Represents a serial port resource.
(in System.dll)
Visual Basic (Declaration)
Public Class SerialPort _
Inherits Component
Dim instance As SerialPort
public class SerialPort : Component
public ref class SerialPort : public Component
public class SerialPort extends Component
Use this class to control a serial port file resource. This class provides synchronous and event-driven I/O, access to pin and break states, and access to serial driver properties. Additionally, the functionality of this class can be wrapped in an internal Stream object, accessible through the BaseStream property, and passed to classes that wrap or use streams.
The SerialPort class supports the following encodings: ASCIIEncoding, UTF8Encoding, UnicodeEncoding, UTF32Encoding, and any encoding defined in mscorlib.dll where the code page is less than 50000 or the code page is 54936. You can use alternate encodings, but you must use the ReadByte or Write method and perform the encoding yourself.
The following code example demonstrates the use of the SerialPort class to allow two users to chat from two separate computers connected by a null modem cable. In this example, the users are prompted for the port settings and a username before chatting. Both computers must be executing the program to achieve full functionality of this example.
Imports System
Imports System.IO.Ports
Imports System.Threading
Public Class PortChat
Shared _continue As Boolean
Shared _serialPort As SerialPort
Public Shared Sub Main()
Dim name As String
Dim message As String
Dim sComparer As StringComparer = StringComparer.OrdinalIgnoreCase
Dim readThread As Thread = New Thread(AddressOf Read)
' Create a new SerialPort object with default settings.
_serialPort = New SerialPort()
' Allow the user to set the appropriate properties.
_serialPort.PortName = SetPortName(_serialPort.PortName)
_serialPort.BaudRate = SetPortBaudRate(_serialPort.BaudRate)
_serialPort.Parity = SetPortParity(_serialPort.Parity)
_serialPort.DataBits = SetPortDataBits(_serialPort.DataBits)
_serialPort.StopBits = SetPortStopBits(_serialPort.StopBits)
_serialPort.Handshake = SetPortHandshake(_serialPort.Handshake)
' Set the read/write timeouts
_serialPort.ReadTimeout = 500
_serialPort.WriteTimeout = 500
_serialPort.Open()
_continue = True
readThread.Start()
Console.Write("Name: ")
name = Console.ReadLine()
Console.WriteLine("Type QUIT to exit")
While (_continue)
message = Console.ReadLine()
If sComparer.Equals("quit", message) Then
_continue = False
Else
_serialPort.WriteLine( _
String.Format("<{0}>: {1}", name, message))
End If
end while
readThread.Join()
_serialPort.Close()
End Sub
Public Shared Sub Read()
While (_continue)
Try
Dim message As String = _serialPort.ReadLine()
Console.WriteLine(message)
Catch ex As TimeoutException
' Do nothing
End Try
End While
End Sub
Public Shared Function SetPortName(ByVal defaultPortName As String) As String
Dim newPortName As String
Console.WriteLine("Available Ports:")
Dim s As String
For Each s In SerialPort.GetPortNames()
Console.WriteLine(" {0}", s)
Next s
Console.Write("COM port({0}): ", defaultPortName)
newPortName = Console.ReadLine()
If newPortName = "" Then
newPortName = defaultPortName
End If
Return newPortName
End Function
Public Shared Function SetPortBaudRate(ByVal defaultPortBaudRate As Integer) As Integer
Dim newBaudRate As String
Console.Write("Baud Rate({0}): ", defaultPortBaudRate)
newBaudRate = Console.ReadLine()
If newBaudRate = "" Then
newBaudRate = defaultPortBaudRate.ToString()
End If
Return Integer.Parse(newBaudRate)
End Function
Public Shared Function SetPortParity(ByVal defaultPortParity As Parity) As Parity
Dim newParity As String
Console.WriteLine("Available Parity options:")
Dim s As String
For Each s In [Enum].GetNames(GetType(Parity))
Console.WriteLine(" {0}", s)
Next s
Console.Write("Parity({0}):", defaultPortParity.ToString())
newparity = Console.ReadLine()
If newparity = "" Then
newparity = defaultPortParity.ToString()
End If
Return CType([Enum].Parse(GetType(Parity), newParity), Parity)
End Function
Public Shared Function SetPortDataBits(ByVal defaultPortDataBits As Integer) As Integer
Dim newDataBits As String
Console.Write("Data Bits({0}): ", defaultPortDataBits)
newDataBits = Console.ReadLine()
If newDataBits = "" Then
newDataBits = defaultPortDataBits.ToString()
End If
Return Integer.Parse(newDataBits)
End Function
Public Shared Function SetPortStopBits(ByVal defaultPortStopBits As StopBits) As StopBits
Dim newStopBits As String
Console.WriteLine("Available Stop Bits options:")
Dim s As String
For Each s In [Enum].GetNames(GetType(StopBits))
Console.WriteLine(" {0}", s)
Next s
Console.Write("Stop Bits({0}):", defaultPortStopBits.ToString())
newStopBits = Console.ReadLine()
If newStopBits = "" Then
newStopBits = defaultPortStopBits.ToString()
End If
Return CType([Enum].Parse(GetType(StopBits), newStopBits), StopBits)
End Function
Public Shared Function SetPortHandshake(ByVal defaultPortHandshake As Handshake) As Handshake
Dim newHandshake As String
Console.WriteLine("Available Handshake options:")
Dim s As String
For Each s In [Enum].GetNames(GetType(Handshake))
Console.WriteLine(" {0}", s)
Next s
Console.Write("Stop Bits({0}):", defaultPortHandshake.ToString())
newHandshake = Console.ReadLine()
If newHandshake = "" Then
newHandshake = defaultPortHandshake.ToString()
End If
Return CType([Enum].Parse(GetType(Handshake), newHandshake), Handshake)
End Function
End Class
using System;
using System.IO.Ports;
using System.Threading;
public class PortChat
{
static bool _continue;
static SerialPort _serialPort;
public static void Main()
{
string name;
string message;
StringComparer stringComparer = StringComparer.OrdinalIgnoreCase;
Thread readThread = new Thread(Read);
// Create a new SerialPort object with default settings.
