[c#] How do I do logging in C# without using 3rd party libraries?

I would like to implement logging in my application, but would rather not use any outside frameworks like log4net.

So I would like to do something like DOS's echo to a file. What is the most effective way to do it?

Is there a way to log unhandled exceptions logged without using an outside framework?

This question is related to c# .net winforms performance logging

The answer is

If you want your own custom Error Logging you can easily write your own code. I'll give you a snippet from one of my projects.

public void SaveLogFile(object method, Exception exception)
    string location = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + @"\FolderName\";
        //Opens a new file stream which allows asynchronous reading and writing
        using (StreamWriter sw = new StreamWriter(new FileStream(location + @"log.txt", FileMode.Append, FileAccess.Write, FileShare.ReadWrite)))
            //Writes the method name with the exception and writes the exception underneath
            sw.WriteLine(String.Format("{0} ({1}) - Method: {2}", DateTime.Now.ToShortDateString(), DateTime.Now.ToShortTimeString(), method.ToString()));
            sw.WriteLine(exception.ToString()); sw.WriteLine("");
    catch (IOException)
        if (!File.Exists(location + @"log.txt"))
            File.Create(location + @"log.txt");

Then to actually write to the error log just write (q being the caught exception)

SaveLogFile(MethodBase.GetCurrentMethod(), `q`);

If you are looking for a real simple way to log, you can use this one liner. If the file doesn't exist, it's created.

System.IO.File.AppendAllText(@"c:\log.txt", "mymsg\n");

I would rather not use any outside frameworks like log4j.net.

Why? Log4net would probably address most of your requirements. For example check this class: RollingFileAppender.

Log4net is well documented and there are thousand of resources and use cases on the web.

I used to write my own error logging until I discovered ELMAH. I've never been able to get the emailing part down quite as perfectly as ELMAH does.

You can write directly to an event log. Check the following links:

And here's the sample from MSDN:

using System;
using System.Diagnostics;
using System.Threading;

class MySample{

    public static void Main(){

        // Create the source, if it does not already exist.
             //An event log source should not be created and immediately used.
             //There is a latency time to enable the source, it should be created
             //prior to executing the application that uses the source.
             //Execute this sample a second time to use the new source.
            EventLog.CreateEventSource("MySource", "MyNewLog");
            Console.WriteLine("Exiting, execute the application a second time to use the source.");
            // The source is created.  Exit the application to allow it to be registered.

        // Create an EventLog instance and assign its source.
        EventLog myLog = new EventLog();
        myLog.Source = "MySource";

        // Write an informational entry to the event log.    
        myLog.WriteEntry("Writing to event log.");


If you want to stay close to .NET check out Enterprise Library Logging Application Block. Look here. Or for a quickstart tutorial check this. I have used the Validation application Block from the Enterprise Library and it really suits my needs and is very easy to "inherit" (install it and refrence it!) in your project.

Examples related to c#

How can I convert this one line of ActionScript to C#? Microsoft Advertising SDK doesn't deliverer ads How to use a global array in C#? How to correctly write async method? C# - insert values from file into two arrays Uploading into folder in FTP? Are these methods thread safe? dotnet ef not found in .NET Core 3 HTTP Error 500.30 - ANCM In-Process Start Failure Best way to "push" into C# array

Examples related to .net

You must add a reference to assembly 'netstandard, Version= How to use Bootstrap 4 in ASP.NET Core No authenticationScheme was specified, and there was no DefaultChallengeScheme found with default authentification and custom authorization .net Core 2.0 - Package was restored using .NetFramework 4.6.1 instead of target framework .netCore 2.0. The package may not be fully compatible Update .NET web service to use TLS 1.2 EF Core add-migration Build Failed What is the difference between .NET Core and .NET Standard Class Library project types? Visual Studio 2017 - Could not load file or assembly 'System.Runtime, Version=' or one of its dependencies Nuget connection attempt failed "Unable to load the service index for source" Token based authentication in Web API without any user interface

Examples related to winforms

How to set combobox default value? Get the cell value of a GridView row Getting the first and last day of a month, using a given DateTime object Check if a record exists in the database Delete a row in DataGridView Control in VB.NET How to make picturebox transparent? Set default format of datetimepicker as dd-MM-yyyy Changing datagridview cell color based on condition C# Inserting Data from a form into an access Database How to use ConfigurationManager

Examples related to performance

Why is 2 * (i * i) faster than 2 * i * i in Java? What is the difference between spark.sql.shuffle.partitions and spark.default.parallelism? How to check if a key exists in Json Object and get its value Why does C++ code for testing the Collatz conjecture run faster than hand-written assembly? Most efficient way to map function over numpy array The most efficient way to remove first N elements in a list? Fastest way to get the first n elements of a List into an Array Why is "1000000000000000 in range(1000000000000001)" so fast in Python 3? pandas loc vs. iloc vs. at vs. iat? Android Recyclerview vs ListView with Viewholder

Examples related to logging

How to redirect docker container logs to a single file? Console logging for react? Hide strange unwanted Xcode logs Where are logs located? Retrieve last 100 lines logs Spring Boot - How to log all requests and responses with exceptions in single place? How do I get logs from all pods of a Kubernetes replication controller? Where is the Docker daemon log? How to log SQL statements in Spring Boot? How to do logging in React Native?