c# - 来自 Service.OnStart 的信号初始化失败

Question

我们有一个案例，在服务启动（OnStart）期间，启动了一个工作线程。工作线程连接到 SQL 数据库。如果数据库不可用，工作线程可以向主线程发出故障信号。问题是; 如何向服务控制管理器发出启动失败的信号。

Answer 1

这就是我们处理这种情况的方式。这段代码被添加到我们的主服务类中，然后在我们想要返回启动失败的地方，调用 SetServiceFail(1065)，然后从 OnStart 返回。在这种情况下 1065 返回数据库不存在状态。

我还要注意，在 SetServiceFail 中我对 serviceType 进行了硬编码，因为在我们的例子中，我们所有的服务都是独立的，所以我保持简单。

private void SetServiceFail (int ErrorCode)
{
     SERVICE_STATUS _ServiceStatus = new SERVICE_STATUS ();
     _ServiceStatus.currentState = (int) State.SERVICE_STOPPED;
     _ServiceStatus.serviceType = 16; //SERVICE_WIN32_OWN_PROCESS
     _ServiceStatus.waitHint = 0;
     _ServiceStatus.win32ExitCode = ErrorCode;
     _ServiceStatus.serviceSpecificExitCode = 0;
     _ServiceStatus.checkPoint = 0;
     _ServiceStatus.controlsAccepted = 0 |
           (this.CanStop ? (int) ControlsAccepted.ACCEPT_STOP : 0) |
           (this.CanShutdown ? (int) ControlsAccepted.ACCEPT_SHUTDOWN : 0) |
           (this.CanPauseAndContinue ? (int) ControlsAccepted.ACCEPT_PAUSE_CONTINUE : 0) |
           (this.CanHandleSessionChangeEvent ? (int) ControlsAccepted.ACCEPT_SESSION_CHANGE : 0) |
           (this.CanHandlePowerEvent ? (int) ControlsAccepted.ACCEPT_POWER_EVENT : 0);
     SetServiceStatus (this.ServiceHandle, ref _ServiceStatus);
}

public enum State
{
     SERVICE_STOPPED = 1,
     SERVICE_START_PENDING = 2,
     SERVICE_STOP_PENDING = 3,
     SERVICE_RUNNING = 4,
     SERVICE_CONTINUE_PENDING = 5,
     SERVICE_PAUSE_PENDING = 6,
     SERVICE_PAUSED = 7
}

public enum ControlsAccepted
{
     ACCEPT_STOP = 1,
     ACCEPT_PAUSE_CONTINUE = 2,
     ACCEPT_SHUTDOWN = 4,
     ACCEPT_POWER_EVENT = 64,
     ACCEPT_SESSION_CHANGE = 128
}

[StructLayout (LayoutKind.Sequential)]
private struct SERVICE_STATUS
{
     public int serviceType;
     public int currentState;
     public int controlsAccepted;
     public int win32ExitCode;
     public int serviceSpecificExitCode;
     public int checkPoint;
     public int waitHint;
}

[DllImport ("advapi32.dll")]
private static extern bool SetServiceStatus (IntPtr hServiceStatus, ref SERVICE_STATUS lpServiceStatus);

Answer 2

One way to stop it is to use the ServiceController, but you wont get any fancy message in the service control manager about an error or a failure to start.

var controller = new System.ServiceProcess.ServiceController("NameOfYourService");
controller.Stop();