C#实现一个简单的日志类
上个月换工作，新项目又要重新搭建基础框架，把日志实现部分单独记录下来方便以后参考。
自定义日志类
代码大部分使用ChatGPT生成，人工进行了测试和优化，主要特点：
- 线程安全，日志异步写入文件不影响业务逻辑
- 支持过期文件自动清理，也可自定义清理逻辑
- 缓存队列有内存上限防呆，防止异常情况下内存爆满
- 提供默认的静态日志记录器，也支持自定义多个日志记录器
- 通过委托方法支持日志文件名、日志记录格式的自定义，更加自由
使用方法：
//正常写入日志
LogManager.Info("This is an info message: {0}", "TestInfo");
LogManager.Debug("This is a debug message: {0}", "TestDebug");
LogManager.Warn("This is an warning message: {0}", "TestInfo");
LogManager.Error("This is a error message: {0}", "TestDebug");
//自定义写入日志，一般情况下使用枚举定义日志记录器的名称
var logger = LogManager.GetLogger("测试日志");
logger.Info("This is an info message: {0}", "TestInfo");
logger.Debug("This is a debug message: {0}", "TestDebug");
logger.Warn("This is an warning message: {0}", "TestInfo");
logger.Error("This is a error message: {0}", "TestDebug");
// 在程序退出前关闭所有日志记录器，默认超时时间是3秒
LogManager.Close(5);
//调试时偶尔使用
if (LogManager.LastException != null)
{
Console.WriteLine("日志异常:" + LogManager.LastException);
}
配置方法(一般情况下使用默认配置即可)：
//自定义日志保存路径，默认保存到程序启动目录下的Log文件夹
LogManager.CustomLogPath = () => AppDomain.CurrentDomain.BaseDirectory + "\\CustomLogs";
//自定义日志文件名称，默认文件名为 DateTime.Now.ToString("yyyy-MM-dd") + ".log"
LogManager.CustomLogFileName = () => "MyLog_" + DateTime.Now.ToString("yyyyMMdd") + ".log";
//日志保存天数，默认30天
LogManager.SaveDays = 10;
//日志记录的格式，默认为 $"[{Time:yyyy-MM-dd HH:mm:ss ffff}] [{Level.ToString().ToUpper()}] [{ThreadId}] {Message}"
LogManager.LogFormatter = (item) =>
{
//可以在这里做日志等级筛选，如果返回string.Empty这该条日志不会记录到文件
return $"{item.Time:yyyy/MM/dd HH:mm:ss.fff} | {item.Level} | T{item.ThreadId:0000} | {item.Message}";
};
//日志回调，可用于界面实时显示日志或日志保存其它存储介质
LogManager.OnWriteLog = (item) => Console.WriteLine("An event was logged: " + item.ToString());
日志类完整代码：
using System;
using System.Collections.Concurrent;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
/// <summary>
/// 日志组件，内部维护了一个静态日志记录类
/// </summary>
public static class LogManager
{
/// <summary>
/// 日志等级
/// </summary>
public enum LogLevel
{ Debug, Info, Warn, Error, Fatal }
/// <summary>
/// 日志数据
/// </summary>
public class LogItem
{
public LogItem(LogLevel level, string message)
{
Level = level;
Message = message;
Time = DateTime.Now;
ThreadId = Thread.CurrentThread.ManagedThreadId;
}
public DateTime Time { get; private set; }
public LogLevel Level { get; private set; }
public int ThreadId { get; private set; }
public string Message { get; private set; }
public override string ToString()
{
return $"[{Time:yyyy-MM-dd HH:mm:ss ffff}] [{Level.ToString().ToUpper()}] [{ThreadId}] {Message}";
}
}
/// <summary>
/// 线程安全异步日志基础类，默认缓存10000条日志，超出时日志会阻塞
/// </summary>
public class Logger
{
/// <summary>
/// 日志文件存储路径的委托
/// </summary>
public Func<string> CustomLogPath { get; set; }
/// <summary>
/// 日志文件名的委托，文件扩展名必须是log，否则会影响日志文件的自动清理（可以自定义清理的方法）
/// </summary>
public Func<string> CustomLogFileName { get; set; }
/// <summary>
/// 日志文件保存时间
/// </summary>
public int SaveDays { get; set; } = 30;
/// <summary>
/// 日志格式化委托实例
/// </summary>
public Func<LogItem, string> LogFormatter { get; set; }
/// <summary>
/// 写日志事件
/// </summary>
public Action<LogItem> OnWriteLog { get; set; }
/// <summary>
/// 日志清理委托实例，传入日志保存时间
/// </summary>
public Action<int> LogCleanup { get; set; }
/// <summary>
/// 最后一次异常（仅调试时用，不用于正常业务流程）
/// </summary>
public Exception LastException { get; set; }
// 线程安全的日志队列
private BlockingCollection<string> logQueue = new BlockingCollection<string>(10000);
// 标识是否允许写入新日志
private bool allowNewLogs = true;
public Logger()
{
Task.Factory.StartNew(WriteToFile, TaskCreationOptions.LongRunning);
}
// 添加日志至队列方法
