Cómo: Usar canalizaciones anónimas para la comunicación entre procesos locales
Las canalizaciones anónimas proporcionan menos funcionalidad que canalizaciones con nombre, pero también requieren menos esfuerzo. Puede utilizar las canalizaciones anónimas para facilitar la comunicación entre procesos en un equipo local. No se puede utilizar las canalizaciones anónimas para la comunicación a través de una red.
Ejemplo
En el ejemplo siguiente se muestra una manera de enviar una cadena de un proceso primario a un proceso secundario mediante canalizaciones anónimas. En este ejemplo se crea un objeto AnonymousPipeServerStream en un proceso primario con un valor PipeDirection de Out. A continuación, el proceso primario crea un proceso secundario mediante un identificador de cliente para crear un objeto AnonymousPipeClientStream. El proceso secundario tiene un valor PipeDirection de In.
El proceso primario envía a continuación una cadena proporcionada por usuario al proceso secundario. La cadena se muestra a la consola en el proceso secundario.
En el ejemplo siguiente se muestra el proceso del servidor.
Imports System
Imports System.IO
Imports System.IO.Pipes
Imports System.Diagnostics
Class PipeServer
Shared Sub Main()
Dim pipeClient As New Process()
pipeClient.StartInfo.FileName = "pipeClient.exe"
Using pipeServer As New AnonymousPipeServerStream(PipeDirection.Out, _
HandleInheritability.Inheritable)
' Show that anonymous pipes do not support Message mode.
Try
Console.WriteLine("[SERVER] Setting ReadMode to ""Message"".")
pipeServer.ReadMode = PipeTransmissionMode.Message
Catch e As NotSupportedException
Console.WriteLine("[SERVER] Exception:\n {0}", e.Message)
End Try
Console.WriteLine("[SERVER] Current TransmissionMode: {0}.",
pipeServer.TransmissionMode)
' Pass the client process a handle to the server.
pipeClient.StartInfo.Arguments = pipeServer.GetClientHandleAsString()
pipeClient.StartInfo.UseShellExecute = false
pipeClient.Start()
pipeServer.DisposeLocalCopyOfClientHandle()
Try
' Read user input and send that to the client process.
Using sw As New StreamWriter(pipeServer)
sw.AutoFlush = true
' Send a 'sync message' and wait for client to receive it.
sw.WriteLine("SYNC")
pipeServer.WaitForPipeDrain()
' Send the console input to the client process.
Console.Write("[SERVER] Enter text: ")
sw.WriteLine(Console.ReadLine())
End Using
Catch e As IOException
' Catch the IOException that is raised if the pipe is broken
' or disconnected.
Console.WriteLine("[SERVER] Error: {0}", e.Message)
End Try
End Using
pipeClient.WaitForExit()
pipeClient.Close()
Console.WriteLine("[SERVER] Client quit. Server terminating.")
End Sub
End Class
using System;
using System.IO;
using System.IO.Pipes;
using System.Diagnostics;
class PipeServer
{
static void Main()
{
Process pipeClient = new Process();
pipeClient.StartInfo.FileName = "pipeClient.exe";
using (AnonymousPipeServerStream pipeServer =
new AnonymousPipeServerStream(PipeDirection.Out,
HandleInheritability.Inheritable))
{
// Show that anonymous pipes do not support Message mode.
try
{
Console.WriteLine("[SERVER] Setting ReadMode to \"Message\".");
pipeServer.ReadMode = PipeTransmissionMode.Message;
}
catch (NotSupportedException e)
{
Console.WriteLine("[SERVER] Exception:\n {0}", e.Message);
}
Console.WriteLine("[SERVER] Current TransmissionMode: {0}.",
pipeServer.TransmissionMode);
// Pass the client process a handle to the server.
pipeClient.StartInfo.Arguments =
pipeServer.GetClientHandleAsString();
pipeClient.StartInfo.UseShellExecute = false;
pipeClient.Start();
pipeServer.DisposeLocalCopyOfClientHandle();
try
{
// Read user input and send that to the client process.
using (StreamWriter sw = new StreamWriter(pipeServer))
{
sw.AutoFlush = true;
// Send a 'sync message' and wait for client to receive it.
sw.WriteLine("SYNC");
pipeServer.WaitForPipeDrain();
// Send the console input to the client process.
Console.Write("[SERVER] Enter text: ");
sw.WriteLine(Console.ReadLine());
}
}
// Catch the IOException that is raised if the pipe is broken
// or disconnected.
catch (IOException e)
{
Console.WriteLine("[SERVER] Error: {0}", e.Message);
}
}
pipeClient.WaitForExit();
pipeClient.Close();
Console.WriteLine("[SERVER] Client quit. Server terminating.");
}
}
#using <System.dll>
#using <System.Core.dll>
using namespace System;
using namespace System::IO;
using namespace System::IO::Pipes;
using namespace System::Diagnostics;
ref class PipeServer
{
public:
static void Main()
{
Process^ pipeClient = gcnew Process();
pipeClient->StartInfo->FileName = "pipeClient.exe";
AnonymousPipeServerStream^ pipeServer =
gcnew AnonymousPipeServerStream(PipeDirection::Out,
HandleInheritability::Inheritable);
// Show that anonymous pipes do not support Message mode.
try
{
Console::WriteLine("[SERVER] Setting ReadMode to \"Message\".");
pipeServer->ReadMode = PipeTransmissionMode::Message;
}
catch (NotSupportedException^ e)
{
Console::WriteLine("[SERVER] Exception:\n {0}", e->Message);
}
Console::WriteLine("[SERVER] Current TransmissionMode: {0}.",
pipeServer->TransmissionMode);
// Pass the client process a handle to the server.
pipeClient->StartInfo->Arguments =
pipeServer->GetClientHandleAsString();
pipeClient->StartInfo->UseShellExecute = false;
pipeClient->Start();
pipeServer->DisposeLocalCopyOfClientHandle();
try
{
// Read user input and send that to the client process.
