C# - List all files in folder and sub folders

(Deutsche Version) Reading all files in a folder is pretty simple (see also C# Tipps and Tricks). If you want to do this recursively, the solution is also simple. The code I therefore use is the following:

var allfiles = System.IO.Directory.GetFiles(
  @"C:\YourFolder",  
  "*.*", 
  System.IO.SearchOption.AllDirectories);

foreach (string file in allfiles) {}

To filter this result, you can add a .Where at the end, the following code will only list audio files:

var allfiles = System.IO.Directory.GetFiles( 
  @"C:\YourFolder", 
  "*.*", 
  System.IO.SearchOption.AllDirectories).Where(
    s => s.EndsWith(".mp3") || 
    s.EndsWith(".wav") || 
    s.EndsWith(".wma"));  

foreach (string file in allfiles) {}