• Log4Net for Logging in Windows Form Desktop Application | TheCodeBuzz
• dependency injection in Windows forms and EF core – Microsoft Q&A

สร้างโปรเจ็กส์แบบ Windows Forms App (winforms) ชื่อ WinFormsApp1

ดูไฟล์ Program.cs

namespace WinFormsApp1
{
    internal static class Program
    {
        /// <summary>
        ///  The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            // To customize application configuration such as set high DPI settings or default font,
            // see https://aka.ms/applicationconfiguration.
            ApplicationConfiguration.Initialize();
            Application.Run(new Form1());
        }
    }
}

ดูไฟล์ Form1.cs

namespace WinFormsApp1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
    }
}

ติดตั้ง Package log4net , Microsoft.Extensions.Hosting และ Microsoft.Extensions.Logging.Log4Net.AspNetCore

ดูไฟล์ WinFormsApp1.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net6.0-windows</TargetFramework>
    <Nullable>enable</Nullable>
    <UseWindowsForms>true</UseWindowsForms>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="log4net" Version="2.0.15" />
    <PackageReference Include="Microsoft.Extensions.Hosting" Version="6.0.1" />
    <PackageReference Include="Microsoft.Extensions.Logging.Log4Net.AspNetCore" Version="6.1.0" />
  </ItemGroup>

</Project>

สร้างไฟล์ log4net.config และ ตั้งค่า Copy to Output Directory เป็น Copy always

<?xml version="1.0" encoding="utf-8" ?>
<log4net>
  <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
    <lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
    <file value="log/" />
    <datePattern value="yyMMdd'Jack.log'" />
    <staticLogFileName value="false"/>
    <appendToFile value="true"/>
    <rollingStyle value="Date"/>
    <maxSizeRollBackups value="100"/>
    <maximumFileSize value="15MB"/>
    <encoding value="UTF-8"/>
    <layout type="log4net.Layout.PatternLayout">
      <param name="ConversionPattern" value="%-5p%d{ HH:mm:ss} li:%line - [%method] %m  %n" />
    </layout>
  </appender>
  <root>
    <level value="ALL"/>
    <appender-ref ref="RollingLogFileAppender"/>
  </root>
</log4net>

แก้ไขไฟล์ Program.cs

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace WinFormsApp1
{
    internal static class Program
    {
        /// <summary>
        ///  The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            // To customize application configuration such as set high DPI settings or default font,
            // see https://aka.ms/applicationconfiguration.
            ApplicationConfiguration.Initialize();

            ///Generate Host Builder and Register the Services for DI
            var builder = new HostBuilder()
               .ConfigureServices((hostContext, services) =>
               {
                   //Register all your services here
                   services.AddLogging(configure => configure.AddConsole())
                           .AddScoped<Form1>();
               }).ConfigureLogging(logBuilder =>
               {
                   logBuilder.SetMinimumLevel(LogLevel.Trace);
                   logBuilder.AddLog4Net("log4net.config");
               });

            var host = builder.Build();

            using (var serviceScope = host.Services.CreateScope())
            {
                var services = serviceScope.ServiceProvider;
                try
                {
                    var form1 = services.GetRequiredService<Form1>();
                    Application.Run(form1);

                    Console.WriteLine("Success");
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Error");
                    Console.WriteLine(ex.ToString());
                }
            }
        }
    }
}

แก้ไขไฟล์ Form1.cs

using Microsoft.Extensions.Logging;

namespace WinFormsApp1
{
    public partial class Form1 : Form
    {
        private readonly ILogger _logger;
        public Form1(ILogger<Form1> logger)
        {
            InitializeComponent();
            _logger = logger;

            try
            {
                _logger.LogInformation("Form1 Started");
                MessageBox.Show("Hello World!");
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.Message);
            }
        }
    }
}