StreamWriter^ sw = gcnew StreamWriter(pipeServer);
sw->AutoFlush = true;
// Send a 'sync message' and wait for client to receive it.
sw->WriteLine("SYNC");
pipeServer->WaitForPipeDrain();
// Send the console input to the client process.
Console::Write("[SERVER] Enter text: ");
sw->WriteLine(Console::ReadLine());
sw->Close();
}
// Catch the IOException that is raised if the pipe is broken
// or disconnected.
catch (IOException^ e)
{
Console::WriteLine("[SERVER] Error: {0}", e->Message);
}
pipeServer->Close();
pipeClient->WaitForExit();
pipeClient->Close();
Console::WriteLine("[SERVER] Client quit. Server terminating.");
}
};
int main()
{
PipeServer::Main();
}
En el ejemplo siguiente se muestra el proceso del cliente. El proceso de servidor inicia el proceso de cliente y da un identificador de cliente a ese proceso. El ejecutable resultante del código de cliente debe denominarse pipeClient.exe y copiarse en el mismo directorio que el ejecutable del servidor antes de ejecutar el proceso de servidor.
Imports System
Imports System.IO
Imports System.IO.Pipes
Class PipeClient
Shared Sub Main(args() as String)
If args.Length > 0 Then
Using pipeClient As New AnonymousPipeClientStream(PipeDirection.In, args(0))
' Show that anonymous Pipes do not support Message mode.
Try
Console.WriteLine("[CLIENT] Setting ReadMode to ""Message"".")
pipeClient.ReadMode = PipeTransmissionMode.Message
Catch e As NotSupportedException
Console.WriteLine("[CLIENT] Execption:" + vbNewLine + " {0}", e.Message)
End Try
Console.WriteLine("[CLIENT] Current TransmissionMode: {0}.", _
pipeClient.TransmissionMode)
Using sr As New StreamReader(pipeClient)
' Display the read text to the console
Dim temp As String
' Wait for 'sync message' from the server.
Do
Console.WriteLine("[CLIENT] Wait for sync...")
temp = sr.ReadLine()
Loop While temp.StartsWith("SYNC") = False
' Read the server data and echo to the console.
temp = sr.ReadLine()
While Not temp = Nothing
Console.WriteLine("[CLIENT] Echo: " + temp)
temp = sr.ReadLine()
End While
End Using
End Using
End If
Console.Write("[CLIENT] Press Enter to continue...")
Console.ReadLine()
End Sub
End Class
using System;
using System.IO;
using System.IO.Pipes;
class PipeClient
{
static void Main(string[] args)
{
if (args.Length > 0)
{
using (PipeStream pipeClient =
new AnonymousPipeClientStream(PipeDirection.In, args[0]))
{
// Show that anonymous Pipes do not support Message mode.
try
{
Console.WriteLine("[CLIENT] Setting ReadMode to \"Message\".");
pipeClient.ReadMode = PipeTransmissionMode.Message;
}
catch (NotSupportedException e)
{
Console.WriteLine("[CLIENT] Execption:\n {0}", e.Message);
}
Console.WriteLine("[CLIENT] Current TransmissionMode: {0}.",
pipeClient.TransmissionMode);
using (StreamReader sr = new StreamReader(pipeClient))
{
// Display the read text to the console
string temp;
// Wait for 'sync message' from the server.
do
{
Console.WriteLine("[CLIENT] Wait for sync...");
temp = sr.ReadLine();
}
while (!temp.StartsWith("SYNC"));
// Read the server data and echo to the console.
while ((temp = sr.ReadLine()) != null)
{
Console.WriteLine("[CLIENT] Echo: " + temp);
}
}
}
}
Console.Write("[CLIENT] Press Enter to continue...");
Console.ReadLine();
}
}
#using <System.Core.dll>
using namespace System;
using namespace System::IO;
using namespace System::IO::Pipes;
ref class PipeClient
{
public:
static void Main(array<String^>^ args)
{
if (args->Length > 1)
{
PipeStream^ pipeClient = gcnew AnonymousPipeClientStream(PipeDirection::In, args[1]);
// Show that anonymous Pipes do not support Message mode.
try
{
Console::WriteLine("[CLIENT] Setting ReadMode to \"Message\".");
pipeClient->ReadMode = PipeTransmissionMode::Message;
}
catch (NotSupportedException^ e)
{
Console::WriteLine("[CLIENT] Execption:\n {0}", e->Message);
}
Console::WriteLine("[CLIENT] Current TransmissionMode: {0}.",
pipeClient->TransmissionMode);
StreamReader^ sr = gcnew StreamReader(pipeClient);
// Display the read text to the console
String^ temp;
// Wait for 'sync message' from the server.
do
{
Console::WriteLine("[CLIENT] Wait for sync...");
temp = sr->ReadLine();
}
while (!temp->StartsWith("SYNC"));
// Read the server data and echo to the console.
while ((temp = sr->ReadLine()) != nullptr)
{
Console::WriteLine("[CLIENT] Echo: " + temp);
}
sr->Close();
pipeClient->Close();
}
Console::Write("[CLIENT] Press Enter to continue...");
Console::ReadLine();
}
};
int main()
{
array<String^>^ args = Environment::GetCommandLineArgs();
PipeClient::Main(args);
}
Vea también
Tareas
Cómo: Usar canalizaciones con nombre para la comunicación entre procesos a través de una red