Check Security Privileges on Folder Before Adding to TreeView

Question

Greetings I have an Explorer style Form (vb.net) with a TreeView and ListView. All network drives are added as nodes to the TreeView with their folders as child nodes. However when the application comes across a folder to which is does not have access privileges an error is thrown. The user get a Windows prompt to Continue or Quit. Clicking continue stops the sub that adds the nodes to the TreeView. For example if there are 10 folders but the fifth folder cannot be accessed then only the first five folders are added to the TreeView and the fifth one will not have any children because the folder can't be opened. Does anyone know a way that I can check the security privileges for a folder without opening the folder so that I can skip over any folders that my application cannot access thereby avoiding the error? Please note: changing access privileges to allow my application to access all the folders is not an option. Thanks!

PJ Martins · Answer

You can check the attributes of folders using the System.IO.DirectoryInfo class. Dim dinf As New System.IO.DirectoryInfo(  > ) If Not dinf.Attributes = IO.FileAttributes.ReadOnly Then ... End If

PJ Martins · Answer

Unfortunately your solution to check for System.UnauthorizedAccessException is the best one you can try .GetAccessControl() but it might give you the same exception.

Sean Westerfield · Answer

Thanks a lot for the reply! I tried this option but it doesn't seem to work for me. The folders I'm checking are not just Read Only they are completely inaccessible. I've looked to see if there is another attribute that would be the equivalent of No Access but I can't find anything. The only workaround I've found so far is to set up a separate function which tries to access the contents of the directory and then returns True if it succeeds and false if the System.UnauthorizedAccessException is thrown. If false then the directory is not added to the TreeView. It seems to work but it seems like there should be a simpler way. Thanks again!