SerialPort.DataReceived Event (System.IO.Ports)

Event Type

Examples

This example adds a SerialDataReceivedEventHandler to DataReceived to read all the available data received on the COM1 port. Note that to test this code it is necessary to have hardware attached to COM1 that will send data.

   #using <System.dll>
using namespace System;
using namespace System::IO::Ports;
ref class PortDataReceived
public:
    static void Main()
        SerialPort^ mySerialPort = gcnew SerialPort("COM1");
        mySerialPort->BaudRate = 9600;
        mySerialPort->Parity = Parity::None;
        mySerialPort->StopBits = StopBits::One;
        mySerialPort->DataBits = 8;
        mySerialPort->Handshake = Handshake::None;
        mySerialPort->RtsEnable = true;
        mySerialPort->DataReceived += gcnew SerialDataReceivedEventHandler(DataReceivedHandler);
        mySerialPort->Open();
        Console::WriteLine("Press any key to continue...");
        Console::WriteLine();
        Console::ReadKey();
        mySerialPort->Close();
private:
    static void DataReceivedHandler(
                        Object^ sender,
                        SerialDataReceivedEventArgs^ e)
        SerialPort^ sp = (SerialPort^)sender;
        String^ indata = sp->ReadExisting();
        Console::WriteLine("Data Received:");
        Console::Write(indata);
int main()
    PortDataReceived::Main();
   
    using System;
using System.IO.Ports;
class PortDataReceived
    public static void Main()
        SerialPort mySerialPort = new SerialPort("COM1");
        mySerialPort.BaudRate = 9600;
        mySerialPort.Parity = Parity.None;
        mySerialPort.StopBits = StopBits.One;
        mySerialPort.DataBits = 8;
        mySerialPort.Handshake = Handshake.None;
        mySerialPort.RtsEnable = true;
        mySerialPort.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandler);
        mySerialPort.Open();
        Console.WriteLine("Press any key to continue...");
        Console.WriteLine();
        Console.ReadKey();
        mySerialPort.Close();
    private static void DataReceivedHandler(
                        object sender,
                        SerialDataReceivedEventArgs e)
        SerialPort sp = (SerialPort)sender;
        string indata = sp.ReadExisting();
        Console.WriteLine("Data Received:");
        Console.Write(indata);
    
     Imports System.IO.Ports
Class PortDataReceived
    Public Shared Sub Main()
        Dim mySerialPort As New SerialPort("COM1")
        mySerialPort.BaudRate = 9600
        mySerialPort.Parity = Parity.None
        mySerialPort.StopBits = StopBits.One
        mySerialPort.DataBits = 8
        mySerialPort.Handshake = Handshake.None
        mySerialPort.RtsEnable = True
        AddHandler mySerialPort.DataReceived, AddressOf DataReceivedHandler
        mySerialPort.Open()
        Console.WriteLine("Press any key to continue...")
        Console.WriteLine()
        Console.ReadKey()
        mySerialPort.Close()
    End Sub
    Private Shared Sub DataReceivedHandler(
                        sender As Object,
                        e As SerialDataReceivedEventArgs)
        Dim sp As SerialPort = CType(sender, SerialPort)
        Dim indata As String = sp.ReadExisting()
        Console.WriteLine("Data Received:")
        Console.Write(indata)
    End Sub
End Class
     
      Remarks
     
     
      Data events can be caused by any of the items in the
      
       SerialData
      
      enumeration. Because the operating system determines whether to raise this event or not, not all parity errors may be reported.
     
     
      The
      
       DataReceived
      
      event is also raised if an Eof character is received, regardless of the number of bytes in the internal input buffer and the value of the
      
       ReceivedBytesThreshold
      
      property.
     
     
      
       PinChanged
      
      ,
      
       DataReceived
      
      , and
      
       ErrorReceived
      
      events may be called out of order, and there may be a slight delay between when the underlying stream reports the error and when the event handler is executed. Only one event handler can execute at a time.
     
     
      The
      
       DataReceived
      
      event is not guaranteed to be raised for every byte received. Use the
      
       BytesToRead
      
      property to determine how much data is left to be read in the buffer.
     
     
      The
      
       DataReceived
      
      event is raised on a secondary thread when data is received from the
      
       SerialPort
      
      object. Because this event is raised on a secondary thread, and not the main thread, attempting to modify some elements in the main thread, such as UI elements, could raise a threading exception. If it is necessary to modify elements in the main
      
       Form
      
      or
      
       Control
      
      , post change requests back using
      
       Invoke
      
      , which will do the work on the proper thread.
     
     
      For more information about handling events, see
      
       Handling and Raising Events
      
      .