Check if part of file name exists in a path using .net - vb.net

Question

I would like to check in my weapplication if a file exists in a path provided. File name can be anything eg:pic.jpg, pic.txt,pic1.txt,pic2.jpg etc.
I need to check if "pic" name exists in the path.Only check if 'pic' exists or pic+anything+.jpg or pic.anything.txt exists using vb.net.
Please help.

Answer 1

You'll want to check the File.Exists method. Don't forget, this only work for finding files on the server, not the client. Finding a file on the client side is a totaly different mather.

Answer 2

You can get the list of files in the given directory and then check the filenames to see if the fragment of text you're looking for is in any of them. Assuming you want to include the extension in the test and you don't care if it is upper or lower case:
Function FilenameFragmentExists(srcDir As String, fragment As String) As Boolean
Dim files() As String = IO.Directory.GetFiles(srcDir)
Dim found As Boolean = False
For i = 0 To files.Length - 1
If IO.Path.GetFileName(files(i)).IndexOf(fragment, StringComparison.OrdinalIgnoreCase) > -1 Then
found = True
Exit For
End If
Next
Return found
End Function
Or you can do it in one line with LINQ, and if you are using .NET framework >=4 then you can use .EnumerateFiles instead of .GetFiles, which has a chance of being faster:
Function FilenameFragmentExists(srcDir As String, fragment As String) As Boolean
Return IO.Directory.EnumerateFiles(srcDir).Any(Function(f) IO.Path.GetFileName(f).IndexOf(fragment, StringComparison.OrdinalIgnoreCase) >= 0)
End Function

Answer 3

You should use Directory.GetFiles(path, pattern) to check if it returns some files corresponding to your pattern. For example
Dim files = Directory.GetFiles("C:\temp", "*.jpg")
if files.Length > 0 Then
Console.WriteLine("Directory contains " + files.Length + " with the required pattern")
Else
Console.WriteLine("Directory doesn't contain any file with the required pattern")
End if
In the second parameter you could pass any kind of pattern following the usual wildcard rules used for directory listing