c# - 如何发现设备是否连接到特定的串行 (COM) 端口？

Question

如何使用 C# 的 SerialPort 类发现设备是否连接到特定的串行 (COM) 端口？

注意:即使没有设备连接到该端口，该类的Open 方法也会打开该端口。

Answer 1

1.WMI:SELECT * FROM Win32_SerialPort:

ManagementObjectSearcher manObjSearch = new ManagementObjectSearcher("Select * from Win32_SerialPort");
ManagementObjectCollection manObjReturn = manObjSearch.Get();

foreach (ManagementObject manObj in manObjReturn)
{
    //int s = manObj.Properties.Count;
    //foreach (PropertyData d in manObj.Properties)
    //{
    //    Console.WriteLine(d.Name);
    //}
    Console.WriteLine(manObj["DeviceID"].ToString());
    Console.WriteLine(manObj["Name"].ToString());
    Console.WriteLine(manObj["Caption"].ToString());
}

2. 如果设备发回响应:System.IO.Ports.SerialPort.GetPortNames()并发送基本命令:

foreach (string portname in SerialPort.GetPortNames())
{
    var sp = new SerialPort(portname, 4800, Parity.Odd, 8, StopBits.One);
    try
    {
        sp.Open();
        sp.Write("Your known command to device");
        Thread.Sleep(500);
        string received = sp.ReadLine();

        if (received == "expected response")
        {
            Console.WriteLine("device connected to: " + portname);
            break;
        }
    }
    catch (Exception)
    {
        Console.WriteLine("device NOT connected to: " + portname);
    }
    finally
    {
        sp.Close();
    }
}