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_
If the matching requirements are simple, try:
string[] matchingFiles = System.IO.Directory.GetFiles( path, "*ABC123*" );
If they require something more complicated, you can use regular expressions (and LINQ):
string[] allFiles = System.IO.Directory.GetFiles( path, "*" );
RegEx rule = new RegEx( "ABC[0-9]{3}" );
string[] matchingFiles = allFiles.Where( fn => rule.Match( fn ).Success )
.ToArray();