推荐订阅源

写入Listeners集合
  Write 
  WriteLine
  WriteIf
  WriteLineIf
  Assert 如果布尔表达式微False,将断言信息写入Listeners,并显示消息框
  Fail 直接将断言信息写入Listeners,并显示消息框
 
  Indent,Unindent 设置缩进程度

输出记录到文本
System.IO.FileStream myLog = new System.IO.FileStream("C:\\aaa.txt",System.IO.FileMode.OpenOrCreate);
TextWriterTraceListener myListener = new TextWriterTraceListener(myLog);
Tace.Listeners.Add(myListener);

要将输出结果实际写入文件必须调用Flush()刷新缓冲区
也可设置AutoFlush = True;

输出记录到EventLog
EventLog myLog = new EventLog("Debug Log");
myLog.Source = "Trace Output";
EventLogTraceListener myListener = new EventLogTraceListener(myLog);

使用Trace开关
BooleanSwitch myBooleanSwitch = new BooleanSwitch("Switch1","Controls Data Tracing");
TraceSwitch myTraceSwitch = new TraceSwitch("Switch2","Controls Form1 Tracing");

TraceSwitch有5种级别
TraceLevel.Off             0  关闭
TraceLevel.Error          1  很简短的错误信息
TraceLevel.Warning     2  错误消息和警告
TraceLevel.Info            3  错误消息、警告、简短消息
TraceLevel.Verbose     4  消息、警告、描述

4种属性
TraceSwitch.TraceError
TraceSwitch.TraceWarning
TraceSwitch.TraceInfo
TraceSwitch.TraceVerbose

使用开关
Trace.WriteIf(myBooleanSwitch.Enabled== true,"Error");
Trace.WriteIf(myTraceSwitch.TraceInfo == true, "type error");
 
在config文件中配置
<system.diagnostics>
     <switches>
         <add name="myBooleanSwitch" value="0" />
         <add name="myTraceSwitch" value="3" />
     </switches>
</system.diagnostics>