C＋＋/CLI程序进程之间的通讯

客户端套接字

　　现在，让我们来看一下客户端程序（参见例2）。在连接到服务端之后，客户端将发送一对随机的整数，并且在发送下一对之前等待返回的结果。此处我们所看到的是服务端与客户端的同步通讯，客户端在接收到前一对值的结果之前，是不会发送另一对新值的。

　　例2：

using namespace System; using namespace System::IO; using namespace System::Net; using namespace System::Net::Sockets; using namespace System::Threading; int main(array<String^>^ argv) { 　if (argv->Length != 2) 　{ 　　Console::WriteLine("Usage: Client port message-count"); 　　Environment::Exit(1); 　} 　int port = 0; 　try 　{ 　　port = Int32::Parse(argv[0]); 　} 　catch (FormatException^ e) 　{ 　　Console::WriteLine("Port number {0} is ill-formed", argv[0]); 　　Environment::Exit(2); 　} 　if (port < IPEndPoint::MinPort || port > IPEndPoint::MaxPort) 　{ 　　Console::WriteLine("Port number must be in the range {0}-{1}",IPEndPoint::MinPort, IPEndPoint::MaxPort); 　　Environment::Exit(3); 　} 　int messageCount = 0; 　try 　{ 　　messageCount = Int32::Parse(argv[1]); 　} 　catch (FormatException^ e) 　{ 　　Console::WriteLine("Message count {0} is ill-formed", argv[1]); 　　Environment::Exit(4); 　} 　IPAddress^ ipAddress = nullptr; 　try 　{ 　　/*1*/ ipAddress = Dns::GetHostEntry(Dns::GetHostName())->AddressList[0]; 　　/*2*/ IPEndPoint^ ipEndpoint = gcnew IPEndPoint(ipAddress, port); 　　/*3*/ Socket^ clientSocket = gcnew Socket(AddressFamily::InterNetwork, 　　SocketType::Stream, ProtocolType::Tcp); 　　/*4*/ clientSocket->Connect(ipEndpoint); 　　NetworkStream^ netStream = gcnew NetworkStream(clientSocket); 　　BinaryReader^ br = gcnew BinaryReader(netStream); 　　BinaryWriter^ bw = gcnew BinaryWriter(netStream); 　　int value1, value2; 　　int result; 　　Random^ random = gcnew Random; 　　(int i = 1; i <= messageCount; ++i) 　　{ 　　　/*5*/ value1 = static_cast<int>(random->NextDouble() * 100); 　　　/*6*/ value2 = static_cast<int>(random->NextDouble() * 100); 　 　　　/*7*/ bw->Write(value1); 　　　/*8*/ bw->Write(value2); 　　　Console::Write("Sent values {0,3} and {1,3}",value1, value2); 　 　　　/*9*/ result = br->ReadInt32(); 　　　Console::WriteLine(", received result {0,3}", result); 　　　/*10*/ Thread::Sleep(3000); 　　} 　　/*11*/ clientSocket->Shutdown(SocketShutdown::Both); 　　Console::WriteLine("Notified server we're shutting down"); 　　/*12*/ clientSocket->Close(); 　　/*13*/ netStream->Close(); 　　Console::WriteLine("Shutting down client"); 　} 　/*14*/ catch (SocketException^ e) 　{ 　　Console::WriteLine("Request to connect to {0} on port {1} failed"+ "\nbecause of {2}", ipAddress, port, e); 　　Environment::Exit(5); 　} }

　　如同服务端一样，客户端取得一个IP地址，把它与端口号绑定以生成一个IPEndPoint，并连接到服务端，而服务端在此之前一直处于阻塞监听模式。

　　在每一个发送与接收操作之间，我们有意延迟三秒，以便观察程序的输出。

　　以下是一个服务端程序使用端口2500时的输出：

Server listener blocking status is True New connection accepted Received values 42 and 69, sent result 111 Received values 66 and 71, sent result 137 Received values 7 and 93, sent result 100 Received values 43 and 65, sent result 108 Received values 45 and 3, sent result 48 Shutting down server

　　而以下是对应的客户端程序，在发送5对值之后的输出：

Sent values 42 and 69, received result 111 Sent values 66 and 71, received result 137 Sent values 7 and 93, received result 100 Sent values 43 and 65, received result 108 Sent values 45 and 3, received result 48 Notified server we're shutting down Shutting down client