SerialPort::Close Method
Assembly: System (in System.dll)
| Exception | Condition |
|---|---|
| IOException | The port is in an invalid state. - or - An attempt to set the state of the underlying port failed. For example, the parameters passed from this SerialPort object were invalid. |
Calling this method closes the SerialPort object and clears both the receive and transmit buffers. This method calls the Component::Dispose() method, which invokes the protected SerialPort::Dispose(Boolean) method with the disposing parameter set to true.
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.
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. 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 ^) { } } }
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.