SerialPort Classe

Definizione

public ref class SerialPort : System::ComponentModel::Component

public class SerialPort : System.ComponentModel.Component

type SerialPort = class
    inherit Component

Public Class SerialPort
Inherits Component

Ereditarietà

Object

MarshalByRefObject

Component

SerialPort

Esempio

Nell'esempio di codice seguente viene illustrato l'uso della SerialPort classe per consentire a due utenti di chattare da due computer separati collegati da un cavo modem Null. In questo esempio, agli utenti vengono richieste le impostazioni della porta e un nome utente prima della chat. Entrambi i computer devono eseguire il programma per ottenere funzionalità complete di questo esempio.

// Use this code inside a project created with the Visual C# > Windows Desktop > Console Application template.
// Replace the code in Program.cs with this code.

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) { }
        }
    }

    // Display Port values and prompt user to enter a port.
    public static string SetPortName(string defaultPortName)
    {
        string portName;

        Console.WriteLine("Available Ports:");
        foreach (string s in SerialPort.GetPortNames())
        {
            Console.WriteLine("   {0}", s);
        }

        Console.Write("Enter COM port value (Default: {0}): ", defaultPortName);
        portName = Console.ReadLine();

        if (portName == "" || !(portName.ToLower()).StartsWith("com"))
        {
            portName = defaultPortName;
        }
        return portName;
    }
    // Display BaudRate values and prompt user to enter a value.
    public static int SetPortBaudRate(int defaultPortBaudRate)
    {
        string baudRate;

        Console.Write("Baud Rate(default:{0}): ", defaultPortBaudRate);
        baudRate = Console.ReadLine();

        if (baudRate == "")
        {
            baudRate = defaultPortBaudRate.ToString();
        }

        return int.Parse(baudRate);
    }

    // Display PortParity values and prompt user to enter a value.
    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("Enter Parity value (Default: {0}):", defaultPortParity.ToString(), true);
        parity = Console.ReadLine();

        if (parity == "")
        {
            parity = defaultPortParity.ToString();
        }

        return (Parity)Enum.Parse(typeof(Parity), parity, true);
    }
    // Display DataBits values and prompt user to enter a value.
    public static int SetPortDataBits(int defaultPortDataBits)
    {
        string dataBits;

        Console.Write("Enter DataBits value (Default: {0}): ", defaultPortDataBits);
        dataBits = Console.ReadLine();

        if (dataBits == "")
        {
            dataBits = defaultPortDataBits.ToString();
        }

        return int.Parse(dataBits.ToUpperInvariant());
    }

    // Display StopBits values and prompt user to enter a value.
    public static StopBits SetPortStopBits(StopBits defaultPortStopBits)
    {
        string stopBits;

        Console.WriteLine("Available StopBits options:");
        foreach (string s in Enum.GetNames(typeof(StopBits)))
        {
            Console.WriteLine("   {0}", s);
        }

        Console.Write("Enter StopBits value (None is not supported and \n" +
         "raises an ArgumentOutOfRangeException. \n (Default: {0}):", defaultPortStopBits.ToString());
        stopBits = Console.ReadLine();

        if (stopBits == "" )
        {
            stopBits = defaultPortStopBits.ToString();
        }

        return (StopBits)Enum.Parse(typeof(StopBits), stopBits, true);
    }
    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("Enter Handshake value (Default: {0}):", defaultPortHandshake.ToString());
        handshake = Console.ReadLine();

        if (handshake == "")
        {
            handshake = defaultPortHandshake.ToString();
        }

        return (Handshake)Enum.Parse(typeof(Handshake), handshake, true);
    }
}

' Use this code inside a project created with the Visual Basic > Windows Desktop > Console Application template.
' Replace the default code in Module1.vb with this code. Then right click the project in Solution Explorer,
' select Properties, and set the Startup Object to PortChat.