public void EnqueueLog(LogLevel level, string message)
{
if (!allowNewLogs) return;
LogItem item = new LogItem(level, message);
string logMessage;
if (LogFormatter != null)
{
logMessage = LogFormatter(item);
}
else
{
logMessage = item.ToString();
}
if (!string.IsNullOrWhiteSpace(logMessage))
{
logQueue.Add(logMessage);
}
OnWriteLog?.Invoke(item);
}
// 循环写入写日志到文件
private void WriteToFile()
{
string logPath = CustomLogPath?.Invoke() ?? AppDomain.CurrentDomain.BaseDirectory + "\\Log";
DirectoryInfo logDir = Directory.CreateDirectory(logPath);
while (true)
{
try
{
if (!allowNewLogs && logQueue.Count == 0) break;
string logMessage;
if (logQueue.TryTake(out logMessage, TimeSpan.FromSeconds(1)))
{
string fileName = CustomLogFileName?.Invoke() ?? DateTime.Now.ToString("yyyy-MM-dd") + ".log";
if (!File.Exists(fileName))
{
// 清理旧日志
if (LogCleanup != null)
{
LogCleanup(SaveDays);
}
else
{
CleanUpOldLogs(logDir, SaveDays);
}
}
File.AppendAllText(Path.Combine(logPath, fileName), logMessage + Environment.NewLine);
}
}
catch (Exception ex)
{
LastException = ex;
Console.WriteLine("Logger Exception - WriteToFile : " + ex.Message);
}
}
}
/// <summary>
/// 关闭日志器方法，指定超时时间（秒）
/// </summary>
/// <param name="waitTimeInSeconds">等待时间</param>
public void Close(int waitTimeInSeconds = 3)
{
allowNewLogs = false;
CancellationTokenSource cts = new CancellationTokenSource(TimeSpan.FromSeconds(waitTimeInSeconds));
try
{
CancellationToken token = cts.Token;
// 标识队列已完成添加
logQueue.CompleteAdding();
while (!token.IsCancellationRequested)
{
if (logQueue.Count == 0) break; // 提前退出
// 短暂休眠以降低 CPU 占用
Task.Delay(100, token).Wait();
}
}
catch (OperationCanceledException)
{
// 等待时间到，退出方法，不传播异常
}
catch (Exception ex)
{
Console.WriteLine("An unexpected exception occurred in the Close method: " + ex.Message);
}
}
/// <summary>
/// 默认的清理过期日志的方法
/// </summary>
/// <param name="logDir"></param>
/// <param name="saveDays"></param>
public static void CleanUpOldLogs(DirectoryInfo logDir, int saveDays)
{
FileInfo[] logFiles = logDir.GetFiles("*.log");
foreach (FileInfo file in logFiles)
{
if (DateTime.Now - file.CreationTime >= TimeSpan.FromDays(saveDays))
{
file.Delete();
}
}
}
/// <summary>
/// 记录Info等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public void Info(string message, params object[] args)
{
EnqueueLog(LogLevel.Info, string.Format(message, args));
}
/// <summary>
/// 记录Debug等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public void Debug(string message, params object[] args)
{
EnqueueLog(LogLevel.Debug, string.Format(message, args));
}
/// <summary>
/// 记录Warning等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public void Warn(string message, params object[] args)
{
EnqueueLog(LogLevel.Warn, string.Format(message, args));
}
/// <summary>
/// 记录Error等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public void Error(string message, params object[] args)
{
EnqueueLog(LogLevel.Error, string.Format(message, args));
}
/// <summary>
/// 记录Fatal等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public void Fatal(string message, params object[] args)
{
EnqueueLog(LogLevel.Fatal, string.Format(message, args));
}
}
private static Logger logger = new Logger();
private static ConcurrentDictionary<string, Logger> logDic = new ConcurrentDictionary<string, Logger>();
/// <summary>
/// 获取自定义的日志记录类
/// </summary>
/// <param name="name"></param>
/// <returns></returns>
public static Logger GetLogger(string name)
{
return logDic.GetOrAdd(name, key =>
{
var log = new Logger();
log.CustomLogPath = () => AppDomain.CurrentDomain.BaseDirectory + "\\Log\\" + key;
