SerialPort.Close Método
Definição
public:
void Close();
public void Close ();
member this.Close : unit -> unit
Public Sub Close ()
Exceções
A porta está em um estado inválido.The port is in an invalid state.
- ou --or- Falha ao tentar definir o estado da porta subjacente.An attempt to set the state of the underlying port failed. Por exemplo, os parâmetros passados deste objeto SerialPort eram inválidos.For example, the parameters passed from this SerialPort object were invalid.
Exemplos
O exemplo de código a seguir demonstra o uso da SerialPort classe para permitir que dois usuários conversem de dois computadores separados conectados por um cabo de modem nulo.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. Neste exemplo, os usuários são solicitados a fornecer as configurações de porta e um nome de usuário antes de bater papo.In this example, the users are prompted for the port settings and a username before chatting. Este exemplo de código é parte de um exemplo de código maior fornecido para a SerialPort classe.This code example is part of a larger code example provided for the SerialPort class.
public:
static void Main()
{
String^ name;
String^ message;
StringComparer^ stringComparer = StringComparer::OrdinalIgnoreCase;
Thread^ readThread = gcnew Thread(gcnew ThreadStart(PortChat::Read));
// Create a new SerialPort object with default settings.
_serialPort = gcnew 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();
}
static void Read()
{
while (_continue)
{
try
{
String^ message = _serialPort->ReadLine();
Console::WriteLine(message);
}
catch (TimeoutException ^) { }
}
}
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 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
Comentários
Chamar esse método fecha o SerialPort objeto e limpa os buffers de recebimento e de transmissão.Calling this method closes the SerialPort object and clears both the receive and transmit buffers. Esse método chama o Component.Dispose() método, que invoca o método protegido SerialPort.Dispose(Boolean) com o disposing parâmetro definido como true .This method calls the Component.Dispose() method, which invokes the protected SerialPort.Dispose(Boolean) method with the disposing parameter set to true.
A prática recomendada para qualquer aplicativo é aguardar algum tempo depois de chamar o Close método antes de tentar chamar o Open método, pois a porta pode não ser fechada instantaneamente.The best practice for any application is to wait for some amount of time after calling the Close method before attempting to call the Open method, as the port may not be closed instantly.