Unable to delete all files from temporary folders in vb.net - vb.net

Question

I am using the following code to delete all files from a particular folder:
Sub DeleteFiles(Folder As String)
If Directory.Exists(Folder) Then
For Each _file As String In Directory.GetFiles(Folder)
File.Delete(_file)
Next
For Each _folder As String In Directory.GetDirectories(Folder)
DeleteFiles(_folder)
Next
End If
End Sub
Whenever I use the above code to delete all files from "C:\Temp" by calling it using DeleteFiles("C:\Temp"), It deletes all the files successfully, but whenever I try to use the same code for deleting files in "C:\Windows\TEMP\", it breaks the operation saying that the file is in use. I want that the code should not raise an exception and stop deleting the files right-away. If the file cannot be deleted, the code should move on to the next file and try deleting it. This way, it should be able to delete maximum possible files from that directory.

Answer 1

You need to handle exceptions raised by File.Delete() using a Try....Catch... statement. I'm not a VB coder (I'm surprised to find myself answering this question), but something like this should work:
Sub DeleteFiles(Folder As String)
If Directory.Exists(Folder) Then
For Each _file As String In Directory.GetFiles(Folder)
Try
File.Delete(_file)
Catch e As System.IO.IOException
Console.WriteLine(e.Message)
End Try
Next
For Each _folder As String In Directory.GetDirectories(Folder)
DeleteFiles(_folder)
Next
End If
End Sub
This will catch an System.IO.IOException exception, log that it was received, and then ignore it. Note that this will catch a number of other File.Delete() related exceptions such as System.IO.DirectoryNotFoundException, System.IO.PathTooLongException, etc. If you want to catch these, you must add a Catch clause for each before the more general System.IO.IOException. The possible exceptions are listed here, along with an example of using File.Delete() - you just need to read the docs.
You might like to also look at Directory.Delete to recursively delete a directory, its files, and its subdirectories.

Answer 2

You can't stop an exception being thrown. What you need to do is catch the exception, process it as appropriate (which may mean just ignoring it) and move on. That means putting a Try...Catch block inside your first loop. That way, when File.Delete throws an exception, you can catch it, ignore it and the loop will continue.
Be sure to catch only the type of exception that you expect to be thrown though. Otherwise, something completely unexpected may be causing an issue and you're just ignoring it, which is bad. Only ignore exceptions that you reasonably expect and know can be safely ignored.

Answer 3

Dim temp As String = Environment.GetEnvironmentVariable("TEMP")
Dim k As String() = System.IO.Directory.GetFiles(temp)
Dim i As Integer
For i = 0 To k.Length
On Error Resume Next
Kill(k(i))
System.IO.File.Delete(k(i))
Next