Many of us have implemented logging in our ASP.NET, Windows Forms and WPF applications, so why shouldn’t you do the same in your Silverlight applications? Well, you should. In this blog post I will show you one approach on how you might perform this logging. The class I will use is called PDSALoggingManager. This class has a method named Log() you use to publish data into a log file in your Silverlight application. A method named LogException() is also available for logging information about any exceptions that happen on the client-side of your Silverlight application. Let’s take a look at the usage of the PDSALoggingManager class.
Logging Data
The simplest way to log information using the PDSALoggingManager class is to call the Log() method with some string data as shown below:
PDSALoggingManager.Instance.Log("Some data to log");
This will add the string passed to the Log() method to an internal StringBuilder object that contains the log information followed by a NewLine character. The Log() method also writes the string to a file located in isolated storage. What is written for each piece of data passed to the Log() method is shown here:
'Informational' log entry written on 5/22/2012 5:51:48 AM, from class: 'SL_Log.MainPage'
Some Data To Log
If you set the LogSystemInfo property on the PDSALoggingManager class prior to calling Log(), then system information is written to the log at the same time as the log data. Below is a sample of the log data with the system information appended to the end.
---------------------------------------------------------
'Informational' log entry written on 5/22/2012 5:51:48 AM, from class: 'SL_Log.MainPage'
Some Data To Log
System Information
DateTime=5/22/2012 5:51:48 AM
Current URL=file:///D:/MyStuff/BlogEntries/2012/
Samples/SL-Log/SL-Log/Bin/Debug/SL_LogTestPage.html
OSVersion=Microsoft Windows NT 6.1.7601 Service Pack 1
OSName=Windows 7
CurrentAssemblyName=PDSA.Silverlight, Version=5.0.0.0,
Culture=neutral, PublicKeyToken=null
MainAssemblyName=SL-Log, Version=1.0.0.0, Culture=neutral,
PublicKeyToken=null
AppDomainName=Silverlight AppDomain
UserLanguage=en-US
CompanyName=PDSA, Inc.
ProductName=Silverlight Logging
Description=Silverlight Logging
Title=Silverlight Logging
Copyright=Copyright © 2012 by PDSA, Inc.
ApplicationVersion=1.0.0.0
Stack Trace={LogInfoSample,btnLogInfo_Click}
-----------------------------------------------------------
The system information added to the end of the log comes from another class called PDSASystemInfo. Note that I blogged about this class earlier, so check out my previous blog entry at http://weblogs.asp.net/psheriff/archive/2012/05/20/retrieve-system-information-in-silverlight.aspx for information on this class and how that data was gathered.
Passing Extra Data to Log
You have an additional overload on the Log() method that takes a generic Dictionary<string, string> object you load with key/value pairs of data. Call this version of Log() like the following:
Dictionary<string, string> extra =
new Dictionary<string, string>();
extra.Add("CustomerId", "1");
extra.Add("StateCode", "CA");
PDSALoggingManager.Instance.Log("Some data to log", extra);
Read more: Paul Sheriff's Blog for the Real World
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