return log;
});
}
/// <summary>
/// 日志文件存储路径的委托
/// </summary>
public static Func<string> CustomLogPath
{
get => logger.CustomLogPath;
set => logger.CustomLogPath = value;
}
/// <summary>
/// 日志文件名的委托，文件扩展名必须是log，否则会影响日志文件的自动清理（可以自定义清理的方法）
/// </summary>
public static Func<string> CustomLogFileName
{
get => logger.CustomLogFileName;
set => logger.CustomLogFileName = value;
}
/// <summary>
/// 日志文件保存时间
/// </summary>
public static int SaveDays
{
get => logger.SaveDays;
set => logger.SaveDays = value;
}
/// <summary>
/// 日志格式化委托实例
/// </summary>
public static Func<LogItem, string> LogFormatter
{
get => logger.LogFormatter;
set => logger.LogFormatter = value;
}
/// <summary>
/// 写日志事件
/// </summary>
public static Action<LogItem> OnWriteLog
{
get => logger.OnWriteLog;
set => logger.OnWriteLog = value;
}
/// <summary>
/// 日志清理委托实例，传入日志保存时间
/// </summary>
public static Action<int> LogCleanup
{
get => logger.LogCleanup;
set => logger.LogCleanup = value;
}
/// <summary>
/// 最后一次异常（仅调试时用，不用于正常业务流程）
/// </summary>
public static Exception LastException
{
get => logger.LastException;
set => logger.LastException = value;
}
/// <summary>
/// 关闭所有日志记录器，指定超时时间（秒），日志记录器较多时可能耗时较久
/// </summary>
/// <param name="waitTimeInSeconds">等待时间</param>
public static void Close(int waitTimeInSeconds = 3)
{
logger.Close(waitTimeInSeconds);
foreach (var item in logDic.Values)
{
item.Close(waitTimeInSeconds);
}
}
/// <summary>
/// 记录Info等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Info(string message, params object[] args)
{
logger.EnqueueLog(LogLevel.Info, string.Format(message, args));
}
/// <summary>
/// 记录Debug等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Debug(string message, params object[] args)
{
logger.EnqueueLog(LogLevel.Debug, string.Format(message, args));
}
/// <summary>
/// 记录Warning等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Warn(string message, params object[] args)
{
logger.EnqueueLog(LogLevel.Warn, string.Format(message, args));
}
/// <summary>
/// 记录Error等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Error(string message, params object[] args)
{
logger.EnqueueLog(LogLevel.Error, string.Format(message, args));
}
/// <summary>
/// 记录Fatal等级日志
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Fatal(string message, params object[] args)
{
logger.EnqueueLog(LogLevel.Fatal, string.Format(message, args));
}
}
NLog版本的日志类
有时候因为公司或团队原因必须使用NLog日志库，这里提供一个简单的NLog版本的日志类，日志规则基本和上面的自定义类一致。
使用方法如下：
//可以指定日志保存天数，默认30天
Logger.Init();
//订阅写日志事件
Logger.GetLogEventTarget().LogReceived += Logger_LogWrite;
//记录日志
Logger.Info("软件启动");
NLog版本的日志类只是对NLog的常用配置做一个封装，如果需要自定义日志格式或存储位置需要自己改封装部分的代码。
完整代码：
using NLog;
using NLog.Config;
using NLog.Layouts;
using NLog.Targets;
using NLog.Targets.Wrappers;
using System;
/// <summary>
/// 全局日志类
/// </summary>
public static class Logger
{
#region 私有字段方法
private static ILogger logger;
private static void ConfigureNLog(int saveDays = 30)
{
var config = new LoggingConfiguration();
// 创建目标（这里是 FileTarget 用于写入文件）
var fileTarget = new FileTarget("logfile")
{
FileName = "${basedir}/Log/${date:format=yyyy-MM-dd}.log",
Layout = "${longdate} ${uppercase:${level}} ${message} ${exception:format=tostring}",
ArchiveOldFileOnStartup = true,
ArchiveEvery = FileArchivePeriod.Day,
MaxArchiveFiles = saveDays,
};
// 使用 AsyncTargetWrapper 实现异步写日志
var asyncFileTarget = new AsyncTargetWrapper(fileTarget, 1000, AsyncTargetWrapperOverflowAction.Discard);
// 设置规则
var rule = new LoggingRule("*", LogLevel.Debug, asyncFileTarget);
config.LoggingRules.Add(rule);
// 创建自定义Target
var logEventTarget = new LogEventTarget
