Question

我正在开发C＃应用程序。每当新的USB驱动器连接到PC时，我都必须触发一个事件。这是我现在的代码：

public class usbState
{
    public usbState()
    {

    }

    private void DeviceInsertedEvent(object sender, EventArrivedEventArgs e)
    {
        ManagementBaseObject instance = (ManagementBaseObject)e.NewEvent["TargetInstance"];
        foreach (var property in instance.Properties)
        {
            Console.WriteLine(property.Name + " = " + property.Value);
        }
    }

    private void DeviceRemovedEvent(object sender, EventArrivedEventArgs e)
    {
        ManagementBaseObject instance = (ManagementBaseObject)e.NewEvent["TargetInstance"];
        foreach (var property in instance.Properties)
        {
            Console.WriteLine(property.Name + " = " + property.Value);
        }
    }

    public void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
    {
        WqlEventQuery insertQuery = new WqlEventQuery("SELECT * FROM __InstanceCreationEvent WITHIN 2 WHERE TargetInstance ISA 'Win32_USBHub'");

        ManagementEventWatcher insertWatcher = new ManagementEventWatcher(insertQuery);
        insertWatcher.EventArrived += new EventArrivedEventHandler(DeviceInsertedEvent);
        insertWatcher.Start();

        WqlEventQuery removeQuery = new WqlEventQuery("SELECT * FROM __InstanceDeletionEvent WITHIN 2 WHERE TargetInstance ISA 'Win32_USBHub'");
        ManagementEventWatcher removeWatcher = new ManagementEventWatcher(removeQuery);
        removeWatcher.EventArrived += new EventArrivedEventHandler(DeviceRemovedEvent);
        removeWatcher.Start();

        // Do something while waiting for events
        System.Threading.Thread.Sleep(20000000);
    }

}
class Program
{
    static void Main(string[] args)
    {
        usbState usb = new usbState();


        BackgroundWorker bgwDriveDetector = new BackgroundWorker();
        bgwDriveDetector.DoWork += usb.backgroundWorker1_DoWork;
        bgwDriveDetector.RunWorkerAsync();
        bgwDriveDetector.WorkerReportsProgress = true;
        bgwDriveDetector.WorkerSupportsCancellation = true;

        // System.Threading.Thread.Sleep(100000);
        Console.ReadKey();

    }
}

此代码可以正常工作并提供连接的USB的属性，但是问题是它没有提供连接USB的端口。我如何获取连接USB的端口号。

Answer 1

我使用此方法返回端口的确切名称（COM1，COM2 ...），例如，您应提供设备的预期名称（arduino，Camra ...）以及以ms为单位的搜索超时：

private string GetCOMName(string sExpectedPortName, int iTimeOut)
    {
        Stopwatch sp = new Stopwatch(); sp.Start();
        string sPortName = "Unknown";
        bool isPortFound = false;
        while (sp.ElapsedMilliseconds < iTimeOut)
        {
            using (var searcher = new ManagementObjectSearcher("SELECT * FROM Win32_PnPEntity WHERE Caption like '%(COM%'"))
            {
                var portnames = SerialPort.GetPortNames();
                var ports = searcher.Get().Cast<ManagementBaseObject>().ToList().Select(p => p["Caption"].ToString());

                var portList = portnames.Select(n => n + " - " + ports.FirstOrDefault(s => s.Contains(n))).ToList();

                foreach (var port in portList)
                {
                  // Pass here the expected name of your port , for example (Arduino or Camera...)
                    if (port.Contains(sExpectedPortName))
                    {

                        var start = port.IndexOf("(") + 1;//add one to not include quote
                        var end = port.LastIndexOf(")") - start;
                        sPortName = port.Substring(start, end);

                        isPortFound = true;
                        break;
                    }
                }
                Thread.Sleep(1000);
            }
            // if the port is found then we go out from the whileloop
            if (true == isPortFound)
                break;
        }
        // return the result
        return sPortName;
    }

在C＃中获取新连接的USB设备的COM端口（串行端口）

1 个答案: