SerialPort.WriteLine Method (String)


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Writes the specified string and the NewLine value to the output buffer.

Namespace:   System.IO.Ports
Assembly:  System (in System.dll)

Public Sub WriteLine (
	text As String


Type: System.String

The string to write to the output buffer.

Exception Condition

The str parameter is null.


The specified port is not open.


The WriteLine method could not write to the stream.

If there are too many bytes in the input buffer and Handshake is set to XOnXOff then the SerialPort object may raise a TimeoutException while it waits for the device to be ready to accept more data.

The written output includes the NewLine string.

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. This code example is part of a larger code example provided for the SerialPort class.

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

    _continue = True

    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
            _serialPort.WriteLine([String].Format("<{0}>: {1}", name, message))
        End If
    End While

End Sub

Public Shared Sub Read()
    While _continue
            Dim message As String = _serialPort.ReadLine()
        Catch generatedExceptionName As TimeoutException
        End Try
    End While
End Sub

.NET Framework
Available since 2.0
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