If I want to check how many files there are in a folder (where there is likely to be 10,000+ files), is there a more efficient way than...
Public Function FileCount(FolderName as String) As Integer
Dim Files() As String
Files = IO.Directory.GetFiles(FolderName)
Return Files.Length
End Function
It seems to be unweildly to be forced to load such a potentially large array. Any better suggestions?
No I think
But you can return IO.Directory.GetFiles(FolderName).Length
Has it caused a problem? It's not like GetFiles() is returning the contents of each file, it is returning to you their paths, i.e., a string array.
It may be unweildy but if you run a test and find the performance impact is minimal, it might still be the appropriate solution.
I don't think it's a problem. Under the hood the files aren't opened anyway, the function call only queries the disk file index or file allocation table for the files under that folder. It's no different than doing a dir on the command prompt.
Best way to see if it really causes a problem is to profile it.
Unfortunately, you can't enumerate the contents of a directory in .NET 3.5 without using interop or obtaining all of the paths ahead of time. As mentioned, the disadvantage to using File.GetFiles() is that it returns all the paths at once, which can consume more resources than required.
If you want to enumerate the contents of the directory and increment a counter as you enumerate, you may try one of the following options.
IEnumerable<T> for enumerating the contents of a directory.Whenever interop is used, you should be concerned about the performance of making native WinAPI calls from managed code. Consider utilizing a profiler to determine if the performance penalty is acceptable.