Enumerating files in .NET is easy. Everybody knows the GetFiles method and you may be tempted to write code like this :
var files = Directory.GetFiles(@"c:\windows\system32", "*.dll");
foreach (var file in files)
But if you look closer you will notice that this method returns an array of strings. This could be problematic if the directory you search contains lots of files. The method will block until it performs the search and once it finishes it will load all the results into memory. It would be much better if it just returned an IEnumerable. That’s exactly what the EnumerateFiles method does in .NET 4.0. Unfortunately in .NET 3.5 there’s nothing for the job.