SerialPort.DataReceived 事件

定義

命名空間:

System.IO.Ports

組件:

System.IO.Ports.dll

套件:

System.IO.Ports v8.0.0

來源:

SerialPort.cs

表示已從 SerialPort 物件所代表的連接埠上接收資料。

public:
 event System::IO::Ports::SerialDataReceivedEventHandler ^ DataReceived;

public event System.IO.Ports.SerialDataReceivedEventHandler DataReceived;

member this.DataReceived : System.IO.Ports.SerialDataReceivedEventHandler 

Public Custom Event DataReceived As SerialDataReceivedEventHandler 

事件類型

SerialDataReceivedEventHandler

範例

本範例會將 新增 SerialDataReceivedEventHandler 至 DataReceived ，以讀取 COM1 埠上接收的所有可用數據。 請注意，若要測試此程式碼，必須將硬體連結至將傳送數據的 COM1。

#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

備註

數據事件可能是由 列舉中的任何 SerialData 專案所造成。 因為操作系統會判斷是否要引發此事件，所以可能不會報告所有同位錯誤。

DataReceived如果收到 Eof 字元，不論內部輸入緩衝區中的位元組數目和屬性的值ReceivedBytesThreshold為何，也會引發事件。

PinChanged、 DataReceived和 ErrorReceived 事件可能會依序呼叫，而且基礎數據流報告錯誤時和執行事件處理程式時，可能會稍有延遲。 一次只能執行一個事件處理程式。

DataReceived事件不保證會針對收到的每個位元組引發。 BytesToRead使用 屬性來判斷緩衝區中要讀取的數據量。

DataReceived從 SerialPort 物件接收數據時，會在次要線程上引發事件。 因為這個事件是在次要線程上引發，而不是主線程，所以嘗試修改主線程中的某些元素，例如UI元素可能會引發線程例外狀況。 如果需要修改主要 Form 或 Control中的專案，請使用 將變更要求張貼回 Invoke，這會在適當的線程上執行工作。

如需處理事件的詳細資訊，請參閱 處理和引發事件。