Ok, thnx a lot! Got it working. This is how I implemented it:
I'm curious, is there a way in WPF to have a simple multi line text box without layout ect? I've messed around with textbox and textarea a little but didn't manage to achieve this.
string rtbContents = new TextRange(rtbPaths.Document.ContentStart, rtbPaths.Document.ContentEnd).Text;
foreach (string line in rtbContents.Split('\n'))
String trimmedLine = line.Trim(' ', '\r');
if (trimmedLine.Length > 0)