Log stream does not pick up messages

Question

In ASP.NET Core application I added the following to the controller action

System.Diagnostics.Trace.WriteLine("Wrote log at " + DateTime.Now.ToLongTimeString());
System.Diagnostics.Trace.TraceError("Wrote error log at " + DateTime.Now.ToLongTimeString());
System.Diagnostics.Trace.TraceInformation("Wrote info log at " + DateTime.Now.ToLongTimeString());

I enabled Application Logging (Filesystem) under Diagnostic Logs menu in Azure, but under Log Stream I do not see any of my trace messages. Am I missing something?

Update

I created a sample MVC application using the .NET Framework (instead of .NET Core) and Log Stream works fine when I use System.Diagnostics.Trace to output messages.

Does this mean I cannot use System.Diagnostics.Trace in .NET Core to output messages to Log Stream? This works in Visual Studio to output messages to Output window.

Answer 1

As per Logging in ASP.NET Core

Navigate to the Log Streaming page to view application messages. They're logged by application through the ILogger interface.

In the ASP.NET Core app I injected the logger in the Controller:

private readonly ILogger _logger;
public HomeController(ILogger<HomeController> logger)
{
    _logger = logger;
}

And now can use it in Controller actions.

_logger.LogWarning(100, "Warning using ILogger");

And now these logs show up on Log Streaming page in Azure web app.