MonitorEventHandler Delegate

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Represents the method that will handle the TraceEvent event of the DbMonitor class.

Syntax

Visual Basic
C#


'Declaration Public Delegate Sub MonitorEventHandler( _ ByVal sender As Object, _ ByVal e As MonitorEventArgs _ )


public delegate void MonitorEventHandler( object sender, MonitorEventArgs e )

Parameters

sender: The source of the event.
e: The MonitorEventArgs object that contains the event data.

Remarks

When you create a MonitorEventArgs delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see "Events and Delegates" in the .NET Framework SDK documentation.

Example

The following sample shows how to enable and disable monitoring of database activity in your application.

csharp


static void OnEvent(object sender, MonitorEventArgs e) { if (e.TracePoint==MonitorTracePoint.BeforeEvent) { Console.WriteLine("Description: " + e.Description); Console.WriteLine(" Extra info: " + e.ExtraInfo); } } [MTAThread] static void Main(string[] args) { MongoDBConnection mongoDBConn = new MongoDBConnection( "Host=localhost;Port=27017;Database=sample;User Id=user;Password=pwd;"); MongoDBMonitor mongoDBMonitor = new MongoDBMonitor(); mongoDBMonitor.TraceEvent += new MonitorEventHandler(OnEvent); mongoDBMonitor.IsActive = true; MongoDBCommand mongoDBCommand = new MongoDBCommand("select count(*) from emp",mongoDBConn); mongoDBConn.Open(); Console.WriteLine(mongoDBCommand.ExecuteScalar()); mongoDBConn.Close(); mongoDBMonitor.TraceEvent -= new MonitorEventHandler(OnEvent); Console.ReadLine(); }

static void OnEvent(object sender, MonitorEventArgs e)
{
  if (e.TracePoint==MonitorTracePoint.BeforeEvent)
  {
    Console.WriteLine("Description: " + e.Description);
    Console.WriteLine(" Extra info: " + e.ExtraInfo);
  }
}


[MTAThread]
static void Main(string[] args)
{
  MongoDBConnection mongoDBConn = new MongoDBConnection(
      "Host=localhost;Port=27017;Database=sample;User Id=user;Password=pwd;");
  MongoDBMonitor mongoDBMonitor = new MongoDBMonitor();
  mongoDBMonitor.TraceEvent += new MonitorEventHandler(OnEvent);
  mongoDBMonitor.IsActive = true;
  MongoDBCommand mongoDBCommand = new MongoDBCommand("select count(*) from emp",mongoDBConn);
  mongoDBConn.Open();
  Console.WriteLine(mongoDBCommand.ExecuteScalar());
  mongoDBConn.Close();
  mongoDBMonitor.TraceEvent -= new MonitorEventHandler(OnEvent);
  Console.ReadLine();
}

Visual Basic


Sub OnEvent(ByVal sender As Object, ByVal e As MonitorEventArgs) If e.TracePoint = MonitorTracePoint.BeforeEvent Then Console.WriteLine("Description: " & e.Description) Console.WriteLine(" Extra info: " & e.ExtraInfo) End If End Sub <MTAThread()> _ Sub Main() Dim mongoDBConn As MongoDBConnection = New MongoDBConnection( _ "Host=localhost;Port=27017;Database=sample;User Id=user;Password=pwd;") Dim mongoDBMonitor As MongoDBMonitor = New MongoDBMonitor AddHandler mongoDBMonitor.TraceEvent, AddressOf OnEvent mongoDBMonitor.IsActive = True Dim mongoDBCommand As MongoDBCommand = New MongoDBCommand("select count(*) from emp", mongoDBConn) mongoDBConn.Open() Console.WriteLine(mongoDBCommand.ExecuteScalar()) mongoDBConn.Close() RemoveHandler mongoDBMonitor.TraceEvent, AddressOf OnEvent Console.ReadLine() End Sub

Sub OnEvent(ByVal sender As Object, ByVal e As MonitorEventArgs)
  If e.TracePoint = MonitorTracePoint.BeforeEvent Then
    Console.WriteLine("Description: " & e.Description)
    Console.WriteLine(" Extra info: " & e.ExtraInfo)
  End If
End Sub

<MTAThread()> _
Sub Main()
  Dim mongoDBConn As MongoDBConnection = New MongoDBConnection( _
      "Host=localhost;Port=27017;Database=sample;User Id=user;Password=pwd;")
  Dim mongoDBMonitor As MongoDBMonitor = New MongoDBMonitor
  AddHandler mongoDBMonitor.TraceEvent, AddressOf OnEvent
  mongoDBMonitor.IsActive = True
  Dim mongoDBCommand As MongoDBCommand = New MongoDBCommand("select count(*) from emp", mongoDBConn)
  mongoDBConn.Open()
  Console.WriteLine(mongoDBCommand.ExecuteScalar())
  mongoDBConn.Close()
  RemoveHandler mongoDBMonitor.TraceEvent, AddressOf OnEvent
  Console.ReadLine()
End Sub

Reference

MonitorEventHandler Members
Devart.Common Namespace

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