重新连接VPN。视窗服务

Question

我一直在尝试实现一个可以保持 vpn 连接有效的 Windows 服务。我发现可以通过订阅RasConnectionWatcher.Disconnected 事件来使用DotRas 库：

public class SampleService {
    public SampleService() {
        this.shutdownEvent = new ManualResetEvent(false);
        this.connectionWatcher = new RasConnectionWatcher();
        this.connectionWatcher.Disconnected += onVpnDisconnected;
    }

    // redial
    void onVpnDisconnected(Object sender, RasConnectionEventArgs e) {
        this.DialUp();
    }

    void DialUp() {
        // connection setup is omitted
        // keep the handle of the connection
        this.connectionWatcher.Handle = dialer.Dial();
    }

    public void Start() {
        this.thread = new Thread(WorkerThreadFunc);
        this.thread.IsBackground = true;
        this.thread.Start();
    }

    public void Stop() {
        this.shutdownEvent.Set();
        if(!this.thread.Join(3000)) this.thread.Abort();
    }

    private void WorkerThreadFunc() {
        this.DialUp();
        while(!this.shutdownEvent.WaitOne(0)) Thread.Sleep(1000);
    }
}

当我启动服务时，vpn 连接打开没有任何问题，但是当我手动中断连接时，Disconnected 事件似乎没有启动。

Answer 1

解决方案 1

在这里找到类似的问题/答案：

http://social.msdn.microsoft.com/Forums/en-US/56ab2d0d-2425-4d76-81fc-04a1e1136141/ras-connection-application-and-service?forum=netfxnetcom.

解决方案 2

昨天得到了Jeff Winn的答复：

https://dotras.codeplex.com/discussions/547038

public class VpnKeeperService : IService {
    private ManualResetEvent shutdownEvent;
    private RasConnectionWatcher connWatcher;
    private Thread thread;

    public VpnKeeperService() {
        this.shutdownEvent = new ManualResetEvent(false);
        this.connWatcher = new RasConnectionWatcher();

        this.connWatcher.EnableRaisingEvents = true;
        this.connWatcher.Disconnected += (s, args) => { this.DialUp(); };
    }

    Boolean DialUp() {
        try {
            using(var phoneBook = new RasPhoneBook()) {
                var name = VpnConfig.GetConfig().ConnectionName;
                var user = VpnConfig.GetConfig().Username;
                var pass = VpnConfig.GetConfig().Password;
                var pbPath = VpnConfig.GetConfig().PhoneBookPath;

                phoneBook.Open(pbPath);

                var entry = phoneBook.Entries.FirstOrDefault(e => e.Name.Equals(name));
                if(entry != null) {
                    using(var dialer = new RasDialer()) {
                        dialer.EntryName = name;
                        dialer.Credentials = new NetworkCredential(user, pass);
                        dialer.PhoneBookPath = pbPath;

                        dialer.Dial();
                    }
                }
                else throw new ArgumentException(
                    message: "entry wasn't found: " + name,
                    paramName: "entry"
                );
            }
            return true;
        }
        catch {
            // log the exception
            return false;
        }
    }

    public void Start() {
        this.thread = new Thread(WorkerThreadFunc);
        this.thread.Name = "vpn keeper";
        this.thread.IsBackground = true;
        this.thread.Start();
    }

    public void Stop() {
        this.shutdownEvent.Set();
        if(!this.thread.Join(3000)) {
            this.thread.Abort();
        }
    }

    private void WorkerThreadFunc() {
        if(this.DialUp()) {
            while(!this.shutdownEvent.WaitOne(0)) {
                Thread.Sleep(1000);
            }
        }
    }
}

希望对某人有所帮助。