记录asp.net网站是什么原因导致停止运行的代码

protected void Application_End(object sender, EventArgs e)
{
RecordEndReason();
}

/// <summary>
/// 记录网站停止运行原因
/// </summary>
protected void RecordEndReason()
{
HttpRuntime runtime = (HttpRuntime)typeof(System.Web.HttpRuntime).InvokeMember("_theRuntime", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.GetField,
null,
null,
null);
if (runtime == null)
return;
string shutDownMessage = (string)runtime.GetType().InvokeMember("_shutDownMessage",
System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.GetField,
null,
runtime,
null);
string shutDownStack = (string)runtime.GetType().InvokeMember(
"_shutDownStack",
System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.GetField,
null,
runtime,
null);
string reasonString="网站Application_End，停止运行,shutDownMessage=" + shutDownMessage + ",shutDownStack=" + shutDownStack;
LogHelper.WriteErrorLog(reasonString,null);
LogHelper.WriteSmtp(reasonString, null);
//以下方法将重启的原因和重启时的堆栈信息记录到了windows的事件查看器中,你也可以记录到文本文件中。
//EventLog log = new EventLog();
//log.Source = "ASP.NET 2.0.50727.0";
//log.WriteEntry(String.Format("\r\n\r\n_shutDownMessage={0}\r\n\r\n_shutDownStack={1}", shutDownMessage, shutDownStack), EventLogEntryType.Information);
}