Events
Mar 17, 9 PM - Mar 21, 10 AM
Join the meetup series to build scalable AI solutions based on real-world use cases with fellow developers and experts.
Register nowThis browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
You can use the My.Application.Log
and My.Log
objects to log information about exceptions that occur in your application. These examples show how to use the My.Application.Log.WriteException
method to log exceptions that you catch explicitly and exceptions that are unhandled.
For logging tracing information, use the My.Application.Log.WriteEntry
method. For more information, see WriteEntry
Create the method that will generate the exception information.
Public Sub ExceptionLogTest(ByVal fileName As String)
End Sub
Use a Try...Catch
block to catch the exception.
Try
Catch ex As Exception
End Try
Put the code that could generate an exception in the Try
block.
Uncomment the Dim
and MsgBox
lines to cause a NullReferenceException exception.
' Code that might generate an exception goes here.
' For example:
' Dim x As Object
' MsgBox(x.ToString)
In the Catch
block, use the My.Application.Log.WriteException
method to write the exception information.
My.Application.Log.WriteException(ex,
TraceEventType.Error,
"Exception in ExceptionLogTest " &
"with argument " & fileName & ".")
The following example shows the complete code for logging a handled exception.
Public Sub ExceptionLogTest(ByVal fileName As String)
Try
' Code that might generate an exception goes here.
' For example:
' Dim x As Object
' MsgBox(x.ToString)
Catch ex As Exception
My.Application.Log.WriteException(ex,
TraceEventType.Error,
"Exception in ExceptionLogTest " &
"with argument " & fileName & ".")
End Try
End Sub
Have a project selected in Solution Explorer. On the Project menu, choose Properties.
Click the Application tab.
Click the View Application Events button to open the Code Editor.
This opens the ApplicationEvents.vb file.
Have the ApplicationEvents.vb file open in the Code Editor. On the General menu, choose MyApplication Events.
On the Declarations menu, choose UnhandledException.
The application raises the UnhandledException event before the main application runs.
Add the My.Application.Log.WriteException
method to the UnhandledException
event handler.
My.Application.Log.WriteException(e.Exception,
TraceEventType.Critical,
"Application shut down at " &
My.Computer.Clock.GmtTime.ToString)
The following example shows the complete code for logging an unhandled exception.
Private Sub MyApplication_UnhandledException(
ByVal sender As Object,
ByVal e As ApplicationServices.UnhandledExceptionEventArgs
) Handles Me.UnhandledException
My.Application.Log.WriteException(e.Exception,
TraceEventType.Critical,
"Application shut down at " &
My.Computer.Clock.GmtTime.ToString)
End Sub
.NET feedback
.NET is an open source project. Select a link to provide feedback:
Events
Mar 17, 9 PM - Mar 21, 10 AM
Join the meetup series to build scalable AI solutions based on real-world use cases with fellow developers and experts.
Register nowTraining
Module
Implement exception handling in C# console applications - Training
This module explores the use of exceptions and the exception handling process in C# console applications. Hands-on activities provide experience implementing exception handling patterns for various coding scenarios.