_serialPort = new SerialPort();
// Allow the user to set the appropriate properties.
_serialPort.PortName = SetPortName(_serialPort.PortName);
_serialPort.BaudRate = SetPortBaudRate(_serialPort.BaudRate);
_serialPort.Parity = SetPortParity(_serialPort.Parity);
_serialPort.DataBits = SetPortDataBits(_serialPort.DataBits);
_serialPort.StopBits = SetPortStopBits(_serialPort.StopBits);
_serialPort.Handshake = SetPortHandshake(_serialPort.Handshake);
// Set the read/write timeouts
_serialPort.ReadTimeout = 500;
_serialPort.WriteTimeout = 500;
_serialPort.Open();
_continue = true;
readThread.Start();
Console.Write("Name: ");
name = Console.ReadLine();
Console.WriteLine("Type QUIT to exit");
while (_continue)
{
message = Console.ReadLine();
if (stringComparer.Equals("quit", message))
{
_continue = false;
}
else
{
_serialPort.WriteLine(
String.Format("<{0}>: {1}", name, message) );
}
}
readThread.Join();
_serialPort.Close();
}
public static void Read()
{
while (_continue)
{
try
{
string message = _serialPort.ReadLine();
Console.WriteLine(message);
}
catch (TimeoutException) { }
}
}
public static string SetPortName(string defaultPortName)
{
string portName;
Console.WriteLine("Available Ports:");
foreach (string s in SerialPort.GetPortNames())
{
Console.WriteLine(" {0}", s);
}
Console.Write("COM port({0}): ", defaultPortName);
portName = Console.ReadLine();
if (portName == "")
{
portName = defaultPortName;
}
return portName;
}
public static int SetPortBaudRate(int defaultPortBaudRate)
{
string baudRate;
Console.Write("Baud Rate({0}): ", defaultPortBaudRate);
baudRate = Console.ReadLine();
if (baudRate == "")
{
baudRate = defaultPortBaudRate.ToString();
}
return int.Parse(baudRate);
}
public static Parity SetPortParity(Parity defaultPortParity)
{
string parity;
Console.WriteLine("Available Parity options:");
foreach (string s in Enum.GetNames(typeof(Parity)))
{
Console.WriteLine(" {0}", s);
}
Console.Write("Parity({0}):", defaultPortParity.ToString());
parity = Console.ReadLine();
if (parity == "")
{
parity = defaultPortParity.ToString();
}
return (Parity)Enum.Parse(typeof(Parity), parity);
}
public static int SetPortDataBits(int defaultPortDataBits)
{
string dataBits;
Console.Write("Data Bits({0}): ", defaultPortDataBits);
dataBits = Console.ReadLine();
if (dataBits == "")
{
dataBits = defaultPortDataBits.ToString();
}
return int.Parse(dataBits);
}
public static StopBits SetPortStopBits(StopBits defaultPortStopBits)
{
string stopBits;
Console.WriteLine("Available Stop Bits options:");
foreach (string s in Enum.GetNames(typeof(StopBits)))
{
Console.WriteLine(" {0}", s);
}
Console.Write("Stop Bits({0}):", defaultPortStopBits.ToString());
stopBits = Console.ReadLine();
if (stopBits == "")
{
stopBits = defaultPortStopBits.ToString();
}
return (StopBits)Enum.Parse(typeof(StopBits), stopBits);
}
public static Handshake SetPortHandshake(Handshake defaultPortHandshake)
{
string handshake;
Console.WriteLine("Available Handshake options:");
foreach (string s in Enum.GetNames(typeof(Handshake)))
{
Console.WriteLine(" {0}", s);
}
Console.Write("Stop Bits({0}):", defaultPortHandshake.ToString());
handshake = Console.ReadLine();
if (handshake == "")
{
handshake = defaultPortHandshake.ToString();
}
return (Handshake)Enum.Parse(typeof(Handshake), handshake);
}
}
System..::.Object
System..::.MarshalByRefObject
System.ComponentModel..::.Component
System.IO.Ports..::.SerialPort
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0
.NET Compact Framework
Supported in: 3.5, 2.0
Reference