Serilog printing contextual property - serilog

Question

I am using Serilog and want to print some information message that contains contextual property.
For example:
var logger = Log.ForContext("FirstName", "Yosi");
logger.Information("Hello {FirstName}")
and this works as expected, but when I add parameter to the log message it self, I get unexpected result.
var logger = Log.ForContext("FirstName", "Yosi");
logger.Information("Hello {FirstName} {LastName}", "Attias")
I expect the result to be:
Hello Yosi Attias
but I get:
Hello Attias {LastName}
Is there a fix for that? am I missing something? or this is a bug?

Answer 1

Message templates are only evaluated against the parameters that are passed in to the logging method. Log statements are intended to work consistently regardless of any other configuration/context in the program.
If you want to add additional properties to the logging output, add them to the outputTemplate argument of whatever sink you are configuring:
Log.Logger = new LoggerConfiguration()
.WriteTo.ColoredConsole(outputTemplate:
"{Timestamp:HH:mm} [{Level}] ({LastName}) {Message}{NewLine}{Exception}")
.CreateLogger();

Answer 2

use refection to add properties and their values automatically to log them all in Serilog:
public static Task GenericLog(MyClassLog myclassLog, string message=null)
{
if (string.IsNullOrEmpty(message)) message = nameof(myclassLog);
var properties = typeof(MyClassLog).GetProperties();
var propertyEnrichers = new PropertyEnricher[properties.Length];
for (int i = 0; i < properties.Length; i++)
propertyEnrichers[i] =
new PropertyEnricher(
properties[i].Name,
properties[i].GetValue(myclassLog)
);
var withProps = Log.ForContext(propertyEnrichers);
withProps.Debug(message);
return Task.CompletedTask;
}