C# SerialPort 数据接收事件

Question

我正在监听串口 5 个字节的信息。轮询的完整答案需要 5 个字节。我的代码监听 serialport data_received 事件并检查 bytesToRead。有时，事件会触发并且 bytesToRead 为 0。事件不是只有在数据可用时才触发吗？

public SerialPort wheel = new SerialPort();
public void wheel_DataReceived(object sender, EventArgs e)
{
    if (wheel.BytesToRead < 5)
    {
        wheelRetry += 1;
        Log("Wheel Data Received: " + wheel.BytesToRead.ToString() + 
            " bytes. Need 5 bytes. Attempt #: " + wheelRetry.ToString());
    }

Answer 1

您可以设置 ReceivedBytesThreshold 属性:

var port = new SerialPort();
port.Open();    

//Only raise the event if 5 bytes have been received
port.ReceivedBytesThreshold = 5;

port.DataReceived += (s, e) =>
{
    //Handle the data
};

请注意，您应该在打开端口后挂接事件处理程序，
这是为了防止某些平台上的已知问题，该问题会阻止事件发生
如果它在端口打开之前被连接，则会引发。