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 stringComparer__1 As StringComparer = StringComparer.OrdinalIgnoreCase
        Dim readThread As 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 stringComparer__1.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 generatedExceptionName As TimeoutException
            End Try
        End While
    End Sub

    ' Display Port values and prompt user to enter a port.
    Public Shared Function SetPortName(defaultPortName As String) As String
        Dim portName As String

        Console.WriteLine("Available Ports:")
        For Each s As String In SerialPort.GetPortNames()
            Console.WriteLine("   {0}", s)
        Next

        Console.Write("Enter COM port value (Default: {0}): ", defaultPortName)
        portName = Console.ReadLine()

        If portName = "" OrElse Not (portName.ToLower()).StartsWith("com") Then
            portName = defaultPortName
        End If
        Return portName
    End Function
    ' Display BaudRate values and prompt user to enter a value.
    Public Shared Function SetPortBaudRate(defaultPortBaudRate As Integer) As Integer
        Dim baudRate As String

        Console.Write("Baud Rate(default:{0}): ", defaultPortBaudRate)
        baudRate = Console.ReadLine()

        If baudRate = "" Then
            baudRate = defaultPortBaudRate.ToString()
        End If

        Return Integer.Parse(baudRate)
    End Function

    ' Display PortParity values and prompt user to enter a value.
    Public Shared Function SetPortParity(defaultPortParity As Parity) As Parity
        Dim parity As String

        Console.WriteLine("Available Parity options:")
        For Each s As String In [Enum].GetNames(GetType(Parity))
            Console.WriteLine("   {0}", s)
        Next

        Console.Write("Enter Parity value (Default: {0}):", defaultPortParity.ToString(), True)
        parity = Console.ReadLine()

        If parity = "" Then
            parity = defaultPortParity.ToString()
        End If

        Return CType([Enum].Parse(GetType(Parity), parity, True), Parity)
    End Function
    ' Display DataBits values and prompt user to enter a value.
    Public Shared Function SetPortDataBits(defaultPortDataBits As Integer) As Integer
        Dim dataBits As String

        Console.Write("Enter DataBits value (Default: {0}): ", defaultPortDataBits)
        dataBits = Console.ReadLine()

        If dataBits = "" Then
            dataBits = defaultPortDataBits.ToString()
        End If

        Return Integer.Parse(dataBits.ToUpperInvariant())
    End Function
    ' Display StopBits values and prompt user to enter a value.

    Public Shared Function SetPortStopBits(defaultPortStopBits As StopBits) As StopBits
        Dim stopBits As String

        Console.WriteLine("Available StopBits options:")
        For Each s As String In [Enum].GetNames(GetType(StopBits))
            Console.WriteLine("   {0}", s)
        Next

        Console.Write("Enter StopBits value (None is not supported and " &
                      vbLf & "raises an ArgumentOutOfRangeException. " &
                      vbLf & " (Default: {0}):", defaultPortStopBits.ToString())
        stopBits = Console.ReadLine()

        If stopBits = "" Then
            stopBits = defaultPortStopBits.ToString()
        End If

        Return CType([Enum].Parse(GetType(StopBits), stopBits, True), StopBits)
    End Function
    Public Shared Function SetPortHandshake(defaultPortHandshake As Handshake) As Handshake
        Dim handshake As String

        Console.WriteLine("Available Handshake options:")
        For Each s As String In [Enum].GetNames(GetType(Handshake))
            Console.WriteLine("   {0}", s)
        Next

        Console.Write("Enter Handshake value (Default: {0}):", defaultPortHandshake.ToString())
        handshake = Console.ReadLine()

        If handshake = "" Then
            handshake = defaultPortHandshake.ToString()
        End If

        Return CType([Enum].Parse(GetType(Handshake), handshake, True), Handshake)
    End Function
End Class

Commenti

Usare questa classe per controllare una risorsa del file di porta seriale. Questa classe fornisce le I/O sincrone e guidate dagli eventi, l'accesso agli stati di aggiunta e interruzione e l'accesso alle proprietà del driver seriale. Inoltre, la funzionalità di questa classe può essere sottoposta a wrapping in un oggetto interno Stream , accessibile tramite la BaseStream proprietà e passata alle classi che eseziona o usano flussi.

La SerialPort classe supporta le codifiche seguenti: ASCIIEncoding, UTF8Encoding, UnicodeEncoding, UTF32Encodinge qualsiasi codifica definita in mscorlib.dll in cui la tabella codici è minore di 50000 o la tabella codici è 54936. È possibile usare codifiche alternative, ma è necessario usare il ReadByte metodo o Write ed eseguire manualmente la codifica.

Utilizzare il GetPortNames metodo per recuperare le porte valide per il computer corrente.

Se un SerialPort oggetto viene bloccato durante un'operazione di lettura, non interrompere il thread. Chiudere invece il flusso di base o eliminare l'oggetto SerialPort .