首先引用NLog的dll文件

using System.IO;

using NLog;

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基础日志类

/// <summary>
/// 写日志
/// </summary>
public class WriteLog
{
private static Logger logger = LogManager.GetCurrentClassLogger();
private static string filebasepath = AppDomain.CurrentDomain.BaseDirectory + "Logs\\";

/// <summary>
/// 写日志
/// </summary>
/// <param name="log">日志内容</param>
public void WriteComLog(string log)
{
//记录警告信息
logger.Warn(log);
}

/// <summary>
/// 根据名称分类写日志
/// </summary>
/// <param name="log">日志内容</param>
/// <param name="logname">日志类别名称</param>
public void WriteComLog(string log, string logname)
{
Logger loggerByName = LogManager.GetLogger(logname);
//记录一般信息
loggerByName.Info(log);
}

/// <summary>
/// 将信息写入文件
/// </summary>
/// <param name="info">信息</param>
/// <param name="filename">文件名</param>
/// <param name="filefix">文件后缀名</param>
public void WriteFile(string info, string filename, string filefix)
{
try
{
//文件夹路径
string _filebasepath = GetTodyRecordPath();
string filePath = string.Empty;

if (string.IsNullOrEmpty(filefix))
{
//日志文件路径
filePath = _filebasepath + "\\" + filename + ".log";
}
else
{
filePath = _filebasepath + "\\" + filename + filefix;
}
//如果file文件夹不存在创建file文件夹
if (!System.IO.Directory.Exists(_filebasepath))
{
Directory.CreateDirectory(_filebasepath);
}
//如果文件不存在创建该文件
if (!File.Exists(filePath))
{
File.Create(filePath).Close();
}
StreamWriter sw = File.AppendText(filePath);
sw.Write(info);
sw.Close();
}
catch
{

}
}

/// <summary>
/// 将信息写入文件
/// </summary>
/// <param name="info">信息</param>
/// <param name="filename">文件名</param>
/// <param name="filefix">文件后缀名</param>
/// <param name="childpath"></param>
public void WriteFile(string info, string filename, string filefix,string childpath)
{
try
{
string _filebasepath = GetTodyRecordPath()+childpath;
string filePath = string.Empty;

if (string.IsNullOrEmpty(filefix))
{
filePath = _filebasepath + "\\" + filename + ".log";
}
else
{
filePath = _filebasepath + "\\" + filename + filefix;
}

if (!System.IO.Directory.Exists(_filebasepath))
{
Directory.CreateDirectory(_filebasepath);
}
//如果文件不存在创建该文件
if (!File.Exists(filePath))
{
File.Create(filePath).Close();
}
//将日志文件追加到日志文件夹下
StreamWriter sw = File.AppendText(filePath);
//将日志的内容写入日志文件中
sw.Write(info);
sw.Close();
}
catch
{

}
}

/// <summary>
/// 获取当前日期文件夹
/// </summary>
/// <returns>createPath文件夹路径</returns>
private string GetTodyRecordPath()
{
string createPath = string.Empty;
//如果不存在就创建file文件夹
if (Directory.Exists(filebasepath + DateTime.Now.Year.ToString()) == false)
{
//创建文件夹
Directory.CreateDirectory(filebasepath + DateTime.Now.Year.ToString());
//获取文件夹路径
createPath = DateTime.Now.Year.ToString() + @"\";
}

if (Directory.Exists(filebasepath + DateTime.Now.Year.ToString()+"/"+DateTime.Now.Month.ToString()) == false)
{
Directory.CreateDirectory(filebasepath + DateTime.Now.Year.ToString() + "/" + DateTime.Now.Month.ToString());
createPath = DateTime.Now.Year.ToString() + @"\"+DateTime.Now.Month.ToString()+@"\";
}

if (Directory.Exists(filebasepath + DateTime.Now.Year.ToString() + "/" + DateTime.Now.Month.ToString()+"/"+DateTime.Now.ToString("yyyyMMdd")) == false)
{
Directory.CreateDirectory(filebasepath + DateTime.Now.Year.ToString() + "/" + DateTime.Now.Month.ToString() + "/" +DateTime.Now.ToString("dd"));
createPath = DateTime.Now.Year.ToString() + @"\"+DateTime.Now.Month.ToString()+@"\"+DateTime.Now.ToString("dd")+"/";
}
createPath = filebasepath + DateTime.Now.Year.ToString() + @"\" + DateTime.Now.Month.ToString() + @"\" + DateTime.Now.ToString("dd") + @"\";
return createPath;
}

}

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C#操作日志