Custom error trace listener: Create the trace listener class

After you create the client class, you implement the trace listener class. The trace listener derives from the CustomTraceListener class, which exposes methods for writing trace information. To create the trace listener class:

1. In Visual Studio, open the context menu of the ExternalLogging project and click Add » Class
2. Name the class file RaygunTraceListener.cs and click Add.
3. Make the RaygunTraceListener class inherit the CustomTraceListener class.
4. Define the following constructors and the fields.
   In this section of the code, you define a parameterless constructor chained to a constructor that accepts an ITraceListenerClient parameter. Although this implementation of the RaygunTraceListener uses the RaygunTraceListenerClient class that you previously created, you can easily create your own client class and pass it as a parameter in the constructor.
5. Implement the CustomTraceListener methods.
   In the code above, you check the type of the trace data that the TraceData method receives and call the Write method. The Write method then sends the information provided by the trace data to the client.

GITHUB EXAMPLE: For more information about the content of the file, see the RaygunTraceListener.cs file of the downloaded sample project.