使用 DI 并使用 appsettings.json 将 Nlog 日志记录到数据库 .NET 5.0

Question

我一直在尝试让 Nlog 将日志记录发送到数据库，但我发现的示例都返回了内部 nlog 错误。我在带有 .NET 5.0 的控制台应用程序中使用依赖注入...：

Info Adding target ConsoleTarget(Name=console)
Warn Error has been raised. Exception: NLog.NLogConfigurationException: Failed to create Target of type: Database
 ---> System.ArgumentException: Target cannot be found: 'Database'. Extension NLog.Database not included?
   at NLog.Config.Factory`2.CreateInstance(String itemName)
   at NLog.Config.LoggingConfigurationParser.FactoryCreateInstance[T](String classType, INamedItemFactory`2 factory)
   --- End of inner exception stack trace ---
Warn Error has been raised. Exception: NLog.NLogConfigurationException: Target 'dbTarget' not found for logging rule: *.

在我的 json 中，我有以下内容：

  "NLog": {
    "internalLogLevel": "info",
    "internalLogFile": "${basedir}/logs/internal-nlog.txt",
    "extensions": {
      "NLog.Extensions.Logging": {
        "assembly": "NLog.Web.AspNetCore"
      }
    },
    "targets": {
      "database": {
        "type": "Database",
        "name": "dbTarget",
        "dbProvider": "Microsoft.Data.SqlClient.SqlConnection,Microsoft.Data.SqlClient",
        "connectionString": "myconnectionstring",
        "commandText": "INSERT INTO dbo.Logs (Level,CallSite,Type,Message,StackTrace,InnerException,AdditionalInfo) values (@level, @callSite, @type, @message, @stackTrace, @innerException, @additionalInfo)",
        "parameters": [
          {
            "lots of parameters follow"
          }
        ]

      }
    },
    "rules": [
      {
        "logger": "*",
        "minLevel": "Debug",
        "writeTo": "dbTarget"
      }
    ]

这是在我的 Main() 中：

        static void Main(string[] args)
        {
            ApplicationSettings applicationSettings = new ApplicationSettings();

            var settings = applicationSettings.GetConfiguration();

            var host = Host.CreateDefaultBuilder()
            .ConfigureServices((context, services) =>
            {
                services.AddSingleton<IApplicationSettings, ApplicationSettings>();
                services.AddSingleton<IApplication, Application>();
                services.AddSingleton<ITeamMemberProcessor, TeamMemberProcessor>();
                services.AddLogging(loggingBuilder =>
                {
                    loggingBuilder.ClearProviders();
                    loggingBuilder.AddNLog();
                });
            })
            .Build();
            

            var svc = ActivatorUtilities.CreateInstance<Application>(host.Services);
            svc.Run();
        }

我错过了什么吗？写入文件和写入控制台工作正常。另外，据我了解，不应再使用 nlog.config 了。我们应该使用 appsettings.json 吗？

谢谢！

戴夫

Answer 1

我猜你正在使用 NLog 5.0，其中 NLog DatabaseTarget 一直是 extracted into a seperate nuget-package。

猜猜错误信息想说什么：

Exception: NLog.NLogConfigurationException: Failed to create Target of type: Database
 ---> System.ArgumentException: Target cannot be found: 'Database'. Extension NLog.Database not included?

它希望您从 nuget 安装扩展程序 NLog.Database，并将其添加到 NLog 配置中。像这样的：

"NLog": {
    "internalLogLevel": "info",
    "internalLogFile": "${basedir}/logs/internal-nlog.txt",
    "extensions": [
      { "assembly": "NLog.Database" },
      { "assembly": "NLog.Web.AspNetCore" }
    ],
    "targets": {
        "database": {
        "type": "Database",
        "name": "dbTarget",
        "dbProvider": "Microsoft.Data.SqlClient.SqlConnection,Microsoft.Data.SqlClient",
        "connectionString": "myconnectionstring",
        "commandText": "INSERT INTO dbo.Logs (Level,CallSite,Type,Message,StackTrace,InnerException,AdditionalInfo) values (@level, @callSite, @type, @message, @stackTrace, @innerException, @additionalInfo)",
        "parameters": [
            {
            "lots of parameters follow"
            }
        ]

        }
    },
    "rules": [
        {
        "logger": "*",
        "minLevel": "Debug",
        "writeTo": "dbTarget"
        }
    ]
}

Answer 2

所以，我能够让它“工作”，尽管没有 DI.. 我仍然想弄清楚。看起来好像我的 ApplicationSettings 中缺少两行：

            LogManager.Configuration = new NLogLoggingConfiguration(_configuration.GetSection("NLog"));
            var logger = NLogBuilder.ConfigureNLog(LogManager.Configuration).GetCurrentClassLogger();

然后在我的“应用程序”类中，我删除了 Logging 注入，并将其添加到我的“运行”方法的顶部：

var _logger = LogManager.Setup().LoadConfigurationFromSection(_configuration).GetCurrentClassLogger();

然后它工作了.. 再次，我猜我错过了一些东西，所以我可以使用依赖注入？但我不确定是什么..

感谢您的回复，感谢您抽出宝贵时间！

戴夫