Getting windows ‘ShFileOperation’ API to recursively delete files in Delphi

Question

Hi

I am using the following code to delete a large number of files

function FastDelete(const fromDir: string): Boolean;
var
  fos: TSHFileOpStruct;
begin
  ZeroMemory(@fos, SizeOf(fos));
  with fos do
  begin
    wFunc := FO_DELETE;
    fFlags := FOF_FILESONLY or
              FOF_NOCONFIRMATION or
              FOF_NO_CONNECTED_ELEMENTS or
              FOF_NOERRORUI or
              FOF_NO_UI;
    pFrom := PChar(fromDir+'\*.*' + #0);
  end;
  Result := (0 = ShFileOperation(fos));
end;

How do I get it to recursively delete all the files in the path?

MSDN documentation

EDIT

The problem is the FOF_FILESONLY flag After removing it files are recursively deleted

Answer 1

From the MSDN documentation:

FOF_NORECURSION:

Only perform the operation in the local directory. Don't operate recursively into subdirectories, which is the default behavior.

Looks like that's your answer right there.

EDIT: Looks like there's a problem with your flags. You need to or them together, not add them together. Since FOF_NO_UI already includes FOF_NOERRORUI, adding it again can change the value, and you might be accidentally adding some things together that add up to FOF_NORECURSION. It should look like this:

    fFlags := FOF_FILESONLY or
              FOF_NOCONFIRMATION or
              FOF_NO_CONNECTED_ELEMENTS or
              FOF_NOERRORUI or
              FOF_NO_UI;

Answer 2

Do you have to keep the directory also? If not you could just pass

pFrom := PChar(fromDir+#0);

Another option is to build a list of #0-delimited file-paths, and pass that with an extra #0, from msdn:

Although this member is declared as a null-terminated string, it is used as a buffer to hold multiple file names. Each file name must be terminated by a single NULL character. An additional NULL character must be appended to the end of the final name to indicate the end of pFrom.