{
Name = "logEvent",
MessageLayout = "${longdate} ${uppercase:${level}} ${message} ${exception:format=tostring}"
};
config.AddTarget(logEventTarget);
// 添加规则
var eventRule = new LoggingRule("*", LogLevel.Debug, logEventTarget);
config.LoggingRules.Add(eventRule);
// 应用配置
LogManager.Configuration = config;
}
#endregion 私有字段方法
#region 公共字段方法
/// <summary>
/// 初始化日志，程序初始化时启动
/// </summary>
/// <param name="saveDays"></param>
public static void Init(int saveDays = 30)
{
ConfigureNLog(saveDays);
logger = LogManager.GetCurrentClassLogger();
}
/// <summary>
/// 获取日志回调Target
/// </summary>
/// <returns></returns>
public static LogEventTarget GetLogEventTarget()
{
return (LogEventTarget)LogManager.Configuration.FindTargetByName("logEvent");
}
/// <summary>
/// 关闭日志，程序退出时调用
/// </summary>
public static void Close()
{
LogManager.Flush();
LogManager.Shutdown();
}
#endregion 公共字段方法
#region 日志接口
/// <summary>
/// 跟踪日志级别：最详细的级别，用于开发，很少用于生产。
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Trace(string message, params object[] args)
{
logger.Trace(message, args);
}
/// <summary>
/// 调试日志级别：根据感兴趣的内部事件调试应用程序行为。
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Debug(string message, params object[] args)
{
logger.Debug(message, args);
}
/// <summary>
/// 信息日志级别：突出显示进度或应用程序生存期事件的信息。
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Info(string message, params object[] args)
{
logger.Info(message, args);
}
/// <summary>
/// 警告日志级别：关于可以恢复的验证问题或临时故障的警告。
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Warn(string message, params object[] args)
{
logger.Warn(message, args);
}
/// <summary>
/// 错误日志级别：功能失败或捕捉到System.Exception的错误。
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Error(string message, params object?[] args)
{
logger.Error(message, args);
}
/// <summary>
/// 致命日志级别：最关键级别，应用程序即将中止。
/// </summary>
/// <param name="message"></param>
/// <param name="args"></param>
public static void Fatal(string message, params object[] args)
{
logger.Fatal(message, args);
}
#endregion 日志接口
}
/// <summary>
/// 日志事件目标
/// </summary>
public class LogEventTarget : Target
{
/// <summary>
/// 日志事件
/// </summary>
public event EventHandler<string> LogReceived;
/// <summary>
/// 日志布局
/// </summary>
[RequiredParameter]
public Layout MessageLayout { get; set; }
protected override void Write(LogEventInfo logEvent)
{
string logMessage = MessageLayout.Render(logEvent);
OnLogReceived(logMessage);
}
private void OnLogReceived(string message)
{
LogReceived?.Invoke(this, message);
}
}
Serilog版本的日志类
Serilog 是用于 .NET 应用程序的诊断日志记录库。它易于设置，具有干净的 API，并且可以在所有最新的 .NET 平台上运行。
github链接:Serilog
安装以下NuGet包：
使用方法如下：
Log.Logger = new LoggerConfiguration()
.MinimumLevel.Debug()
.WriteTo.Console()
//异步写入，滚动间隔：天，默认情况下只保留最近的 31 个文件
.WriteTo.Async(a => a.File("logs/log-.txt", rollingInterval: RollingInterval.Day, retainedFileCountLimit: 60))
.WriteTo.MySink()
.CreateLogger();
Log.Information("Hello, world!");
// 最后，在应用程序退出之前。。。
Log.CloseAndFlush();
自定义日志计算器如下：
public class MySink : ILogEventSink
{
private readonly IFormatProvider _formatProvider;
public MySink(IFormatProvider formatProvider)
{
_formatProvider = formatProvider;
}
public void Emit(LogEvent logEvent)
{
var message = logEvent.RenderMessage(_formatProvider);
//自己实现写入到界面控件或其它日志中心
Console.WriteLine(DateTimeOffset.Now.ToString() + " " + message);
}
}
public static class MySinkExtensions
{
public static LoggerConfiguration MySink(
this LoggerSinkConfiguration loggerConfiguration,
IFormatProvider formatProvider = null)
{
return loggerConfiguration.Sink(new MySink(formatProvider));
}
}
