Sukumar Raju's Blog

Here Exception Application block using Logging Application block to log excetpions to Application events.

Add Logging Handler

Right click Exception from context menu and choose New --> Logging Handler as shown below

Remember that a policy can have multiple exception types associated with it. Each exception type within the policy can have one or more exception handlers.

Step 3  Configuring Logging Handler

Here i have explained the logging application block category that will be used to log exceptions. You can configure the Logging Handler by selecting properties window on right hand as shown below.

Note that you can change the category name from General to something meaningful, especially if there will be many types of logging events within your application.

The next step is to choose the Formatter Type. Click the button next to Formatter Type and choose the formatter as shown below.

The output of the TextExceptionFormatter will be simple name-value pairs of data. The output of the XMLExceptionFromatter will contain XML data that is placed in Message section of Log file.

Note that important settings you configure are EventId, Title, LogCategory and Severity  as shown below.

That is it!!

You are ready to handle exceptions using best practice in consistent manner and log them using Logging application block.

Step 4  Logging Exceptions to application events

Here I have discussed how the exception is generated and logged to application events using Exception handling policy ‘MyPolicy’.

Logged exception in Application events

Running the above code logs an event to windows application events as shown below.

Step 5   Configuring application to log exceptions

The process of configuring this type of handler involves adding the exception handling application block to the configuration file, creating an exception policy, selecting an exception type, adding the logging handler and finally configuring the logging handler.

Step 5.1   Add Exception Handling Application block

Using the configuration tool by selecting application –> New option from context menu , add the exception handling application block as shown below.

Step 5.2   Adding Exception policy

After creating exception application block, next step is to create an exception policy. Right click the exception handling application block and select New Exception Policy from context menu as shown below.

The new exception policy is named as exception policy default. You can change the policy to your desired name by selecting Rename from context menu as shown below.

Step 5.3  Adding the Exception Type

Next step in configuration is adding the exception type for this exception policy to handle. To add Exception Type right click the Exception Policy node and choose New Exception Type. This opens a Type selector window as show in below picture, in which you can select a known class that inherits from System.Exception.

Alternatively, you can click the Load an Assembly button to select a custom assembly that contains exception classes. In this example Exception class is selected.

Step 5.4   Adding required Enterprise Library libraries and name spaces

The last part of the configuration is to make sure that you have added below out lined assemblies to your web application \bin folder and using the name spaces where ever you want to use application blocks.

The core Logging Application Block assembly:-

• Microsoft.Practices.EnterpriseLibrary.Logging.dll

Formats the exception and sends it to the Logging Application Block:-  

•   Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.dll

Namespaces

• using Microsoft.Practices.EnterpriseLibrary.ExceptionHandling;
• using Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging;
• using Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Configuration;
• using Microsoft.Practices.EnterpriseLibrary.Logging;

References:

http://msdn.microsoft.com/en-us/library/cc309212.aspx

http://www.codersource.net/csharp_exception_handling_enterprise_library.aspx

http://www.devx.com/dotnet/Article/35736