步骤还是比较简单的：

1、引用 Microsoft.Extensions.Logging 包

2、创建EFLogger.cs文件，内容如下

    public class EFLogger: ILogger
    {
        private readonly string categoryName;

        public EFLogger(string categoryName) => this.categoryName = categoryName;

        public bool IsEnabled(LogLevel logLevel) => true;

        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
        {
            //ef core执行数据库查询时的categoryName为Microsoft.EntityFrameworkCore.Database.Command,日志级别为Information
            if (categoryName == "Microsoft.EntityFrameworkCore.Database.Command"
                    && logLevel == LogLevel.Information)
            {
                var logContent = formatter(state, exception);
                //TODO: 拿到日志内容想怎么玩就怎么玩吧
                Console.WriteLine();
                Console.ForegroundColor = ConsoleColor.Green;
                Console.WriteLine(logContent);
                Console.ResetColor();
            }
        }


        public IDisposable BeginScope<TState>(TState state) => null;
    }

3、创建 EFLoggerProvider.cs文件，内容如下

    public class EFLoggerProvider: ILoggerProvider
    {
        public ILogger CreateLogger(string categoryName) => new EFLogger(categoryName);
        public void Dispose() { }
    }

5、在efcore的配置方法Configure中添加如下代码

            dbContextOptions.UseLazyLoadingProxies().ConfigureWarnings(warnnings => warnnings.Log(CoreEventId.LazyLoadOnDisposedContextWarning));
            var loggerFactory = new LoggerFactory();
            loggerFactory.AddProvider(new EFLoggerProvider());
            dbContextOptions.UseLoggerFactory(loggerFactory);

这样，就可以在自启动的时候输出efcore生成的sql，从而进行拦截并且优化

ps：发布的时候需要禁用第五步的代码，否则会严重影响性能