Simple Socket Control(s) to Create Server-Client Applications

Mina W Alphonce

4.65/5 (18 votes)

Jun 21, 2005

CPOL

5 min read

142686

12120

Creating a simple control to be used as socket

Introduction

This simple project can be used instead of TcpClient, TcpListen - socket classes, because it's easy. You can create a server application in just three or four lines of code, and a client application in just two lines of code. This is the main idea of this article.

ConnectionSocket Class

Use this class instead of TcpClient class. Create an instance of it and use the function Connect to connect to a remote endpoint, and Send to send data. When the receive event fires, then there is a data that has been sent to you from the remote endpoint.

Connect
Function used to connect to a remote endpoint.

Host
string, specifies the IP, it can be (e.g. "127.0.0.1") or (e.g. "www.codeproject.com").
port
int, specifies the port in the remote endpoint that there is a socket listening to it.
Mode
One of the ConnectionMode enum, it is recommended to use SyncConnectAsyncRecv, other options can also be used.

Bind
This function is optional to use, use it to bind this socket to a specific endpoint. If you don't use this function the framework will bind the socket for you.
Send
Send the array of bytes to the remote endpoint, use this function for a connected socket only.
Receive
This function is used in Blocking mode, to receive data from the remote endpoint, if there is no data received then the thread will be blocked until the data is made available. (It is not recommended to use this function for receiving data.)

Length
int, the maximum length of the array that can be passed to the buffer. If the received data is greater than the Length, then the returned array will contain only the data of size Length, you must call Receive again to receive the other data. If the received data is less than the Length, then the returned array will be of the size of the data received.

Close
Use this function to close any created socket, for every created socket you must call close socket to close the socket.
Shutdown
Use this function to disable send or receive or both, the param is documented in the MSDN.

recieve event
Fired when there is data available to be received, the RecieveEventArg contains the data and the data length that is received, don't call Recieve in the recieve event, it will receive the next available data.
create event
Fired when the socket is created.
connect event
Fired in non Blocking mode (or AsyncConnectionxxxxxxxxx) when the connection is accepted by the remote endpoint.
shutdown event
Fired when calling the shutdown function.
send event
Fired after the send process ends.
close event
Fired if the close function is called or if the remote endpoint closes the connection or if there is any socket exception received. CloseEventArgs contains the exception and a string that specifies the error. You can use it in a message box.

ListenSocket Class

Use this call, instead of the TcpListen class. You can start listen, stop listen and accept connection from a remote end point.

Port
Use it to set the port to listen to. You must set it before calling start listen.
StartListen
Set the state of the socket to Listening state.

IsBlocked
If true, the accept event will not be fired when there is a request for connection, you must call the Accept function. If false, then the accept event fires.

StopListen
Stop listening.
close
Use this function to close any created socket, for every socket created, you must call close socket to close the socket.
Accept
Use this function if you pass true to StartListen. This function will block the thread, until a remote endpoint request connection is made.

create event
Fired after creating the socket.
close event
Fired if the close function is called or if the remote endpoint closes the connection or if there is any socket exception received. CloseEventArgs contains the exception and a string that specifies the error. You can use it in a message box.
accept event
Fired when a connection is accepted from the remote endpoint. The AcceptEventArgs contains a connected socket that is used to create a connection.

Example

Create a new Windows application project, named SimpleServer.
Right click on the Toolbox - add/remove item.
Click Browse - select sockets.dll (download it from this article).
Click OK.
The two classes ConnectSocket, ListenSocket are now in the Toolbox.

First drag one listen socket and one connect socket to your dialog. Change the port of the listen socket to 4000, from the properties. Change IsBlocked of the connect socket to false. Add a button, name it Listen, and handle the Click event:

private void button1_Click(object sender, System.EventArgs e)
{
  Socket_Listen.StratListen(false);
}

Add a TextBox for sending a message and add a Button named send, to send the text to the client, handle the clicked event:

private void button2_Click(object sender, System.EventArgs e)
{
   byte[] buff = Socktes.ByesConvertor.GetBytes(textBox1.Text);
   Socket_Connection.Send(buff);
}
//You can use Encoding class to get an array of bytes, but the BytesConvertor 
//class has all the functions we need to use in the socket classes.

Add a ListBox to add the received messages.

Let's get to the main code of the project. For the listen socket, handle the accept event:

private void Socket_Listen_accept(object Sender, Socktes.AcceptEventArgs e)
{
    Socket_Connection.SocketHandle = e.ConnectedSocket;
}
// e.ConnectedSocket contain a connected socket, 
// set the Connectsocket instance
// to the Connected socket received from the 
// accept event.

For the connect socket, handle the receive event:

private void Socket_Connection_recieve(object Sender, 
                               Socktes.RecieveEventArgs e)
{
    string s = Socktes.ByesConvertor.BytesToString(e.Data);
    listBox1.Items.Add(s);
}
// recieve the data from the socket and 
// add it to the list box.

That's all the code for the server, now let's go to the client.

Create a new Windows application, named SimpleClient. Drag one connect socket to your form, change IsBlocked to false. Add a Button, name it connect, now handle the Click event:

private void button1_Click(object sender, System.EventArgs e)
{
    Socket_Connection.Connect("127.0.0.1",4000);
}

Add a TextBox and a Button, handle the Click event:

private void button2_Click(object sender, System.EventArgs e)
{
    byte[] b = Socktes.ByesConvertor.GetBytes(textBox1.Text);
    Socket_Connection.Send(b);
}

Add a ListBox, handle the receive event of the connect socket:

private void Socket_Connection_recieve(object Sender, Socktes.RecieveEventArgs e)
{
    string s = Socktes.ByesConvertor.BytesToString(e.Data);
    listBox1.Items.Add(s);
}

That's all about the client and the server. Sorry for not commenting the demo, but Socket.dll is well commented.