Csharp/C Sharp/Development Class/Trace

demonstrates post-deployment tracing

<source lang="csharp"> /* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110

• /

1. define TRACE

/*

 Example21_13.cs demonstrates post-deployment tracing

• /

using System; using System.Globalization; using System.Diagnostics; public class Example21_13 {

 public static void Main() 
 {
   // Set up a switch to turn tracing on
   BooleanSwitch bsEnableTrace = new BooleanSwitch("TraceOutput", 
     "Turn on tracing");
   // Set up a TraceListener to a file
   TextWriterTraceListener tl = new TextWriterTraceListener("Example21_13.txt");
   Trace.Listeners.Add(tl);
   // And a second TraceListener to the event log
   EventLogTraceListener t2 = new EventLogTraceListener("Application");
   Trace.Listeners.Add(t2);
   Trace.WriteLineIf(bsEnableTrace.Enabled,"Starting Main()");
   // create a date and a currency value
   DateTime dtNow = DateTime.Now;
   Double curOriginal = 12345.67;
   // and format the variables for a specific culture
   CultureInfo ci = new CultureInfo("en-US");
   string sLocalizedDate = dtNow.ToString("d", ci);
   string sLocalizedCur = curOriginal.ToString("c", ci);
   if (bsEnableTrace.Enabled) 
   {
     Trace.Assert(sLocalizedDate != null, "Localized date has no content");
   }
   // print them out
   Console.WriteLine(sLocalizedDate);
   Console.WriteLine(sLocalizedCur);
   Trace.WriteLineIf(bsEnableTrace.Enabled, "Exiting Main()");
   Trace.Flush();
   Trace.Close();
 }

}

      </source>

demonstrates the use of TraceListener objects

<source lang="csharp"> /* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110

• /

1. define DEBUG

/*

 Example21_12.cs demonstrates the use of TraceListener objects

• /

using System; using System.Globalization; using System.Diagnostics; public class Example21_12 {

 public static void Main() 
 {
   // Set up a TraceListener to a file
   TextWriterTraceListener tl = new TextWriterTraceListener("Example21_12.txt");
   Debug.Listeners.Add(tl);
   // And a second TraceListener to the event log
   EventLogTraceListener t2 = new EventLogTraceListener("Application");
   Debug.Listeners.Add(t2);
   Debug.WriteLine("Starting Main()");
   // create a date and a currency value
   DateTime dtNow = DateTime.Now;
   Double curOriginal = 12345.67;
   // and format the variables for a specific culture
   CultureInfo ci = new CultureInfo("en-US");
   string sLocalizedDate = dtNow.ToString("d", ci);
   string sLocalizedCur = curOriginal.ToString("c", ci);
   Debug.Assert(sLocalizedDate != null, "Localized date has no content");
   // print them out
   Console.WriteLine(sLocalizedDate);
   Console.WriteLine(sLocalizedCur);
   Debug.WriteLine("Exiting Main()");
   Debug.Flush();
   Debug.Close();
 }

}

      </source>

Trace.WriteLine

<source lang="csharp">

using System; using System.Data; using System.Data.SqlClient; using System.Threading; using System.Diagnostics; class MainClass {

   static void Main() {
       Trace.WriteLine("Entered Main()");
       for (int i = 0; i < 6; i++)
           Trace.WriteLine(i);
       Trace.WriteLine("Exiting from Main()");
   }

}

</source>

Use Trace.Fail to alert a fail

<source lang="csharp">

using System; using System.Data; using System.Data.SqlClient; using System.Threading; using System.Diagnostics;

class Class1 {

   [STAThread]
   static void Main(string[] args) {
       SqlConnection dbConn = new SqlConnection("server=.;database=pubs;uid=sa;pwd=");
       SqlCommand dbComm = new SqlCommand("SELECT * FROM " + "authors", dbConn);
       SqlDataReader dr = null;
       Trace.WriteLine(DateTime.Now + " - Executing SQL statement");
       try {
           dbConn.Open();
           Trace.Assert(dbConn.State == ConnectionState.Open,"Error", "Connection failed...");
           dr = dbComm.ExecuteReader(CommandBehavior.CloseConnection);
           Trace.Assert(dr != null, "Error","The SqlDataReader is null!");
           while (dr.Read()) {
           }
       } catch {
           Trace.Fail("An error occurred in database access");
       } finally {
           if ((dr.IsClosed == false) && (dr != null))
               dr.Close();
       }
   }

}

</source>