通过sendin AT命令检测调制解调器到不工作的串口列表

Question

我是c＃编程的新手，我在通过发送“AT”命令并接收响应并在UI上显示来检测调制解调器时遇到问题。该应用程序是在visual studio 2012桌面WPF应用程序中开发的.UI有两个列表一个用于列出可用的COM端口，另一个用于列出调制解调器响应及其相应的com端口。当我运行代码时，它只显示com端口，并且不显示响应形式的调制解调器。当我检查同一设备的响应时通过Hyperterminal，我能够收到“OK”的回复。我已经在下面发布了我的代码。请让我知道我做了哪些错误，以便我的代码可以运行。

CODE：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Data;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Imaging;

using System.Windows.Navigation;

using System.Windows.Shapes;


using System.Text.RegularExpressions;

using System.Management;

using Microsoft.Win32;

using System.Runtime.InteropServices;

using Microsoft.Win32.SafeHandles;

using System.Windows.Interop;

using System.IO.Ports;

using System.Threading;

using System.IO;

using System.Runtime.CompilerServices;

namespace WWU2

{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>

    public partial class MainWindow : Window

    {
        private const int WM_DEVICECHANGE = 0x0219;                 // device change event 
        private const int DBT_DEVICEARRIVAL = 0x8000;               // system detected a new device 
        private const int DBT_DEVICEREMOVEPENDING = 0x8003;         // about to remove, still available 
        private const int DBT_DEVICEREMOVECOMPLETE = 0x8004;        // device is gone 

        private const int DBT_DEVTYP_PORT = 0x00000003;             // serial, parallel 
        private SerialPort _serialPort;
        public MainWindow()
        {
            InitializeComponent();
            foreach (string s in SerialPort.GetPortNames())
            {

                List1.Items.Add(s);
                portcall(s);

            }
        }
        public async void portcall(String s)
        {
            await this.Dispatcher.InvokeAsync(() =>
                   {
                       communication(s);
                       Thread.Sleep(500);
                   });
        }
        public void communication(string s)
        {
            _serialPort = new SerialPort(s, 9600, Parity.None, 8, StopBits.One);
            _serialPort.Handshake = Handshake.RequestToSend;
            _serialPort.ReadTimeout = 500;
            _serialPort.WriteTimeout = 500;
            _serialPort.DtrEnable = true;
           // String input = "AT";
            _serialPort.DataReceived += new SerialDataReceivedEventHandler(sp_DataReceived);
            SendData();

        }
        private async void SendData()//string input)
        {
            String input = "AT";


            await this.Dispatcher.InvokeAsync(() =>
            {
                if (!_serialPort.IsOpen)
                {
                    try
                    {
                        _serialPort.Open();
                    }
                    catch { List1.Items.Add("cannot open comport"); }

                }

                _serialPort.Write(input);

            });
        }
        private async void sp_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            try
            {

                string data = _serialPort.ReadLine();

                // Invokes the delegate on the UI thread, and sends the data that was received to the invoked method.

                // ---- The "si_DataReceived" method will be executed on the UI thread which allows populating of the Listbox.

                await this.Dispatcher.InvokeAsync(() =>
                {
                    si_DataReceived(data);
                });
            }
            catch (Exception) { }//_serialPort[i].Close(); }
            // await Dispatcher.RunAsync(WindowStartupLocation.UI.CoreDispatcherPriority.High,()=> {this.List2.Items.Add(data.Trim())});
        }
        private void si_DataReceived(string data)
        {
            this.List2.Items.Add(data.Trim());
            this.List2.Items.Add(_serialPort.PortName.ToString());
            if (data.IndexOf("OK") > -1)
            {
                this.List2.Items.Add(data.Trim());
            }
            if (_serialPort.IsOpen)
            {
                _serialPort.DataReceived -= sp_DataReceived;
                _serialPort.Close();
                // _serialPort.Dispose();

            }
        }
    }
}