerState state = (SocketHandlerState)ar.AsyncState;
int dataLength;
try
{
dataLength = state.Stream.EndRead(ar);
}
catch
{
dataLength = 0;
}
//dataLength为0则表示Socket断开连接
if (dataLength == 0)
{
lock (StateSet)
StateSet.Add(state.AsyncResult, state);
//设定接收到的数据位空byte数组
state.Data = new byte[0];
//允许等待线程继续
((AutoResetEvent)state.AsyncResult.AsyncWaitHandle).Set();
//执行异步回调函数
state.AsyncCallBack(state.AsyncResult);
return;
}
//如果是已完成状态，则表示state.Data的数据是头信息
if (state.Completed)
{
//设定状态为未完成
state.Completed = false;
//已接收得数据长度为0
state.DataLength = 0;
//获取主要数据长度
var length = BitConverter.ToUInt16(state.Data, 0);
//初始化数据的byte数组
state.Data = new byte[length];
try
{
//开始异步接收主要数据
state.Stream.BeginRead(state.Data, 0, length, EndRead, state);
}
catch
{
//出现Socket异常
lock (StateSet)
StateSet.Add(state.AsyncResult, state);
state.Data = new byte[0];
((AutoResetEvent)state.AsyncResult.AsyncWaitHandle).Set();
state.AsyncCallBack(state.AsyncResult);
}
return;
}
//接收到主要数据
else
{
//判断是否接收了完整的数据
if (dataLength + state.DataLength != state.Data.Length)
{
//增加已接收数据长度
state.DataLength += dataLength;
try
{
//继续接收数据
state.Stream.BeginRead(state.Data, state.DataLength, state.Data.Length - state.DataLength, EndRead, state);
}
catch
{
//出现Socket异常
lock (StateSet)
StateSet.Add(state.AsyncResult, state);
state.Data = new byte[0];
((AutoResetEvent)state.AsyncResult.AsyncWaitHandle).Set();
state.AsyncCallBack(state.AsyncResult);
return;
}
return;
}
//接收完成
state.Completed = true;
lock (StateSet)
StateSet.Add(state.AsyncResult, state);
((AutoResetEvent)state.AsyncResult.AsyncWaitHandle).Set();
state.AsyncCallBack(state.AsyncResult);
}
}
/// <summary>
/// 结束接收
/// </summary>
/// <param name="asyncResult">异步结果</param>
/// <returns>接收到的数据</returns>
public byte[] EndReceive(IAsyncResult asyncResult)
{
//判断异步操作状态是否属于当前处理程序
if (!StateSet.ContainsKey(asyncResult))
throw new ArgumentException("无法识别的asyncResult。");
SocketHandlerState state = StateSet[asyncResult];
lock (StateSet)
StateSet.Remove(asyncResult);
return state.Data;
}
至此，SocketHandler的功能已经实现。
下一篇将为大家讲解服务器端的实现。
原文地址：http://www.cnblogs.com/Kation/archive/2013/03/06/2947145.html
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