The information in this article applies to:
- Microsoft Visual Basic Learning, Professional, and Enterprise Editions
for Windows, version 5.0
- Microsoft Visual Basic Standard, Professional, and Enterprise Editions,
32-bit only, for Windows, version 4.0
SUMMARY
The Windows API provides the ability to perform a copy, move, rename, or
delete operation on a file system object using the SHFileOperation API
function exported by Shell32.dll. This article shows how to copy a list of
files into a named folder while displaying a dialog box with a copy
animation and an animated scroll bar displayed to show the progress of the
copy operation. The article also shows how to create a sample project that
demonstrates how the use of this API function.
MORE INFORMATION
The SHFileOperation function provides the ability to move, rename, or
delete file system objects based on the flags passed to the function. The
function requires the address of the SHFILEOPSSTRUCT structure. This
structure contains the following members:
- hwnd - Window handle to the dialog box to display information about the
status of the file operation.
- wFunc - the operation to perform, as defined by one of the following
values:
- FO_COPY - Copies the files specified in the pFrom member to the
location specified in the pTo member.
- FO_DELETE - Deletes the files specified in pFrom. (pTo is ignored.)
- FO_MOVE - Moves the files specified in pFrom to the location
specified in pTo.
- FO_RENAME - Renames the files specified in pFrom.
- pFrom - Address of a buffer to specify one or more source file names.
Multiple names must be null-separated. The list of names must be double
null-terminated.
- pTo - Address of a buffer to contain the name of the destination file or
directory. The buffer can contain multiple destination file names if the
fFlags member specifies FOF_MULTIDESTFILES. Multiple names must be
null-separated. The list of names must be double null-terminated.
- fFlags - Flags that control the file operation. This member can be a
combination of the following flags:
- FOF_ALLOWUNDO - Preserve Undo information, if possible.
- FOF_CONFIRMMOUSE - Not currently implemented.
- FOF_FILESONLY - Perform the operation on files only if a wildcard
file name (*.*) is specified.
- FOF_MULTIDESTFILES - The pTo member specifies multiple destination
files (one for each source file) rather than one directory where all
source files are to be deposited.
- FOF_NOCONFIRMATION - Respond with Yes to All for any dialog box that
is displayed.
- FOF_NOCONFIRMMKDIR - Does not confirm the creation of a new directory
if the operation requires one to be created.
- FOF_NOERRORUI - No user interface will be displayed if an error
occurs.
- FOF_RENAMEONCOLLISION - Give the file being operated on a new name in
a move, copy, or rename operation if a file with the target name
already exists.
- FOF_SILENT - Does not display a progress dialog box.
- FOF_SIMPLEPROGRESS - Displays a progress dialog box but does not show
the file names.
- FOF_WANTMAPPINGHANDLE - If FOF_RENAMEONCOLLISION is specified, the
hNameMappings member will be filled in if any files were renamed.
- fAnyOperationsAborted - Value that receives TRUE if the user aborted any
file operations before they were completed, or FALSE otherwise.
- hNameMappings - Handle to a file name mapping object that contains an
array of SHNAMEMAPPING structures. Each structure contains the old and
new path names for each file that was moved, copied, or renamed. This
member is used only if the fFlags member includes the
FOF_WANTMAPPINGHANDLE flag. The handle must be freed by using the
SHFreeNameMappings function.
- lpszProgressTitle - Address of a string to use as the title of a
progress dialog box. This member is used only if fFlags includes the
FOF_SIMPLEPROGRESS flag.
NOTE: The 32-bit version of Visual Basic aligns structures at double-word
boundaries, but some API functions, such as the SHFileOperation, expect the
data to arrive as byte-aligned. If you pass the SHFILEOPSTRUCT structure
without taking this double-word boundary into consideration, the
fAnyOperationsAborted, hNameMappings, and the lpszProgressTitle members of
the structure will not be passed correctly. If you want the copy dialog box
to contain a custom message string as defined by the lpszProgressTitle
member, use a byte array to work around this limitation. The use of a byte
array is demonstrated in the sample project.
The next section shows you how to create a sample project that demonstrates
how to use the SHFileOperation function to copy the Visual Basic executable
file and a Help file to a test folder. The sample project also shows you
how to display a custom message string in the dialog box that displays the
progress information.
Step-by-Step Example
- Start a new Standard EXE project in Visual Basic. Form1 is created by
default.
- Add the two check boxes and on CommandButton to the Form1 form.
- Copy the following code to the Code window of the Form1 form:
Option Explicit
Private Const FO_COPY = &H2& 'Copies the files specified
'in the pFrom member to the
'location specified in the
'pTo member.
Private Const FO_DELETE = &H3& 'Deletes the files specified
'in pFrom (pTo is ignored.)
Private Const FO_MOVE = &H1& 'Moves the files specified
'in pFrom to the location
'specified in pTo.
Private Const FO_RENAME = &H4& 'Renames the files
'specified in pFrom.
Private Const FOF_ALLOWUNDO = &H40& 'Preserve Undo information.
