Greg

SHFileOperation has a lot of detail (I had a brief look yesterday, your
link). I was looking for a pure .NET method, rather than interop - but will
go with what is needed of course. 

There is a CodeProject tip
<http://www.codeproject.com/Tips/462878/How-to-Delete-a-File-or-Folder-to-Re
cyclebin>  that may be helpful, though at the end of it he gives esentially
the same code (using the Microsoft.VisualBasic namespace) that I had in my
original post!

 

Comments to that article put a lot of doubt in my mind - the MSDN
documentation on the FOF_ALLOWUNDO constant in particular. 

 

Code straight from that article - 

 

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto, Pack = 1)]

public struct SHFILEOPSTRUCT

{

    public IntPtr hwnd;

    [MarshalAs(UnmanagedType.U4)]

    public int wFunc;

    public string pFrom;

    public string pTo;

    public short fFlags;

    [MarshalAs(UnmanagedType.Bool)]

    public bool fAnyOperationsAborted;

    public IntPtr hNameMappings;

    public string lpszProgressTitle;

}

 

[DllImport("shell32.dll", CharSet = CharSet.Auto)]

public static extern int SHFileOperation(ref SHFILEOPSTRUCT FileOp);

 

public const int FO_DELETE = 3;

public const int FOF_ALLOWUNDO = 0x40;

public const int FOF_NOCONFIRMATION = 0x10;

 

Then

 

var shf = new SHFILEOPSTRUCT();

shf.wFunc = FO_DELETE;                       //Delete the files specified in
pFrom.

shf.fFlags = FOF_ALLOWUNDO;                  //Preserve undo information, if
possible. 

shf.pFrom = @"c:\myfile.txt" + '\0' + '\0';  //File / Folder to delete

SHFileOperation(ref shf);

 

Doesn't work for me (deletes file after permssion granted; file not seen in
Recycle bin) - so, no furher progressed. 

  _____  

Ian Thomas
Victoria Park, Western Australia

 

From: [email protected] [mailto:[email protected]]
On Behalf Of Greg Keogh
Sent: Friday, October 18, 2013 7:51 AM
To: ozDotNet
Subject: Re: Problem with FileSystem.DeleteFile method in root directory

 

Ian, I saw some people interop calling the SHFileOperation function with a
SHFILEOPTSTRUCT argument. They weren't doing what you are, but this function
seems to give you total control over what happens. Maybe the fine print on
the function and struct and all the weird flag bits might explain the
behaviour you're seeing -- Greg

 

On 18 October 2013 10:14, Ian Thomas <[email protected]> wrote:

David

Re FileIOPermissions - yes, I quickly realised that it is not relevant. 

On FileSystem.DeleteFile, I think the appearance of the documentation for
different .NET versions led me to think there was change. I don't see
difference in behaviour for 3.5/4.0/4.5. 

All of the above is not really helpful to me - it doesn't allow me to
progress (well, it does mean that I don't go off on a tangent).

But I am still unable to remedy my problem. Do you have an answer, and
explanation? 

  _____  

Ian Thomas
Victoria Park, Western Australia

From: [email protected] [mailto:[email protected]]
On Behalf Of David Kean
Sent: Friday, October 18, 2013 3:06 AM
To: ozDotNet
Subject: RE: Problem with FileSystem.DeleteFile method in root directory

 

FileIOPermission has nothing to do with the problem you are hitting; it
refers to CAS-permissions which is a .NET only concept, and is used in
partial trust environments such as Hosted ASP.NET.

 

There have been zero changes in this area for .NET 4.5, are you saying you
are seeing a behavior change? These APIs delegate onto the underlying shell
implementation; so most the behavior here would be inherited from the OS
itself.

 

From: [email protected] [mailto:[email protected]]
On Behalf Of Ian Thomas
Sent: Thursday, October 17, 2013 5:31 AM
To: 'ozDotNet'
Subject: RE: Problem with FileSystem.DeleteFile method in root directory

 

Greg

I will read your link, but just now I saw at the base of the
FileSystem.Delete info, a link to the FileIOPermission Class. First, I need
to unravel the digfferences between .NET 4.5 and all the earlier releases; I
can see major changes. 

 

  _____  

Ian Thomas
Victoria Park, Western Australia

From: [email protected] [mailto:[email protected]]
On Behalf Of Greg Keogh
Sent: Thursday, October 17, 2013 8:25 PM
To: ozDotNet
Subject: Re: Problem with FileSystem.DeleteFile method in root directory

 

Ian, years ago I remember seeing a Q&A about how to NOT send things into the
recycle bin, and I vaguely recall it required a Win32 API call probably in
shell32. If you can find that call and reverse the flag it might do what you
want.

 

Wait, it might be
http://msdn.microsoft.com/en-us/library/windows/desktop/bb762164(v=vs.85).as
px, but I'm not certain.

 

Greg

 

On 17 October 2013 20:16, Ian Thomas <[email protected]> wrote:

This is situation is for a standard user on Windows 7. There is no such
problem on pre-Vista Windows versions - and I assume the Windows 8 behaviour
is similar to that on Windows 7.

I want to use the Microsoft.VisualBasic assembly's FileSystem.Delete method
universally, but can't work out how to get around the problem that the
RecycleOption.SendToRecycleBin parameter is overridden once permission is
given by the user to delete the file, when that file is in a restricted
location like the root directory. 

 

My.Computer.FileSystem.DeleteFile(TestFilePath,

                                  FileIO.UIOption.AllDialogs,

                                  FileIO.RecycleOption.SendToRecycleBin,

                                  FileIO.UICancelOption.ThrowException)

If TestFilePath is "C:\test.file" then the usual security dialog occurs, and
on continuing & giving permission the file is deleted - but permanently. 

On the otherhand, in a location like the user's desktop
 
     (Environment.GetFolderPath(Environment.SpecialFolder.Desktop) &
"\Test.txt")

it does get deleted to the recycle bin. 

How can I have the files always go to the recycle bin (assuming the user
gives permission, as required)? 

  _____  

Ian Thomas
Victoria Park, Western Australia

 

 

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