asp.net core3.1 使用log4日志

1.NuGet包：

　　log4net.AspNetCore

　　Microsoft.Extensions.Logging.Log4Net.AspNetCore

 

添加配置文件 log4net.config

　　

<?xml version="1.0" encoding="utf-8"?>
<log4net>
    <!-- Define some output appenders -->
    <appender name="rollingAppender" type="log4net.Appender.RollingFileAppender">
        <file value="log\log.txt" />

        <!--追加日志內容-->
        <appendToFile value="true" />

        <!--防止多線程時不能寫Log,官方說線程非安全-->
        <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />

        <!--可以為:Once|Size|Date|Composite-->
        <!--Composite為Size和Date的組合-->
        <rollingStyle value="Composite" />

        <!--當備份文件時,為文件名加的后綴-->
        <datePattern value="yyyyMMdd.TXT" />

        <!--日志最大個數,都是最新的-->
        <!--rollingStyle節點為Size時,只能有value個日志-->
        <!--rollingStyle節點為Composite時,每天有value個日志-->
        <maxSizeRollBackups value="20" />

        <!--可用的單位:KB|MB|GB-->
        <maximumFileSize value="3MB" />

        <!--置為true,當前最新日志文件名永遠為file節中的名字-->
        <staticLogFileName value="true" />

        <!--輸出級別在INFO和ERROR之間的日志-->
        <filter type="log4net.Filter.LevelRangeFilter">
            <param name="LevelMin" value="INFO" />
            <param name="LevelMax" value="FATAL" />
        </filter>

        <layout type="log4net.Layout.PatternLayout">
            <conversionPattern value="%date [%thread] %-5level %logger - %message%newline"/>
        </layout>
    </appender>

    <!-- levels: OFF > FATAL > ERROR > WARN > INFO > DEBUG  > ALL -->
    <root>
        <priority value="ALL"/>
        <level value="ALL"/>
        <appender-ref ref="rollingAppender" />
    </root>
</log4net>

2.配置 CreateHostBuilder

public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args).
                ConfigureLogging(loggingBuilder =>
                {
                    //loggingBuilder.AddFilter("System", LogLevel.Warning);   //過濾系統日志
                    //loggingBuilder.AddFilter("Microsoft", LogLevel.Warning);
                    loggingBuilder.AddLog4Net();//需要配置文件
                })
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                });

3.使用

public class FirstController : Controller
    {
        private readonly ILogger<FirstController> _logger;

        public FirstController(ILogger<FirstController> logger)
        {
            _logger = logger;
        }
        public IActionResult Index()
        {
            Console.WriteLine("測試日志");
            _logger.LogWarning("測試日志");
            return View();
        }
    }