简单的日志文件操作类 （C#）

类名称： log；

类方法（公有）：

1)  log (String)    构造函数，传入完整文件名。

2）bool writeln_log (String)   写入一行日志字符串。

3） static void del_log_file (String)   删除指定文件。

4） bool close_file ()   关闭文件

5)   (属性)  String filepath (读写)     获取或设置文件流打开的完整文件名，若设置则动态改变文件流，使之导向到新的文件。

使用方法：

using lib_ez;

log _log = new log (@"C:\testfile.dat");
_log.writeln_log ("add the first log string...");
_log.writeln_log ("add another log string...");

// redirect stream
_log.filepath = @"C:\another.dat";
_log.writeln_log ("add the first log string to another.dat file...");

// close
_log.close ();

类源代码：
文件： log.cs

/*
author : ez
date : 2015/4/13
describe : a class to support writing log string into logfile
*/
namespace lib_ez {

using System;
using System.Collections;
using System.Collections.Generic;

using System.IO;

public class log {

// support dynamically file path changing
public String filepath {
get { return this._logfile; }
set {
if (this._writer != null && close_file ())
this._writer = new StreamWriter (this._logfile = value, true); // support appending writing
else
open_file (this._logfile = value);
}
}

public log (String __log_file) {
this.open_file (this._logfile = __log_file);
}

public bool writeln_log (String __str) {
if (this._writer == null && !this.open_file (this._logfile))
return false;
this._writer.WriteLine (__str);
this._writer.Flush ();
return true;
/*
if (this._fs == null && ! this.open_file (this._logfile))
return false; // error in close file
writer = new StreamWriter (this._fs);
writer.WriteLine (__str);
return true;
*/
}

public static void del_log_file (String __file) {
if (File.Exists (__file))
File.Delete (__file);
}

private bool open_file (String __log_file) {
try {
this._writer = new StreamWriter (__log_file, true);
return true;
}
catch (Exception ex) {
// show exception message to Console
Console.WriteLine ("lib_ez.log.open_file [" + DateTime.Now.ToString () + "] : " + ex.Message);
return false;
}
}

// always return true
public bool close_file () {
this._writer.Dispose ();
return true;
}

private StreamWriter _writer;
private String _logfile;
}

}