如何使用 ConsoleLoggerProvider 创建 LoggerFactory？

Question

ConsoleLoggerProvider(IConsoleLoggerSettings)
ConsoleLoggerProvider(IOptionsMonitor<ConsoleLoggerOptions>)
ConsoleLoggerProvider(Func<String,LogLevel,Boolean>, Boolean)
ConsoleLoggerProvider(Func<String,LogLevel,Boolean>, Boolean, Boolean)

其中三个被宣布为已过时的消息：

This method is obsolete and will be removed in a future version. The recommended alternative is using LoggerFactory to configure filtering and ConsoleLoggerOptions to configure logging options.

使用构造函数 #3，创建带有 ConsoleLoggerProvider 的 LoggerFactory 非常简单（如 Entity Framework Core - Logging 中所述）：

var loggerFactory = new LoggerFactory(new[] { new ConsoleLoggerProvider((category, level) => level >= LogLevel.Information, true) });

但由于它已被弃用，我们只剩下构造函数 #2。这是我发现的等效内容：

var configureNamedOptions = new ConfigureNamedOptions<ConsoleLoggerOptions>("", null);
var optionsFactory = new OptionsFactory<ConsoleLoggerOptions>(new []{ configureNamedOptions }, Enumerable.Empty<IPostConfigureOptions<ConsoleLoggerOptions>>());
var optionsMonitor = new OptionsMonitor<ConsoleLoggerOptions>(optionsFactory, Enumerable.Empty<IOptionsChangeTokenSource<ConsoleLoggerOptions>>(), new OptionsCache<ConsoleLoggerOptions>());
var loggerFactory = new LoggerFactory(new[] { new ConsoleLoggerProvider(optionsMonitor) }, new LoggerFilterOptions { MinLevel = LogLevel.Information });

这看起来太复杂了，我是不是漏掉了一些更简单的东西？

Answer 1

在 .NET Core 2.2 中，您可以通过 Microsoft 的依赖注入框架构建一个 ILoggerFactory 而无需使用过时的方法。它比所有内容都是手动构建的版本更简洁。方法如下：

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

IServiceCollection serviceCollection = new ServiceCollection();
serviceCollection.AddLogging(builder => builder
    .AddConsole()
    .AddFilter(level => level >= LogLevel.Information)
);
var loggerFactory = serviceCollection.BuildServiceProvider().GetService<ILoggerFactory>();

而在 .NET Core 3.0 中，您可以使用 LoggerFactory.Create:

var loggerFactory = LoggerFactory.Create(builder => {
        builder.AddFilter("Microsoft", LogLevel.Warning)
               .AddFilter("System", LogLevel.Warning)
               .AddFilter("SampleApp.Program", LogLevel.Debug)
               .AddConsole();
    }
);

另请参阅：

Migrate from Microsoft.Extensions.Logging 2.1 to 2.2 or 3.0

Answer 2

@0xced 感谢您解构的示例，因为委托在 Powershell 中不起作用，这帮助我在 Powershell 中做同样的事情：

$optionsFactory = [OptionsFactory[ConsoleLoggerOptions]]::new(
    [List[ConfigureNamedOptions[ConsoleLoggerOptions]]]@(
        [ConfigureNamedOptions[ConsoleLoggerOptions]]::new('',$null)
    ),
    [List[IPostConfigureOptions[ConsoleLoggerOptions]]]::new()
)

$optionsMonitor = [OptionsMonitor[ConsoleLoggerOptions]]::new(
    $optionsFactory,
    [List[IOptionsChangeTokenSource[ConsoleLoggerOptions]]]::new(),
    [OptionsCache[ConsoleLoggerOptions]]::new()
)

$consoleLoggerProvider = [ConsoleLoggerProvider]$OptionsMonitor
$consoleLoggerProviderList = [List[ILoggerProvider]]::new()
$consoleLoggerProviderList.add($consoleLoggerProvider)

$loggerFactory = [LoggerFactory]::new(
    $consoleLoggerProviderList,
    [LoggerFilterOptions]@{
        MinLevel = [LogLevel]::Information
    }
)

Answer 3

以防万一，如果有人想在 ASP.NET efcore 的核心组合根中进行：

services.AddDbContext<DbContext>(opt => {
    opt.AddSqlServer(Configuration.GetConnectionString("DefaultConnection"));
    opt.UseLoggerFactory(LoggerFactory.Create(builder => { builder.AddConsole(); }));
});

如何使用 ConsoleLoggerProvider 创建 LoggerFactory？

How to create a LoggerFactory with a ConsoleLoggerProvider?

.net-core

asp.net-core-2.2