How can I easily log a message to a file for debugging purposes?
Often, you need a way to monitor your applications once they are running on the server or even at the customer site -- away from your Visual Studio debugger. In those situations, it is often helpful to have a simple routine that you can use to log messages to a text file for later analysis.
Here’s a simple routine that has helped me a lot for example when writing server applications without an user interface:
using System.IO;
public string GetTempPath()
{
string path = System.Environment.GetEnvironmentVariable("TEMP");
if (!path.EndsWith("\\")) path += "\\";
return path;
}
public void LogMessageToFile(string msg)
{
System.IO.StreamWriter sw = System.IO.File.AppendText(
GetTempPath() + "My Log File.txt");
try
{
string logLine = System.String.Format(
"{0:G}: {1}.", System.DateTime.Now, msg);
sw.WriteLine(logLine);
}
finally
{
sw.Close();
}
}
With this simple method, all you need to do is to pass in a string like this:
LogMessageToFile("Hello, World");
The current date and time are automatically inserted to the log file along with your message.
[author: Jani Järvinen, C# MVP]
