手动实现文件日志记录器（.NET 示例代码）

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	// 在原生的 Microsoft.Extensions.Logging 中没有内置的文件日志提供程序，但可以自定义实现：

	// Soccer.Infrastructure/Logging/FileLoggerProvider.cs

	public sealed class FileLoggerProvider : ILoggerProvider
	{
	private readonly StreamWriter _writer;
	private readonly object _lock = new();

	public FileLoggerProvider(string path)
	{
	Directory.CreateDirectory(Path.GetDirectoryName(path)!);
	_writer = new StreamWriter(path, append: true) { AutoFlush = true };
	}

	public ILogger CreateLogger(string categoryName) =>
	new FileLogger(categoryName, _writer, _lock);

	public void Dispose() => _writer.Dispose();
	}

	public sealed class FileLogger : ILogger
	{
	private readonly string _category;
	private readonly StreamWriter _writer;
	private readonly object _lock;

	public FileLogger(string category, StreamWriter writer, object @lock)
	{
	_category = category;
	_writer = writer;
	_lock = @lock;
	}

	public IDisposable? BeginScope(TState state) where TState : notnull => null;
	public bool IsEnabled(LogLevel logLevel) => logLevel >= LogLevel.Information;

	public void Log(
	LogLevel logLevel, EventId eventId, TState state,
	Exception? exception, Func formatter)
	{
	if (!IsEnabled(logLevel)) return;

	var line = $"{DateTime.UtcNow:O} [{logLevel}] {_category}: {formatter(state, exception)}";
	if (exception != null) line += Environment.NewLine + exception;

	lock (_lock) _writer.WriteLine(line);
	}
	}

	// 然后在 Program.cs 中进行注册：
	// builder.Logging.AddProvider(new FileLoggerProvider("logs/app.log"));

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