SerialPort Class
Represents a serial port resource.
To browse the .NET Framework source code for this type, see the Reference Source.
Assembly: System (in System.dll)
System::MarshalByRefObject
System.ComponentModel::Component
System.IO.Ports::SerialPort
| Name | Description | |
|---|---|---|
![]() | SerialPort() | Initializes a new instance of the SerialPort class. |
![]() | SerialPort(IContainer^) | Initializes a new instance of the SerialPort class using the specified IContainer object. |
![]() | SerialPort(String^) | Initializes a new instance of the SerialPort class using the specified port name. |
![]() | SerialPort(String^, Int32) | Initializes a new instance of the SerialPort class using the specified port name and baud rate. |
![]() | SerialPort(String^, Int32, Parity) | Initializes a new instance of the SerialPort class using the specified port name, baud rate, and parity bit. |
![]() | SerialPort(String^, Int32, Parity, Int32) | Initializes a new instance of the SerialPort class using the specified port name, baud rate, parity bit, and data bits. |
![]() | SerialPort(String^, Int32, Parity, Int32, StopBits) | Initializes a new instance of the SerialPort class using the specified port name, baud rate, parity bit, data bits, and stop bit. |
| Name | Description | |
|---|---|---|
![]() | BaseStream | Gets the underlying Stream object for a SerialPort object. |
![]() | BaudRate | Gets or sets the serial baud rate. |
![]() | BreakState | Gets or sets the break signal state. |
![]() | BytesToRead | Gets the number of bytes of data in the receive buffer. |
![]() | BytesToWrite | Gets the number of bytes of data in the send buffer. |
![]() | CanRaiseEvents | Gets a value indicating whether the component can raise an event.(Inherited from Component.) |
![]() | CDHolding | Gets the state of the Carrier Detect line for the port. |
![]() | Container | Gets the IContainer that contains the Component.(Inherited from Component.) |
![]() | CtsHolding | Gets the state of the Clear-to-Send line. |
![]() | DataBits | Gets or sets the standard length of data bits per byte. |
![]() | DesignMode | |
![]() | DiscardNull | Gets or sets a value indicating whether null bytes are ignored when transmitted between the port and the receive buffer. |
![]() | DsrHolding | Gets the state of the Data Set Ready (DSR) signal. |
![]() | DtrEnable | Gets or sets a value that enables the Data Terminal Ready (DTR) signal during serial communication. |
![]() | Encoding | Gets or sets the byte encoding for pre- and post-transmission conversion of text. |
![]() | Events | |
![]() | Handshake | Gets or sets the handshaking protocol for serial port transmission of data using a value from Handshake. |
![]() | IsOpen | Gets a value indicating the open or closed status of the SerialPort object. |
![]() | NewLine | |
![]() | Parity | Gets or sets the parity-checking protocol. |
![]() | ParityReplace | Gets or sets the byte that replaces invalid bytes in a data stream when a parity error occurs. |
![]() | PortName | Gets or sets the port for communications, including but not limited to all available COM ports. |
![]() | ReadBufferSize | Gets or sets the size of the SerialPort input buffer. |
![]() | ReadTimeout | Gets or sets the number of milliseconds before a time-out occurs when a read operation does not finish. |
![]() | ReceivedBytesThreshold | Gets or sets the number of bytes in the internal input buffer before a DataReceived event occurs. |
![]() | RtsEnable | Gets or sets a value indicating whether the Request to Send (RTS) signal is enabled during serial communication. |
![]() | Site | |
![]() | StopBits | Gets or sets the standard number of stopbits per byte. |
![]() | WriteBufferSize | Gets or sets the size of the serial port output buffer. |
![]() | WriteTimeout | Gets or sets the number of milliseconds before a time-out occurs when a write operation does not finish. |
| Name | Description | |
|---|---|---|
![]() | Close() | |
![]() | CreateObjRef(Type^) | Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.(Inherited from MarshalByRefObject.) |
![]() | DiscardInBuffer() | Discards data from the serial driver's receive buffer. |
![]() | DiscardOutBuffer() | Discards data from the serial driver's transmit buffer. |
![]() | Dispose() | |
![]() | Dispose(Boolean) | Releases the unmanaged resources used by the SerialPort and optionally releases the managed resources.(Overrides Component::Dispose(Boolean).) |
![]() | Equals(Object^) | Determines whether the specified object is equal to the current object.(Inherited from Object.) |
![]() | Finalize() | |
![]() | GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
![]() | GetLifetimeService() | Retrieves the current lifetime service object that controls the lifetime policy for this instance.(Inherited from MarshalByRefObject.) |
![]() ![]() | GetPortNames() | Gets an array of serial port names for the current computer. |
![]() | GetService(Type^) | |
![]() | GetType() | |
![]() | InitializeLifetimeService() | Obtains a lifetime service object to control the lifetime policy for this instance.(Inherited from MarshalByRefObject.) |
