Socket Class

Summary

Provides a managed implementation of the socket API, supporting synchronous and asynchronous operations for sending and receiving data across a network using protocols such as TCP and UDP.

The Socket class is the primary class for low-level network communication. It allows you to create and manage network connections, send and receive data, and handle various network-related events.

Inheritance

Object > Socket

Remarks

Use the Socket class to implement network-aware applications. You can use it to build clients, servers, or peer-to-peer applications. The class supports both blocking (synchronous) and non-blocking (asynchronous) I/O operations.

For higher-level network communication abstractions, consider using classes like TcpClient, UdpClient, or the System.Net.Http namespace.

Important: Managing socket resources properly is crucial. Ensure that you call the Close() or Dispose() method when you are finished with a Socket object to release unmanaged resources and prevent network port exhaustion.

Constructors

The Socket class has several constructors to initialize a new instance:

Socket(AddressFamily, SocketType, ProtocolType)
Socket(SocketInformation)

`Socket(AddressFamily, SocketType, ProtocolType)`

Initializes a new instance of the Socket class with the specified address family, socket type, and protocol.

public Socket(
    AddressFamily addressFamily,
    SocketType socketType,
    ProtocolType protocolType
);

Parameters

Parameter	Description
`addressFamily`	An `AddressFamily` enumeration value that specifies the namespace of the IP address. For example, `AddressFamily.InterNetwork` for IPv4 or `AddressFamily.InterNetworkV6` for IPv6.
`socketType`	A `SocketType` enumeration value that specifies the type of socket. For example, `SocketType.Stream` for TCP or `SocketType.Dgram` for UDP.
`protocolType`	A `ProtocolType` enumeration value that specifies the protocol to be used. For example, `ProtocolType.Tcp` or `ProtocolType.Udp`.

Properties

Key properties of the Socket class include:

Available: Gets the amount of data, in bytes, received on the socket that has not been read by the NetworkStream.
Blocking: Gets or sets a value indicating whether the Socket is in blocking mode.
Connected: Gets a value indicating whether the Socket is connected to a remote host.
Handle: Gets the native socket handle.
LocalEndPoint: Gets the local endpoint of the Socket.
RemoteEndPoint: Gets the remote endpoint of the Socket.

Methods

Commonly used methods:

Accept(): Accepts an incoming connection request.
Bind(EndPoint): Binds the Socket to a local endpoint.
Close(): Closes the socket connection.
Connect(EndPoint): Establishes a connection to a remote host.
Disconnect(Boolean): Disconnects the socket from the remote host.
Listen(Int32): Sets the maximum number of pending connections.
Receive(Byte[]): Receives data from the connected socket.
Send(Byte[]): Sends data to the connected socket.
SetSocketOption(SocketOptionLevel, SocketOptionName, Int32): Sets a socket option.
Shutdown(SocketShutdown): Disables sends, receives, or both on the socket.

`Connect(EndPoint remoteEP)`

Establishes a synchronous connection to a remote device.

public void Connect(
    EndPoint remoteEP
);

Example

try {
    IPAddress ipAddress = IPAddress.Parse("192.168.1.1");
    IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, 8080);
    Socket clientSocket = new Socket(ipEndPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
    clientSocket.Connect(ipEndPoint);
    Console.WriteLine("Connected to server.");
    // ... send/receive data ...
    clientSocket.Close();
} catch (Exception ex) {
    Console.WriteLine("Connection failed: " + ex.Message);
}

Events

The Socket class supports asynchronous operations through events, typically used with SocketAsyncEventArgs:

Completed: This event is raised when an asynchronous socket operation is completed.

System.Net.Sockets.Socket Class