How to collect all files in a Folder and its Subfolders that match a string

Question

In C# how can I search through a Folder and its Subfolders to find files that match a string value. My string value could be \"ABC123\" and a matching file might be ABC123_

Answer 1

From memory so may need tweaking

class Test
{
  ArrayList matches = new ArrayList();
  void Start()
  {
    string dir = @"C:\";
    string pattern = "ABC";
    FindFiles(dir, pattern);
  }

  void FindFiles(string path, string pattern)
  {
    foreach(string file in Directory.GetFiles(path))
    {
      if( file.Contains(pattern) )
      {
        matches.Add(file);
      }
    }
    foreach(string directory in Directory.GetDirectories(path))
    {
      FindFiles(directory, pattern);
    }
  }
}