如何在.NET 6中获取ILoggerFactory

In .Net5 ILoggerFactory用作配置功能Startup.cs如下 ：

public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory)
{
    //here we used loggerFactory
    loggerFactory.AddProvider(loggerprovider);
}

In .Net6如何通过应用程序或构建器获取它

var app = builder.Build();

OR

var builder = WebApplication.CreateBuilder(args);

要获取实际的记录器工厂实例：

var app = builder.Build();
var lf = app.Services.GetRequiredService<ILoggerFactory>();

还可以使用 GetService 而不是 GetRequiredService。当服务不存在时，GetService 返回 null，并且 GetRequiredService 抛出异常。这里讨论的优点和缺点：

https://andrewlock.net/the-difference- Between-getservice-and-getrquiredservice-in-asp-net-core/ https://andrewlock.net/the-difference-between-getservice-and-getrquiredservice-in-asp-net-core/