This article was previously published under Q151799
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The Windows API provides the ability to perform a copy, move, rename, ordelete operation on a file system object using the SHFileOperation APIfunction exported by Shell32.dll. This article shows how to copy a list offiles into a named folder while displaying a dialog box with a copyanimation and an animated scroll bar displayed to show the progress of thecopy operation. The article also shows how to create a sample project thatdemonstrates how the use of this API function.
The SHFileOperation function provides the ability to move, rename, ordelete file system objects based on the flags passed to the function. Thefunction requires the address of the SHFILEOPSSTRUCT structure. Thisstructure 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-wordboundaries, but some API functions, such as the SHFileOperation, expect thedata to arrive as byte-aligned. If you pass the SHFILEOPSTRUCT structurewithout taking this double-word boundary into consideration, thefAnyOperationsAborted, hNameMappings, and the lpszProgressTitle members ofthe structure will not be passed correctly. If you want the copy dialog boxto contain a custom message string as defined by the lpszProgressTitlemember, use a byte array to work around this limitation. The use of a bytearray is demonstrated in the sample project.
The next section shows you how to create a sample project that demonstrateshow to use the SHFileOperation function to copy the Visual Basic executablefile and a Help file to a test folder. The sample project also shows youhow to display a custom message string in the dialog box that displays theprogress information.
Start a new Standard EXE project in Visual Basic. Form1 is created by default.
Add the two check boxes and one 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 = Environ("windir") & "\*.exe" .fFlags = FOF_SIMPLEPROGRESS Or FOF_FILESONLY Else .pFrom = Environ("windir") & "\Explorer.exe" _ & vbNullChar _ & Environ("windir") & "\WinHelp.exe" _ & 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
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.
SHFileOperation and SHFILEOPSTRUCT in the Platform SDK productdocumentation
Err Object topic in the Microsoft Visual Basic Language Reference