Private Const FOF_CONFIRMMOUSE = &H2& 'Not currently implemented.
Private Const FOF_CREATEPROGRESSDLG = &H0& 'handle to the parent
'window for the
'progress dialog box.
Private Const FOF_FILESONLY = &H80& 'Perform the operation
'on files only if a
'wildcard file name
'(*.*) is specified.
Private Const FOF_MULTIDESTFILES = &H1& 'The pTo member
'specifies multiple
'destination files (one
'for each source file)
'rather than one
'directory where all
'source files are
'to be deposited.
Private Const FOF_NOCONFIRMATION = &H10& 'Respond with Yes to
'All for any dialog box
'that is displayed.
Private Const FOF_NOCONFIRMMKDIR = &H200& 'Does not confirm the
'creation of a new
'directory if the
'operation requires one
'to be created.
Private Const FOF_RENAMEONCOLLISION = &H8& 'Give the file being
'operated on a new name
'in a move, copy, or
'rename operation if a
'file with the target
'name already exists.
Private Const FOF_SILENT = &H4& 'Does not display a
'progress dialog box.
Private Const FOF_SIMPLEPROGRESS = &H100& 'Displays a progress
'dialog box but does
'not show the
'file names.
Private Const FOF_WANTMAPPINGHANDLE = &H20&
'If FOF_RENAMEONCOLLISION is specified,
'the hNameMappings member will be filled
'in if any files were renamed.
' The SHFILOPSTRUCT is not double-word aligned. If no steps are
' taken, the last 3 variables will not be passed correctly. This
' has no impact unless the progress title needs to be changed.
Private Type SHFILEOPSTRUCT
hwnd As Long
wFunc As Long
pFrom As String
pTo As String
fFlags As Integer
fAnyOperationsAborted As Long
hNameMappings As Long
lpszProgressTitle As String
End Type
Private Declare Sub CopyMemory Lib "KERNEL32" _
Alias "RtlMoveMemory" _
(hpvDest As Any, _
hpvSource As Any, _
ByVal cbCopy As Long)
Private Declare Function SHFileOperation Lib "Shell32.dll" _
Alias "SHFileOperationA" _
(lpFileOp As Any) As Long
Private Sub Form_Load()
Check1.Caption = "Copy All Files in VB Directory"
Check2.Caption = "Display Custom Message"
Command1.Caption = "Copy Files"
End Sub
Private Sub Command1_Click()
Dim result As Long
Dim lenFileop As Long
Dim foBuf() As Byte
Dim fileop As SHFILEOPSTRUCT
lenFileop = LenB(fileop) ' double word alignment increase
ReDim foBuf(1 To lenFileop) ' the size of the structure.
With fileop
.hwnd = Me.hwnd
.wFunc = FO_COPY
' The files to copy separated by Nulls and terminated by two
' nulls
If Check1.Value = vbChecked Then
.pFrom = "C:\Program Files\DevStudio\VB\*.*" & vbNullChar
_
& vbNullChar
.fFlags = FOF_SIMPLEPROGRESS Or FOF_FILESONLY
Else
.pFrom = "C:\PROGRAM FILES\DEVSTUDIO\VB\VB5.EXE" _
& vbNullChar _
& "C:\PROGRAM FILES\DEVSTUDIO\VB\README.HLP" _
& vbNullChar _
& vbNullChar
End If
.pTo = "C:\testfolder\" & vbNullChar & vbNullChar
If Check2.Value = vbChecked Then
.fFlags = FOF_SIMPLEPROGRESS Or FOF_NOCONFIRMATION Or _
FOF_NOCONFIRMMKDIR
.lpszProgressTitle = "Your custom dialog string " & _
"appears here." & vbNullChar _
& vbNullChar
End If
End With
' Now we need to copy the structure into a byte array
Call CopyMemory(foBuf(1), fileop, lenFileop)
' Next we move the last 12 bytes by 2 to byte align the data
Call CopyMemory(foBuf(19), foBuf(21), 12)
result = SHFileOperation(foBuf(1))
If result <> 0 Then ' Operation failed
MsgBox Err.LastDllError 'Show the error returned from
'the API.
Else
If fileop.fAnyOperationsAborted <> 0 Then
MsgBox "Operation Failed"
End If
End If
End Sub
4. On the Run menu, click Start or press the F5 key to start the program.
Click Copy Files to start the copy process. To copy all the files in the
Visual Basic program directory, check Copy All Files in VB Directory. To
show where a custom message will display in the dialog box that shows
the copy progress, check Display Custom Message.
NOTE: On faster machines the dialog may not be displayed because the
copy Operation completes before the dialog is shown. Select the Copy All
Files option to guarantee that the dialog will be displayed.
REFERENCES
SHFileOperation and SHFILEOPSTRUCT in the Platform SDK product
documentation
Err Object topic in the Microsoft Visual Basic Language Reference
Keywords : APrgOther vb432 VB4WIN vb5all vb5howto vbwin
Version : WINDOWS:4.0,5.0
Platform : WINDOWS
Issue type : kbhowto
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