异步客户端套接字示例
下面的示例程序创建一个连接到服务器的客户端。该客户端是用异步套接字生成的，因此在等待服务器返回响应时不挂起客户端应用程序的执行。该应用程序将字符串发送到服务器，然后在控制台显示该服务器返回的字符串。
C#
usingSystem;
usingSystem.Net;
usingSystem.Net.Sockets;
usingSystem.Threading;
usingSystem.Text;
//Stateobjectforreceivingdatafromremotedevice.
publicclassStateObject{
//Clientsocket.
publicSocketworkSocket=null;
//Sizeofreceivebuffer.
publicconstintBufferSize=256;
//Receivebuffer.
publicbyte[]buffer=newbyte[BufferSize];
//Receiveddatastring.
publicStringBuildersb=newStringBuilder();
}
publicclassAsynchronousClient{
//Theportnumberfortheremotedevice.
privateconstintport=11000;
//ManualResetEventinstancessignalcompletion.
privatestaticManualResetEventconnectDone=
newManualResetEvent(false);
privatestaticManualResetEventsendDone=
newManualResetEvent(false);
privatestaticManualResetEventreceiveDone=
newManualResetEvent(false);
//Theresponsefromtheremotedevice.
privatestaticStringresponse=String.Empty;
privatestaticvoidStartClient(){
//Connecttoaremotedevice.
try{
//Establishtheremoteendpointforthesocket.
//Thenameofthe
//remotedeviceis"host.contoso.com".
IPHostEntryipHostInfo=Dns.Resolve("host.contoso.com");
IPAddressipAddress=ipHostInfo.AddressList[0];
IPEndPointremoteEP=newIPEndPoint(ipAddress,port);
//CreateaTCP/IPsocket.
Socketclient=newSocket(AddressFamily.InterNetwork,
SocketType.Stream,ProtocolType.Tcp);
//Connecttotheremoteendpoint.
client.BeginConnect(remoteEP,
newAsyncCallback(ConnectCallback),client);
connectDone.WaitOne();
//Sendtestdatatotheremotedevice.
Send(client,"Thisisatest<EOF>");
sendDone.WaitOne();
//Receivetheresponsefromtheremotedevice.
Receive(client);
receiveDone.WaitOne();
//Writetheresponsetotheconsole.
Console.WriteLine("Responsereceived:{0}",response);
//Releasethesocket.
client.Shutdown(SocketShutdown.Both);
client.Close();
}catch(Exceptione){
Console.WriteLine(e.ToString());
}
}
privatestaticvoidConnectCallback(IAsyncResultar){
try{
//Retrievethesocketfromthestateobject.
Socketclient=(Socket)ar.AsyncState;
//Completetheconnection.
client.EndConnect(ar);
Console.WriteLine("Socketconnectedto{0}",
client.RemoteEndPoint.ToString());
//Signalthattheconnectionhasbeenmade.
connectDone.Set();
}catch(Exceptione){
Console.WriteLine(e.ToString());
}
}
privatestaticvoidReceive(Socketclient){
try{
//Createthestateobject.
StateObjectstate=newStateObject();
state.workSocket=client;
//Beginreceivingthedatafromtheremotedevice.
client.BeginReceive(state.buffer,0,StateObject.BufferSize,0,
newAsyncCallback(ReceiveCallback),state);
}catch(Exceptione){
Console.WriteLine(e.ToString());
}
}
privatestaticvoidReceiveCallback(IAsyncResultar){
try{
//Retrievethestateobjectandtheclientsocket
//fromtheasynchronousstateobject.
StateObjectstate=(StateObject)ar.AsyncState;
Socketclient=state.workSocket;
//Readdatafromtheremotedevice.
intbytesRead=client.EndReceive(ar);
if(bytesRead>0){
//Theremightbemoredata,sostorethedatareceivedsofar.
state.sb.Append(Encoding.ASCII.GetString(state.buffer,0,bytesRead));
//Gettherestofthedata.
client.BeginReceive(state.buffer,0,StateObject.BufferSize,0,
newAsyncCallback(ReceiveCallback),state);
}else{
//Allthedatahasarrived;putitinresponse.
if(state.sb.Length>1){
response=state.sb.ToString();
}
//Signalthatallbyteshavebeenreceived.
receiveDone.Set();
}
}catch(Exceptione){
Console.WriteLine(e.ToString());
}
}
privatestaticvoidSend(Socketclient,Stringdata){
//ConvertthestringdatatobytedatausingASCIIencoding.
byte[]byteData=Encoding.ASCII.GetBytes(data);
//Beginsendingthedatatotheremotedevice.
client.BeginSend(byteData,0,byteData.Length,0,
newAsyncCallback(SendCallback),client);
}
privatestaticvoidSendCallback(IAsyncResultar){
try{
//Retrievethesocketfromthestateobject.
