Title: File Operations the 32-bit way
Question: This article shows how to use the SHFileOperation to get dirty file work done the easy way. The SHFileOperation is a function supplied by Windows 95/98/NT4/2000/ME to get most jobs fast done.
Answer:
The DoFileWork procedure shown below, will help you to get most basic file work done by using the Win32 Shell API function: SHFileOperation.
The syntax of the function is:
function DoFileWork(aWnd: HWND; aOperation: UINT;
aFrom, aTo: array of string; aFlags: FILEOP_FLAGS): Integer;
The following example could be one way of calling:
DoFileWork(Self.Handle, FO_DELETE, strlFiles, nil, FOF_ALLOWUNDO);
This would move all files in the String List strlFiles to the trash can.
Parameters:
aWnd - Handle of the calling Window (Form)
aOperation - anyone of the following
FO_MOVE
FO_COPY
FO_DELETE
FO_RENAME (Works on one file at a time, only)
aFrom - List of the files that are to be worked on (fully qualifed
file names!)
aTo - List of the new file names (must be nil for FO_DELETE)
aFlags - a combination among the following
FOF_ALLOWUNDO - Preserve undo information
FOF_FILESONLY - Do not apply to directories
FOF_MULTIDESTFILES - aTo specifies a file for every file
in the aFrom list
FOF_NOCONFIRMATION - User is not asked to press the yes
button
FOF_NOERRORUI - Do not display error messages
FOF_NORECURSION - Do not parse sub-folders
FOF_RENAMEONCOLLISION - Create a new file name if one
with same exists already
FOF_SILENT - Do not display a progress dialog
There are more flags, however, these are the most important ones.
Result:
- 0 on success
- nonzero if error occured
NOTE: you must include the ShellAPI unit in your uses clause!
function DoFileWork(
aWnd: HWND;
aOperation: UINT;
aFrom, aTo: TStrings;
aFlags: FILEOP_FLAGS
): Integer;
var
I: Integer;
FromPath, ToPath: string;
SHFileOpStruct: TSHFileOpStruct;
begin
FromPath := '';
for I := 0 to aFrom.Count - 1 do
FromPath := FromPath + aFrom.Strings[I] + #0;
FromPath := FromPath + #0;
if Assigned(aTo) then
begin
ToPath := '';
for I := 0 to aTo.Count - 1 do
ToPath := ToPath + aTo.Strings[I] + #0;
ToPath := ToPath + #0;
end;
with SHFileOpStruct do
begin
Wnd := aWnd;
wFunc := aOperation;
pFrom := PChar(FromPath);
if Assigned(aTo) then
begin
pTo := PChar(ToPath)
end else begin // target available
pTo := nil;
end; // target not available
fFlags := aFlags;
end; // structure
Result := SHFileOperation(SHFileOpStruct);
end;