NamedPipeClientStream.NumberOfServerInstances Property

Definition

Namespace:

System.IO.Pipes

Assembly:

System.IO.Pipes.dll

Source:

NamedPipeClientStream.Unix.cs

Gets the number of server instances that share the same pipe name.

public:
 property int NumberOfServerInstances { int get(); };

[System.Runtime.Versioning.SupportedOSPlatform("windows")]
public int NumberOfServerInstances { get; }

[<System.Runtime.Versioning.SupportedOSPlatform("windows")>]
member this.NumberOfServerInstances : int

Public ReadOnly Property NumberOfServerInstances As Integer

Property Value

Int32

The number of server instances that share the same pipe name.

Attributes

SupportedOSPlatformAttribute

Exceptions

InvalidOperationException

The pipe handle has not been set.

-or-

The current NamedPipeClientStream object has not yet connected to a NamedPipeServerStream object.

IOException

The pipe is broken or an I/O error occurred.

ObjectDisposedException

The underlying pipe handle is closed.

Examples

The following example demonstrates a method to send a string from a parent process to a child process using named pipes. In this example, a NamedPipeClientStream object is created in a child process, which then connects to a pipe on the local computer. The server example can be seen in the NamedPipeServerStream class. This example is part of a larger example provided for the NamedPipeServerStream and NamedPipeClientStream classes.

using System;
using System.IO;
using System.IO.Pipes;

class PipeClient
{
    static void Main(string[] args)
    {
        using (NamedPipeClientStream pipeClient =
            new NamedPipeClientStream(".", "testpipe", PipeDirection.In))
        {

            // Connect to the pipe or wait until the pipe is available.
            Console.Write("Attempting to connect to pipe...");
            pipeClient.Connect();

            Console.WriteLine("Connected to pipe.");
            Console.WriteLine("There are currently {0} pipe server instances open.",
               pipeClient.NumberOfServerInstances);
            using (StreamReader sr = new StreamReader(pipeClient))
            {
                // Display the read text to the console
                string temp;
                while ((temp = sr.ReadLine()) != null)
                {
                    Console.WriteLine("Received from server: {0}", temp);
                }
            }
        }
        Console.Write("Press Enter to continue...");
        Console.ReadLine();
    }
}

Imports System.IO
Imports System.IO.Pipes
Imports System.Security.Principal

Class PipeClient

    Shared Sub Main(ByVal args As String())

        Dim pipeClient As New NamedPipeClientStream("localhost", _
                    "testpipe", PipeDirection.In, PipeOptions.None)

        ' Connect to the pipe or wait until the pipe is available.
        Console.WriteLine("Attempting to connect to the pipe...")
        pipeClient.Connect()

        Console.WriteLine("Connect to the pipe.")
        Console.WriteLine("There are currently {0} pipe server instances open.", _
                          pipeClient.NumberOfServerInstances)

        Dim sr As New StreamReader(pipeClient)
        Dim temp As String

        temp = sr.ReadLine()
        While Not temp Is Nothing
            Console.WriteLine("Received from server: {0}", temp)
            temp = sr.ReadLine()
        End While
        Console.Write("Press Enter to continue...")
        Console.ReadLine()
    End Sub
End Class

Remarks

This property returns the number of server instances for the NamedPipeServerStream object that the current NamedPipeClientStream object has a handle to or is connected to. If the current NamedPipeClientStream object has not yet connected to a named pipe server, or if the current pipe handle has not yet been set, this property throws an InvalidOperationException.