WF中的跟踪服务(3):使用SqlTrackingService跟踪规则

在坚持学习WF(22):跟踪规则这篇文章我们讲述了如何使用Trace来对规则进行跟踪，我们也可以使用SqlTrackingService跟踪规则，我们先来建立一个顺序型工作流程序，工作流设计器中我们只添加一个PolicyActivity活动，并设计他的RuleSet，我们还是使用坚持学习WF(22):跟踪规则这篇文章中的RuleSet，具体请看下表：

Rule	Conditon	ThenAction	ElseAction
RuleC	this.D < 100	this.B = this.B - 12 System.Console.WriteLine("RuleC:Then" + this.B)
RuleB	this.B > 50	this.C = "Preferred" System.Console.WriteLine("RuleB:Then" + this.C)	this.C = "Normal" System.Console.WriteLine("RuleB:Else" + this.C)
RuleA	this.A > 10	this.B = 60 System.Console.WriteLine("RuleA:Then" + this.B)	this.B = 40 System.Console.WriteLine("RuleA:Else" + this.B)

工作流代码中添加相关变量如下：
private intA = 12;
private intD = 99;
private intB = 0;
private stringC = "";

宿主程序中我们加载SqlTrackingService服务，代码如下：

namespace CarySqlRuleTracking
{
    class Program
    {
        private static String strConn = String.Format("Initial Catalog={0};Data Source={1};
           Integrated Security={2};", "WorkflowTracking", @"localhost\SQLEXPRESS", "SSPI");
        static void Main(string[] args)
        {
            using(WorkflowRuntime workflowRuntime = new WorkflowRuntime())
            {
                SqlTrackingService sts = new SqlTrackingService(strConn);
                AutoResetEvent waitHandle = new AutoResetEvent(false);
                workflowRuntime.WorkflowCompleted += delegate(object sender, 
                WorkflowCompletedEventArgs e) {waitHandle.Set();};
                workflowRuntime.WorkflowTerminated += delegate(object sender, 
                WorkflowTerminatedEventArgs e)
                {
                    Console.WriteLine(e.Exception.Message);
                    waitHandle.Set();
                };
                workflowRuntime.AddService(sts);
                
                WorkflowInstance instance = workflowRuntime.CreateWorkflow(typeof(
                CarySqlRuleTracking.CarySqlRuleTrackingWorkflow));
                Console.WriteLine("---工作流执行开始---");
                instance.Start();
                waitHandle.WaitOne();              
                Console.WriteLine("---工作流执行结束---");
                TrackingConsoleWriter trackingWriter = new TrackingConsoleWriter(strConn);
                trackingWriter.DisplayTrackingData(instance.InstanceId);
            }
        }
    }
}

这样跟踪数据就写入到跟踪数据库中了，我们还是使用WF中的跟踪服务(2):使用SqlTrackingService这篇文章中的
TrackingConsoleWriter类来将跟踪信息显示出来，代码如下：
TrackingConsoleWriter trackingWriter= new TrackingConsoleWriter(strConn);
trackingWriter.DisplayTrackingData(instance.InstanceId);

我们使用SqlTrackingQuery查询的时候。SqlTrackingWorkflowInstance有一个UserEvents属性，该属性包括UserTrackingRecord集合，每一个UserTrackingRecord都有一个UserData属性。如果这个UserTrackingRecord包含Rule数据的话，该UserData属性是一个RuleActionTrackingEvent对象的实例，该对象里包含RuleName和ConditionResult属性。当规则执行时，将发送 RuleActionTrackingEvent 对象作为用户跟踪点。在我们自己开发的TrackingConsoleWriter类中，下面的代码是处理这个的：
UserTrackingRecorduserRecord = record asUserTrackingRecord;
                  
if(userRecord.UserData isRuleActionTrackingEvent)
{
        WriteRuleData(userRecord);
}

private static void WriteRuleData(UserTrackingRecord userRecord)
{
    RuleActionTrackingEvent ruleAction = userRecord.UserData as RuleActionTrackingEvent;
    Console.WriteLine("{0:HH:mm:ss.fff} RuleAction from {1} Rule:{2} Result:{3}",
            userRecord.EventDateTime,userRecord.QualifiedName,
            ruleAction.RuleName,ruleAction.ConditionResult);
}

执行工作流结果如下：

上面的结果中包含RuleSet中各个规则的计算情况，下一篇文章中我们使用自定义跟踪配置文件来跟踪Rule中具体的变量的变化情况。