asp.net – 在Global.asax中使用Trace

从您链接到的MSDN页面(强调我的)：

Although ASP.NET displays trace messages whenever tracing is enabled
for a page,System.Diagnostics trace messages are written only when
the code in which the trace messages reside is compiled by using an
explicit compiler switch—the TRACE switch. In other words,if you do
not explicitly compile the AuthorClass using the TRACE switch,you
will not see the trace messages,even with the WebPageTraceListener
added.

You can configure your application to automatically compile using the
TRACE switch,by adding a new section to your Web.config file.

这是应放在< system.diagnostics>之后的Web.config条目.部分：

<system.codedom>
  <compilers>
    <compiler language="c#;cs;csharp" 
              extension=".cs" 
              compilerOptions="/d:TRACE"
              type="Microsoft.CSharp.CSharpCodeProvider,System,Version=2.0.3500.0,Culture=neutral,PublicKeyToken=b77a5c561934e089" warningLevel="1" />
    <compiler language="VB"
              extension=".vb" 
              compilerOptions="/d:Trace=true"
              type="Microsoft.VisualBasic.VBCodeProvider,Version=1.0.5000.0,PublicKeyToken=b77a5c561934e089" />
  </compilers>
</system.codedom>