Log File in an application made it in C#

In nearly all cases, use the class System.Diagnostics.EventLog:
http://msdn.microsoft.com/en-us/library/system.diagnostics.eventlog.aspx[^].

Please see also my past answer on log customization. This is not as trivial as it may seem:
How to create event log under a folder[^],
MsBuild OutPut to the TextBox on the fly in Windows Application[^].

As to the use of 3rd-party (Apache) open-source log4net (please see Solution 1), it also can be useful. Please see:
http://en.wikipedia.org/wiki/Log4net#Ports[^],
http://logging.apache.org/log4net/[^].

In most cases, there is no a need to use any 3rd-party or self-baked methods or frameworks.

—SA

public static class Logger
{
public static void Log(
string message)
{
File.AppendAllText(
“C:\\MyLogFile.txt” ,
DateTime.Now.
ToShortDateString() + ” ” +
DateTime.Now.
ToShortTimeString() + “:\t”
+ message + Environment.
NewLine);
}
}

static void Main( string[]
args)
{
Application.
ThreadException += new
System.Threading.
ThreadExceptionEventHandler(
Application_ThreadException
); //it must be before
Application.Run
…
Application.Run();
}
static void Application_
ThreadException( object
sender, System.Threading.
ThreadExceptionEventArgs e)
{
Logger.Log(e.Exception.
ToString());
}