* VB-CODE (2)
Tip 176: Sending Files to the Recycle Bin in Visual Basic 4.0

December 5, 1995

Abstract
When using the Microsoft? Windows? 95 operating system, you can delete a
file from disk by dragging the file or sending the file to the Recycle
Bin. The file is not actually removed from disk but is only marked for
deletion by the system. When the Recycle Bin is emptied, however, the file
is physically removed from the disk. This article explains how to send
files to the Recycle Bin in a Microsoft Visual Basic? version 4.0
application.

Using the SHFileOperation Function to Delete Files
When you use the Microsoft? Windows? 95 operating system, any files that
you delete are stored in the Recycle Bin. The files are not physically
removed from the disk, but they appear to have been deleted. If you want,
the files (or directories) that you have moved to the Recycle Bin can be
restored and thus again be made available. However, if you want to
physically remove the files stored in the Recycle Bin from your hard disk,
you must empty the Recycle Bin. After the Recycle Bin has been emptied,
you cannot recover the deleted files. The space occupied by the deleted
files is also freed.

In a Microsoft Visual Basic? version 4.0 application, you can send files
to the Recycle Bin by calling the Windows application programming
interface (API) SHFileOperation function. This function lets you
manipulate files by moving, copying, renaming, or deleting them.

The SHFileOperation function requires a pointer to a SHFILEOPSTRUCT
structure that contains the name(s) of the file(s) you want to perform
an operation on, as well as the type of operation (for example, deleting
a file) you want to carry out.

When deleting multiple filenames, each filename specified in the
SHFILEOPSTRUCT structure must be separated by a NULL character. The
entire list of filenames must be terminated by two consecutive NULL
characters.

The fFlags field in the SHFILEOPSTRUCT structure must be set to the
operation you want to perform on the selected file(s). In this case,
set this field to FO_DELETE, which tells the operating system that you
want to delete the file by sending it to the Recycle Bin. In addition,
because you are sending the file to the Recycle Bin, use the FOF_ALLOWUNDO
flag. This flag preserves the information required to undelete a file
should you later decide not to physically remove the file from the hard
disk.

Example Program
This program shows how to send files to the Recycle Bin in Windows 95.

 1. Create a new project in Visual Basic. Form1 is created by default.
 2. Add the following code to the General Declarations section of Form1
    (note that the Declare statement must be typed as a single line of
    code):

Public Const FO_DELETE = &H3
Public Const FOF_ALLOWUNDO = &H40
Declare Function SHFileOperation Lib "shell32.dll" Alias "SHFileOperationA"
   (lpFileOp As SHFILEOPSTRUCT) As Long

 3. Create a new function called ShellDelete. Add the following code to
    this function:

Public Function ShellDelete(ParamArray vntFileName() As Variant)
    Dim I As Integer
    Dim sFileNames As String
    Dim SHFileOp As SHFILEOPSTRUCT

    For I = LBound(vntFileName) To UBound(vntFileName)
        sFileNames = sFileNames & vntFileName(I) & vbNullChar
    Next

    sFileNames = sFileNames & vbNullChar

    With SHFileOp
        .wFunc = FO_DELETE
        .pFrom = sFileNames
        .fFlags = FOF_ALLOWUNDO
    End With

    ShellDelete = SHFileOperation(SHFileOp)
End Function

 4. Add a Command Button control to Form1. Command1 is created by default.
 5. Add the following code to the Click event for Command1:

Private Sub Command1_Click()
    Dim FileToKill As String

    FileToKill = "c:\test*.txt"
    ShellDelete FileToKill
    MsgBox "File(s) deleted"
End Sub

 6. From the Visual Basic Insert menu, select Module to create a new
    module. MODULE1.BAS is created by default.
 7. Add the following TYPE structure to MODULE1.BAS:

Type SHFILEOPSTRUCT
    hWnd As Long
    wFunc As Long
    pFrom As String
    pTo As String
    fFlags As Integer
    fAborted As Boolean
    hNameMaps As Long
    sProgress As String
End Type

Run the example program by pressing F5. Click the Command Button control.
A dialog box appears, asking whether you really want to delete the
selected files. (All files with the name TEST*.TXT stored in the root
directory of the hard drive will be deleted.) Click the Yes button to
confirm the delete request.

Additional References

"Managing the Recycle Bin to Free Disk Space." (Library, Product
   Documentation, SDKs, Windows Resource Kit, Windows 95 Resource Kit,
   Part 5 System Configuration, Chapter 20 Disks and File Systems,
   Partitioning Hard Disks)
"Recycle Bin Integration." (Library, Specifications, Windows Guidelines,
   Windows Interface Guidelines for Software Design, Integrating with the
   System, Taskbar Integration)
"SHFileOperation QuickInfo." (Library, Product Documentation, SDKs,
   Win32 SDK, Win32 Programmer's Reference, Reference, Functions,
   SetStretchBitMode to ShowCaret)
"SHFILEOPSTRUCT QuickInfo." (Library, Product Documentation, SDKs,
   Win32 SDK, Win32 Programmer's Reference, Reference, Structures,
   REOBJECT to TOKEN PRIVILEGES)