www.pudn.com > OracleServiceManager.zip > ServiceState.cs

using System; 
using System.Diagnostics; 
using System.ServiceProcess; 
 
namespace kae.ServiceStatePublisher 
{ 
	/// 
 
	/// Defines an interface for encapsulating the behavior associated with a particular state of the Context. 
	/// 
 
	///  
	/// ServiceState is implemented as an abstract class, rather than an interface.  This choice provides valuable assistance supporting default behavior. 
	/// Since the class is abstract, a client cannot use this class on its own.  
	/// For more information on the state pattern see Design Patterns: Elements of Reusable Code by Gamma, et al. 
	///  
	public abstract class ServiceState 
	{ 
		private const string SSP_SOURCE = "ServiceStatePublisher"; 
		private const string SSP_EVENTLOG = "Application"; 
 
		public ServiceState() { } 
 
		public virtual void Start( ServiceContext context) { } 
		public virtual void Stop( ServiceContext context) { } 
		public virtual void Pause( ServiceContext context) { } 
		public virtual void Continue( ServiceContext context) { } 
 
		protected void ChangeState( ServiceContext context, ServiceState state) 
		{ 
			context.State = state; 
		} 
 
		public override string ToString() 
		{ 
			return String.Empty; 
		} 
 
		public virtual string Status 
		{ 
			get { return String.Empty; } 
		} 
 
		public virtual bool IsRunning 
		{ 
			get { return false; } 
		} 
 
		public virtual bool IsStopped 
		{ 
			get { return false; } 
		} 
 
		public virtual bool IsPaused 
		{ 
			get { return false; } 
		} 
 
		public virtual bool IsChanging 
		{ 
			get { return false; } 
		} 
 
		public virtual bool CanStart( ServiceContext context) 
		{ 
			bool canStart = false; 
			if (context.Controller != null) 
				canStart = !(IsRunning | IsChanging); 
 
			return canStart; 
		} 
 
		public virtual bool CanPause( ServiceContext context) 
		{ 
			bool canPause = false; 
			if (context.Controller != null && context.Controller.CanPauseAndContinue) 
				canPause = !(IsPaused | IsChanging); 
 
			return canPause; 
		} 
 
		public virtual bool CanStop( ServiceContext context) 
		{ 
			bool canStop = false; 
			if (context.Controller != null) 
				canStop = !(IsStopped | IsChanging); 
 
			return canStop; 
		} 
 
		protected virtual void LogError( string message, EventLogEntryType entryType) 
		{ 
			if (!EventLog.SourceExists( SSP_SOURCE)) 
				EventLog.CreateEventSource( SSP_SOURCE, SSP_EVENTLOG); 
 
			EventLog sspLog = new EventLog(); 
			sspLog.Source = SSP_SOURCE; 
 
			sspLog.WriteEntry( message, entryType); 
 
			sspLog.Close(); 
		} 
	} 
}