How to do logging with WPF?

Question

I'm writing a WPF application using a MVVM pattern and using Prism in selected places for loose coupling, and I'd like to have logging messages shown in a window and written to a file. The subset of messages going each way may not be the same.

I think I should publish a message through the EventAggregator (MS-Prism implementation of observer pattern) and have two objects subscribe: one that updates the LogWindowViewModel and one that logs using the Enterprise Library logger. Is this a good idea or am I duplicating something that's already implemented?

Answer 1

The fact that the log message will be different in each output is the limiting factor.

Extending the block may suffice and defining a CustomTraceListener or ILogFilter may work out for you. This would avoid needing to use the EventAggregator .

It boils down to who has the knowledge of what and where to log. Are the differences driven off values within the logging engine such as severity? Are they instead driven by the consumer of the logging engine and therefore tightly coupled to the class itself? These types of questions will dictate your choice.

Leveraging the extension points in the logging block would be my first choice before having to rely on using the EventAggregator .

Answer 2

I think an idea is fine. There is not so much functionality to be duplicated it seems

Answer 3

我使用Common.Logging作为数据收集器，过滤器和分配器，用于可比较的东西，并为我自己的处理和ui输出编写了一个自定义appender。