![]() | MemberwiseClone() | |
![]() | MemberwiseClone(Boolean) | Creates a shallow copy of the current MarshalByRefObject object.(Inherited from MarshalByRefObject.) |
![]() | Open() | Opens a new serial port connection. |
![]() | Read(array<Byte>^, Int32, Int32) | Reads a number of bytes from the SerialPort input buffer and writes those bytes into a byte array at the specified offset. |
![]() | Read(array<Char>^, Int32, Int32) | Reads a number of characters from the SerialPort input buffer and writes them into an array of characters at a given offset. |
![]() | ReadByte() | Synchronously reads one byte from the SerialPort input buffer. |
![]() | ReadChar() | Synchronously reads one character from the SerialPort input buffer. |
![]() | ReadExisting() | Reads all immediately available bytes, based on the encoding, in both the stream and the input buffer of the SerialPort object. |
![]() | ReadLine() | Reads up to the NewLine value in the input buffer. |
![]() | ReadTo(String^) | Reads a string up to the specified value in the input buffer. |
![]() | ToString() | |
![]() | Write(array<Byte>^, Int32, Int32) | Writes a specified number of bytes to the serial port using data from a buffer. |
![]() | Write(array<Char>^, Int32, Int32) | Writes a specified number of characters to the serial port using data from a buffer. |
![]() | Write(String^) | Writes the specified string to the serial port. |
![]() | WriteLine(String^) | Writes the specified string and the NewLine value to the output buffer. |
| Name | Description | |
|---|---|---|
![]() ![]() | InfiniteTimeout | Indicates that no time-out should occur. |
| Name | Description | |
|---|---|---|
![]() | DataReceived | Indicates that data has been received through a port represented by the SerialPort object. |
![]() | Disposed | |
![]() | ErrorReceived | Indicates that an error has occurred with a port represented by a SerialPort object. |
![]() | PinChanged | Indicates that a non-data signal event has occurred on the port represented by the SerialPort object. |
Note |
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To view the .NET Framework source code for this type, see the Reference Source. You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions. |
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.
You use the GetPortNames method to retrieve the valid ports for the current computer.
If a SerialPort object becomes blocked during a read operation, do not abort the thread. Instead, either close the base stream or dispose of the SerialPort object.
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.
#using <System.dll> using namespace System; using namespace System::IO::Ports; using namespace System::Threading; public ref class PortChat { private: static bool _continue; static SerialPort^ _serialPort; 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 ^) { } } } static String^ SetPortName(String^ defaultPortName) { String^ portName; Console::WriteLine("Available Ports:"); for each (String^ s in SerialPort::GetPortNames()) { Console::WriteLine(" {0}", s); } Console::Write("Enter COM port value (Default: {0}): ", defaultPortName); portName = Console::ReadLine(); if (portName == "") { portName = defaultPortName; } return portName; } static Int32 SetPortBaudRate(Int32 defaultPortBaudRate) { String^ baudRate; Console::Write("Baud Rate(default:{0}): ", defaultPortBaudRate); baudRate = Console::ReadLine(); if (baudRate == "") { baudRate = defaultPortBaudRate.ToString(); } return Int32::Parse(baudRate); } static Parity SetPortParity(Parity defaultPortParity) { String^ parity; Console::WriteLine("Available Parity options:"); for each (String^ s in Enum::GetNames(Parity::typeid)) { Console::WriteLine(" {0}", s); } Console::Write("Enter Parity value (Default: {0}):", defaultPortParity.ToString()); parity = Console::ReadLine(); if (parity == "") { parity = defaultPortParity.ToString(); } return (Parity)Enum::Parse(Parity::typeid, parity); } static Int32 SetPortDataBits(Int32 defaultPortDataBits) { String^ dataBits; Console::Write("Enter DataBits value (Default: {0}): ", defaultPortDataBits); dataBits = Console::ReadLine(); if (dataBits == "") { dataBits = defaultPortDataBits.ToString(); } return Int32::Parse(dataBits); } static StopBits SetPortStopBits(StopBits defaultPortStopBits) { String^ stopBits; Console::WriteLine("Available Stop Bits options:"); for each (String^ s in Enum::GetNames(StopBits::typeid)) { 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(StopBits::typeid, stopBits); } static Handshake SetPortHandshake(Handshake defaultPortHandshake) { String^ handshake; Console::WriteLine("Available Handshake options:"); for each (String^ s in Enum::GetNames(Handshake::typeid)) { 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(Handshake::typeid, handshake); } }; int main() { PortChat::Main(); }
for the ability to call unmanaged code. Associated enumeration: UnmanagedCode
Available since 2.0
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.







