Use Log4Net in C# windows form Application

we are going to learn on how to use the Log4Net library for creating logs. Create a new windows form application in VS.

1. Install Log4Net library
2. Add to AssemblyInfo.cs 
3. Configure in App.config
4. Use in code 

Install Log4Net library
Then install the Log4Net library from the Nuget Package library.

•           log4net by The Apache software foundation 2.0.8 (i installed the latest).

Add to AssemblyInfo.cs 
After installing this package, open up AssemblyInfo.cs file under the Properties folder and add the log4net assembly information into it (under the other assembly information.).
   [assembly: log4net.Config.XmlConfigurator(Watch=true)] 


Configure in App.config

Now, open the App.config file and enter required details for LogNet to work.

<configSections>  
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=1b44e1d426115821" /> </configSections>  
<!-- Log4net Logging Setup -->  
<log4net>  
    <appender name="FileAppender" type="log4net.Appender.FileAppender,log4net">  
        <file value="D:\\POC\\MVPProject\\MVPProject\\Log\\mylogfile.txt" />  
        <!-- the location where the log file would be created -->  
        <appendToFile value="true" />  
        <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />  
        <layout type="log4net.Layout.PatternLayout">  
            <conversionPattern value="%date [%thread] %level %logger - %message%newline" /> </layout>  
        <filter type="log4net.Filter.LevelRangeFilter">  
            <levelMin value="INFO" />  
            <levelMax value="FATAL" /> </filter>  
    </appender>  
    <root>  
        <level value="DEBUG" />  
        <appender-ref ref="FileAppender" /> </root>  

</log4net>  

Use in code 
Use it in form like below,
public partial class Form1 : Form
    {
        public log4net.ILog log;


        public Form1()
        {
            log4net.Config.BasicConfigurator.Configure();
            log = log4net.LogManager.GetLogger(typeof(Program));
            InitializeComponent();

            log.Info("form constructor");
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            log.Info("form load");
        }

        private void button1_Click(object sender, EventArgs e)
        {
            log.Info("button click");
        }
    }

Ref : https://haacked.com/archive/2006/01/13/SettingUpLog4NetForMultiLayeredApplications.aspx/
https://www.c-sharpcorner.com/blogs/use-log4net-in-c-sharp-console-application

RollingFileAppender :

<log4net>

<root>

 <level value="DEBUG" />

 <appender-ref ref="LogFileAppender" />

</root>

<appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender" >

 <param name="File" value="C:\Try\logger\logger\bin\Debug\log.txt" />

 <param name="AppendToFile" value="true" />

 <rollingStyle value="Size" />

 <maxSizeRollBackups value="10" />

 <maximumFileSize value="10MB" />

 <staticLogFileName value="true" />

 <layout type="log4net.Layout.PatternLayout">

 <param name="ConversionPattern" value="%-5p%d{yyyy-MM-dd hh:mm:ss} – %m%n" />

 </layout>

</appender>

</log4net>