WCF 项目应用连载[8]

因为ORM的原因，对Attribute编程有一种情节。。所以这节的出现，完全是因为在WCF对自定义Attribute的一种应用。

WCF 项目应用连载[7] - 绑定、服务、行为 大数据传输与限流 - 上

前面一节已经讲得差不多够了。

对WCF的限流，这节，提供一个类。ServiceThrottlingAttribute

让你以硬编码方式使用WCF服务限流

    [ServiceThrottling(50,200,100)]
    [ServiceContract(CallbackContract = typeof(ILigAgentCallback))]
    public interface ILigAgent

public class ServiceThrottlingAttribute : Attribute,IServiceBehavior
    {
        #region Constructors
        public ServiceThrottlingAttribute()
            : this(defaultCalls, defaultInstances, defaultSession)
        {
        }

        public ServiceThrottlingAttribute(int maxCalls, int maxInstances, int maxSessions)
        {
            this.Initialize(maxCalls, maxInstances, maxSessions);
        }
        #endregion

        #region Interfaces
        /// <summary>
        /// 
        /// </summary>
        /// <param name="serviceDescriptiong"></param>
        /// <param name="serviceHostBase"></param>
        /// <param name="endpoints"></param>
        /// <param name="bindingParameters"></param>
        void IServiceBehavior.AddBindingParameters(ServiceDescription serviceDescriptiong, ServiceHostBase serviceHostBase,
            Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
        {
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="serviceDescription"></param>
        /// <param name="serviceHostBase"></param>
        void IServiceBehavior.ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
        {
            ServiceThrottlingBehavior tbehavior = serviceDescription.Behaviors.Find<ServiceThrottlingBehavior>();
            if (tbehavior == null)
            {
                serviceDescription.Behaviors.Add(this.throttlingBehavior);
            }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="serviceDescription"></param>
        /// <param name="serviceHostBase"></param>
        void IServiceBehavior.Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
        {

        }
        #endregion

        #region Private Helpers
        private void Initialize(int maxCalls, int maxInstances, int maxSessions)
        {
            this.throttlingBehavior = new ServiceThrottlingBehavior();
            this.throttlingBehavior.MaxConcurrentCalls = maxCalls;
            this.throttlingBehavior.MaxConcurrentInstances = maxInstances;
            this.throttlingBehavior.MaxConcurrentSessions = maxSessions;
        }
        #endregion

        #region Fields
        private const int defaultThrottling = 50;
        private const int defaultCalls = 50;
        private const int defaultInstances = 200;
        private const int defaultSession = 100;
        private ServiceThrottlingBehavior throttlingBehavior = null;
        #endregion
    }