Logging from powershell-script to csharp-program (log4net - logfile)

Question

I have written a program with C#, that creates a logfile and fills this by using log4net. This program starts powershell-scripts. The scripts should use log4net, too. I want

Answer 1

As an alternative you could reroute the streams and use the standard Write-Error, Write-Verbose, etc. CMDlets in your Script.

In your C# app attach methods to the streams events, like so:

PowerShell ps = PowerShell.Create();
// ... code to add your script, etc.
ps.Streams.Warning.DataAdded += new EventHandler(Warning_DataAdded);
// ... attach more streams for other log levels
ps.Invoke();

Create your methods like so:

static void Warning_DataAdded(object sender, DataAddedEventArgs e)
{
    PSDataCollection warningStream = (PSDataCollection)sender;
    log.Warn(warningStream[e.Index].Message);
}

This should write everything you output in your PowerShell Script via

Write-Warning "This is a warning message"

to the Warn level in log4net.