WriteEntry Method (My.Application.Log and My.Log)

Writes a message to the application's log listeners.

' Usage
My.Application.Log.WriteEntry(message)
My.Application.Log.WriteEntry(message ,severity)
My.Application.Log.WriteEntry(message ,severity ,id)
' Web usage
My.Log.WriteEntry(message)
My.Log.WriteEntry(message ,severity)
My.Log.WriteEntry(message ,severity ,id)
' Declaration
Public Sub WriteEntry( _
   ByVal message As String _
)
' -or-
Public Sub WriteEntry( _
   ByVal message As String, _
   ByVal severity As System.Diagnostics.TraceEventType _
)
' -or-
Public Sub WriteEntry( _
   ByVal message As String, _
   ByVal severity As System.Diagnostics.TraceEventType, _
   ByVal id As Integer _
)

Parameters

• message
  Required. The message to log. If message is Nothing, an empty string is used.

• severity
  The type of message. By default, TraceEventType.Information.

• id
  Message identifier, typically used for correlation. By default, related to entryType as described in the table.

Exceptions

The following conditions cause an exception:

• The exception or message type is Nothing (ArgumentNullException).

• The message type is not one of the TraceEventType enumeration values (InvalidEnumArgumentException).

• Code with partial trust calls the method, but writes to an event log listener that requires full trust (SecurityException).

Remarks

The WriteEntry method writes a message to the application's event log listeners.

In client applications, the Log object is available through the My.Application.Log object. In Web applications, the Log object is available through the My.Log object.

To learn which log listeners receive the WriteEntry method's messages, see Walkthrough: Determining Where My.Application.Log Writes Information. You can change default log listeners. For more information, see Working with Application Logs in Visual Basic.

For overloads that do not take the id argument, the id written to the log is defined by the following table.

severity	Default id
Information	0
Warning	1
Error	2
Critical	3
Start	4
Stop	5
Suspend	6
Resume	7
Verbose	8
Transfer	9

Tasks

The following table lists examples of tasks involving the WriteEntry method.

To	See
Write event information to the application's log listeners	How to: Write Log Messages
Determine where Log writes information	Walkthrough: Determining Where My.Application.Log Writes Information

Example

This example shows how to use the My.Application.Log.WriteEntry method to log tracing information. For more information, see How to: Write Log Messages.

Public Sub TracingTest(ByVal fileName As String)
    My.Application.Log.WriteEntry( _
        "Entering TracingTest with argument " & _
        fileName & ".")
    ' Code to trace goes here.
    My.Application.Log.WriteEntry( _
        "Exiting TracingTest with argument " & _
        fileName & ".")
End Sub

This code example can run only within a client application. Change My.Application.Log.WriteEntry to My.Log.WriteEntry for Web applications.

Requirements

Namespace:Microsoft.VisualBasic.Logging

Class:Log

Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)

Availability by Project Type

Project type	Available
Windows Application	Yes
Class Library	Yes
Console Application	Yes
Windows Control Library	Yes
Web Control Library	No
Windows Service	Yes
Web Site	Yes

Permissions

The following permission may be necessary:

Permission	Description
FileIOPermission	Controls the ability to access files and folders. Associated enumeration: Unrestricted.

For more information, see Code Access Security and Requesting Permissions.

See Also

Tasks

How to: Write Log Messages

Walkthrough: Determining Where My.Application.Log Writes Information

Concepts

Working with Application Logs in Visual Basic

Reference

My.Application.Log Object

My.Log Object

System.Diagnostics.TraceEventType

Log.WriteEntry