c# - Managedwifi : Occasionally, WlanConnectionNotification 没有被解雇

Question

我有以下代码使用 managedWifi api (http://managedwifi.codeplex.com/) 监听 wifi 连接/断开事件

public void wlanConnectionChangeHandler(Wlan.WlanNotificationData notifyData, Wlan.WlanConnectionNotificationData connNotifyData){
        string msg = String.Empty;

        switch (notifyData.notificationSource)
        {
            case Wlan.WlanNotificationSource.ACM:

                switch ((Wlan.WlanNotificationCodeAcm)notifyData.notificationCode)
                {
                    case Wlan.WlanNotificationCodeAcm.ConnectionStart:
                        msg = "ConnectionStart";
                        break;

                    case Wlan.WlanNotificationCodeAcm.ConnectionComplete:
                            msg = "ConnectionComplete";
                            WlanClient client = new WlanClient();
                            foreach (WlanClient.WlanInterface wlanIface in client.Interfaces)
                            {
                                Wlan.WlanAssociationAttributes conAttributes = wlanIface.CurrentConnection.wlanAssociationAttributes;
                                Wlan.Dot11Ssid ssid = conAttributes.dot11Ssid;
                                PhysicalAddress bssid = conAttributes.Dot11Bssid;
                                int rssi = wlanIface.RSSI;

                                msg += ". ssid: " + GetStringForSSID(ssid) + ". rssi: " + rssi.ToString() + ". MAC: " + bssid.ToString();
                                break;
                            }

                        break;

                    case Wlan.WlanNotificationCodeAcm.Disconnecting:
                        msg = "Disconnecting";
                        break;

                    case Wlan.WlanNotificationCodeAcm.Disconnected:
                        msg = "Disconnected";
                        break;

                    default:
                        msg = "unknown notificationCode =" + notifyData.notificationCode;
                        break;

                }
                MessageBox.Show(msg + " for profile:" + connNotifyData.profileName);
                break;

            default:
                //MessageBox.Show("irrelevant notification. Ignore");
                break;
        }
    }

    static string GetStringForSSID(Wlan.Dot11Ssid ssid)
    {
        return Encoding.ASCII.GetString( ssid.SSID, 0, (int) ssid.SSIDLength );
    }

    private void registerWlanListener()
    {
        WlanClient client = new WlanClient();

        foreach (WlanClient.WlanInterface wlanIface in client.Interfaces)
        {
            string str = "Name=" + wlanIface.InterfaceName + ". State: ";

            switch (wlanIface.InterfaceState)
            {
                case Wlan.WlanInterfaceState.NotReady:
                    str += "NotReady";
                    break;

                case Wlan.WlanInterfaceState.Disconnected:
                    str += "Disconnected";
                    break;

                case Wlan.WlanInterfaceState.Disconnecting:
                    str += "Disconnecting";
                    break;

                case Wlan.WlanInterfaceState.Connected:
                    str += "Connected";
                    break;
            }

            wlanIface.WlanConnectionNotification += wlanConnectionChangeHandler;
            MessageBox.Show(str + ". Listener registered");
        }
    }

    private void unregisterWlanListener()
    {
        WlanClient client = new WlanClient();

        foreach (WlanClient.WlanInterface wlanIface in client.Interfaces)
        {
            wlanIface.WlanConnectionNotification -= wlanConnectionChangeHandler;
            MessageBox.Show(wlanIface.InterfaceName + ". Listener unregistered");
        }
    }

开始时，我调用了 registerWlanListener，在停止我的应用程序之前，我调用了 unregisterWlanListener()。我通过多次连接/断开 wifi 连接并尝试观察通知，在 win7 和 win8 平板电脑上测试了我的桌面应用程序。这些是两个平台上的问题:

1. 大多数时候，我的 wlanConnectionChangeHandler 在 wifi 连接/断开时被调用，一切正常。但是，在某些情况下，它根本不会被调用。什么会导致这种情况？我注意到在最初错过通知后，即使我继续连接/断开 wifi 连接，我也根本无法收到任何进一步的通知。

2. 在不同的情况下，即使我删除了事件处理程序，我仍然会收到通知。我在删除这些事件处理程序时遗漏了什么吗？

谢谢。

Answer 1

显然，我在编写代码时并没有想清楚。问题是我的 WlanClient 客户端的本地范围。通过将其设为全局变量并仅实例化一次来修复它。/捂脸