TraceEvent Event

In This Topic

Occurs when DbMonitor object signals about some database activity.

Syntax

Visual Basic
C#

'Declaration
 
Public Event TraceEvent As MonitorEventHandler

public event MonitorEventHandler TraceEvent

Event Data

The event handler receives an argument of type MonitorEventArgs containing data related to this event. The following MonitorEventArgs properties provide information specific to this event.

Property	Description
CallStack	Gets the call stack of the monitor event.
Description	Gets the description of a DbMonitor event.
Duration	The time between the start and the end of the event.
EventType	Gets DbMonitor event type.
ExtraInfo	Gets the additional information for a DbMonitor event.
TracePoint	Determines whether TraceEvent event occurs before or after the operation takes place.

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)
{
        UniConnection myConn = new UniConnection(
                "Provider=MySQL;User Id=root;Host=localhost;Database=Test"
        );
        UniMonitor myMonitor = new UniMonitor();
        myMonitor.TraceEvent += new MonitorEventHandler(OnEvent);
        myMonitor.IsActive = true;
        UniCommand myCommand = new UniCommand("select count(*) from dept",myConn);
        myConn.Open();
        Console.WriteLine(myCommand.ExecuteScalar());
        myConn.Close();
        myMonitor.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 myConn As UniConnection = New UniConnection( _
                "Provider=MySQL;User Id=root;Host=localhost;Database=Test" _
        )
        Dim myMonitor As UniMonitor = New UniMonitor
        AddHandler myMonitor.TraceEvent, AddressOf OnEvent
        myMonitor.IsActive = True
        Dim myCommand As UniCommand = New UniCommand("select count(*) from dept", myConn)
        myConn.Open()
        Console.WriteLine(myCommand.ExecuteScalar())
        myConn.Close()
        RemoveHandler myMonitor.TraceEvent, AddressOf OnEvent
        Console.ReadLine()
End Sub

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

DbMonitor Class
DbMonitor Members

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