Customizing asp.net exception Logging - Part 76

Suggested Videos
Part 73 - Logging exceptions to the windows eventviewer
Part 74 - Logging exceptions as information entry type in windows eventviewer
Part 75 - Logging exceptions to database

In this video we will discuss about logging exception to both
1. A database table
2. Windows eventviewer

The ability to log exceptions must be configurable in web.config



Add a key to web.config file using appsettings element. This key determines, where the exceptions are logged.
<appSettings>
  <!--LogProvider = Database|EventViewer|Both-->
  <add key="LogProvider" value="Both"/>
</appSettings>

The "Logger" class reads the "LogProvider" key from web.config and logs the exceptions accordingly.



public class Logger
{
    public static void Log(Exception exception)
    {
        StringBuilder sbExceptionMessage = new StringBuilder();

        do
        {
            sbExceptionMessage.Append("Exception Type" + Environment.NewLine);
            sbExceptionMessage.Append(exception.GetType().Name);
            sbExceptionMessage.Append(Environment.NewLine + Environment.NewLine);
            sbExceptionMessage.Append("Message" + Environment.NewLine);
            sbExceptionMessage.Append(exception.Message + Environment NewLine + Environment.NewLine);
            sbExceptionMessage.Append("Stack Trace" + Environment.NewLine);
            sbExceptionMessage.Append(exception.StackTrace + Environment NewLine + Environment.NewLine);

            exception = exception.InnerException;
        }
        while (exception != null);

        string logProvider = ConfigurationManager.AppSettings["LogProvider"];
        if (logProvider.ToLower() == "both")
        {
            LogToDB(sbExceptionMessage.ToString());
            LogToEventViewer(sbExceptionMessage.ToString());
        }
        else if (logProvider.ToLower() == "database")
        {
            LogToDB(sbExceptionMessage.ToString());
        }
        else if (logProvider.ToLower() == "eventviewer")
        {
            LogToEventViewer(sbExceptionMessage.ToString());
        }
    }

    private static void LogToDB(string log)
    {
        // ConfigurationManager class is in System.Configuration namespace
        string connectionString = ConfigurationManager.ConnectionStrings["DBConnectionString"].ConnectionString;
        // SqlConnection is in System.Data.SqlClient namespace
        using (SqlConnection con = new SqlConnection(connectionString))
        {
            SqlCommand cmd = new SqlCommand("spInsertLog", con);
            // CommandType is in System.Data namespace
            cmd.CommandType = CommandType.StoredProcedure;

            SqlParameter parameter = new SqlParameter("@ExceptionMessage", log);
            cmd.Parameters.Add(parameter);

            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }

    private static void LogToEventViewer(string log)
    {
        if (EventLog.SourceExists("PragimTech.com"))
        {
            // Create an instance of the eventlog
            EventLog eventLog = new EventLog("PragimTech");
            // set the source for the eventlog
            eventLog.Source = "PragimTech.com";
            // Write the exception details to the event log as an error
            eventLog.WriteEntry(log, EventLogEntryType.Error);
        }
    }
}

Global.asax, Errors.aspx and WebForm1.aspx HTML and code have not changed from Part 75 - Logging exception to database.