Socketclient=(Socket)ar.AsyncState;
//Completesendingthedatatotheremotedevice.
intbytesSent=client.EndSend(ar);
Console.WriteLine("Sent{0}bytestoserver.",bytesSent);
//Signalthatallbyteshavebeensent.
sendDone.Set();
}catch(Exceptione){
Console.WriteLine(e.ToString());
}
}
publicstaticintMain(String[]args){
StartClient();
return0;
}
}
异步服务器套接字示例下面的示例程序创建一个接收来自客户端的连接请求的服务器。该服务器是用异步套接字生成的，
因此在等待来自客户端的连接时不挂起服务器应用程序的执行。该应用程序接收来自客户端的字符串，
在控制台显示该字符串，然后将该字符串回显到客户端。来自客户端的字符串必须包含字符串“<EOF>”，
以发出表示消息结尾的信号。
C#
复制代码
usingSystem;
usingSystem.Net;
usingSystem.Net.Sockets;
usingSystem.Text;
usingSystem.Threading;
//Stateobjectforreadingclientdataasynchronously
publicclassStateObject{
//Clientsocket.
publicSocketworkSocket=null;
//Sizeofreceivebuffer.
publicconstintBufferSize=1024;
//Receivebuffer.
publicbyte[]buffer=newbyte[BufferSize];
//Receiveddatastring.
publicStringBuildersb=newStringBuilder();
}
publicclassAsynchronousSocketListener{
//Threadsignal.
publicstaticManualResetEventallDone=newManualResetEvent(false);
publicAsynchronousSocketListener(){
}
publicstaticvoidStartListening(){
//Databufferforincomingdata.
byte[]bytes=newByte[1024];
//Establishthelocalendpointforthesocket.
//TheDNSnameofthecomputer
//runningthelisteneris"host.contoso.com".
IPHostEntryipHostInfo=Dns.Resolve(Dns.GetHostName());
IPAddressipAddress=ipHostInfo.AddressList[0];
IPEndPointlocalEndPoint=newIPEndPoint(ipAddress,11000);
//CreateaTCP/IPsocket.
Socketlistener=newSocket(AddressFamily.InterNetwork,
SocketType.Stream,ProtocolType.Tcp);
//Bindthesockettothelocalendpointandlistenforincomingconnections.
try{
listener.Bind(localEndPoint);
listener.Listen(100);
while(true){
//Settheeventtononsignaledstate.
allDone.Reset();
//Startanasynchronoussockettolistenforconnections.
Console.WriteLine("Waitingforaconnection...");
listener.BeginAccept(
newAsyncCallback(AcceptCallback),
listener);
//Waituntilaconnectionismadebeforecontinuing.
allDone.WaitOne();
}
}catch(Exceptione){
Console.WriteLine(e.ToString());
}
Console.WriteLine("nPressENTERtocontinue...");
Console.Read();
}
publicstaticvoidAcceptCallback(IAsyncResultar){
//Signalthemainthreadtocontinue.
allDone.Set();
//Getthesocketthathandlestheclientrequest.
Socketlistener=(Socket)ar.AsyncState;
Sockethandler=listener.EndAccept(ar);
//Createthestateobject.
StateObjectstate=newStateObject();
state.workSocket=handler;
handler.BeginReceive(state.buffer,0,StateObject.BufferSize,0,
newAsyncCallback(ReadCallback),state);
}
publicstaticvoidReadCallback(IAsyncResultar){
Stringcontent=String.Empty;
//Retrievethestateobjectandthehandlersocket
//fromtheasynchronousstateobject.
StateObjectstate=(StateObject)ar.AsyncState;
Sockethandler=state.workSocket;
//Readdatafromtheclientsocket.
intbytesRead=handler.EndReceive(ar);
if(bytesRead>0){
//Theremightbemoredata,sostorethedatareceivedsofar.
state.sb.Append(Encoding.ASCII.GetString(
state.buffer,0,bytesRead));
//Checkforend-of-filetag.Ifitisnotthere,read
//moredata.
content=state.sb.ToString();
if(content.IndexOf("<EOF>")>-1){
//Allthedatahasbeenreadfromthe
//client.Displayitontheconsole.
Console.WriteLine("Read{0}bytesfromsocket.nData:{1}",
content.Length,content);
//Echothedatabacktotheclient.
Send(handler,content);
}else{
//Notalldatareceived.Getmore.
handler.BeginReceive(state.buffer,0,StateObject.BufferSize,0,
newAsyncCallback(ReadCallback),state);
}
}
}
privatestaticvoidSend(Sockethandler,Stringdata){
//ConvertthestringdatatobytedatausingASCIIencoding.
byte[]byteData=Encoding.ASCII.GetBytes(data);
//Beginsendingthedatatotheremotedevice.
handler.BeginSend(byteData,0,byteData.Length,0,
newAsyncCallback(SendCallback),handler);
}
privatestaticvoidSendCallback(IAsyncResultar){
try{
//Retrievethesocketfromthestateobject.
Sockethandler=(Socket)ar.AsyncState;
//Completesendingthedatatotheremotedevice.
intbytesSent=handler.EndSend(ar);
Console.WriteLine("Sent{0}bytestoclient.",bytesSent);
handler.Shutdown(SocketShutdown.Both);
handler.Close();
}catch(Exceptione){
Console.WriteLine(e.ToString());
}
}
publicstaticintMain(String[]args){
StartListening();
return0;
}
}