Can't delete folder from a different partition - delphi

Question

I'm having a problem when deleting folders that are on a different partition (E:/) from my software. I can delete files, using the DeleteFile function, but I'm not able to delete a folder using the code below:
function RemoveDirectory(strDir : String) : Boolean;
var
SearchRec : TSearchRec;
strFile : String;
nResult : Integer;
begin
try
Result := false;
nResult := FindFirst(strDir + '*', faAnyFile, SearchRec);
while (nResult = 0) do
begin
if (SearchRec.Name <> '.') and (SearchRec.Name <> '..') then
begin
strFile := strDir + SearchRec.Name;
if FileExists(strFile) then
DeleteFile(strFile)
else if DirectoryExists(strFile) then
RemoveDirectory(strFile);
end;
nResult := FindNext(SearchRec);
end;
Result := RemoveDir(strDir);
finally
FindClose(SearchRec);
end;
end;
With this code I can delete folders that are on the same partition from my software. Somebody knows what's going on? Is it because it's on a different partition?

Answer 1

You are trying to remove directories while you still have open search handles. Since this is a recursive function, if the directory hierarchy is deep, you would have multiple search handles open at a time and that is a lot of system resources being used when the deeper folders are reached.
It is better to collect the immediate subfolders into a temp list, then you can close the current search handle before iterating that list. This way, there is ever only 1 search handle active at a time, and there is no search handle active when each folder is actually being deleted.
Try this:
function RemoveDirectory(strDir : String) : Boolean;
var
SearchRec : TSearchRec;
nResult,i : Integer;
SubFolders: TStringList;
begin
SubFolders := nil;
try
strDir := IncludeTrailingPathDelimiter(strDir);
nResult := FindFirst(strDir + '*', faAnyFile, SearchRec);
if (nResult = 0) then
try
repeat
if (SearchRec.Attr and faDirectory) = 0 then
DeleteFile(strDir + SearchRec.Name)
else
begin
if (SearchRec.Name <> '.') and (SearchRec.Name <> '..') then
begin
if not Assigned(SubFolders) then SubFolders := TStringList.Create;
SubFolders.Add(strDir + SearchRec.Name);
end;
end;
until FindNext(SearchRec) <> 0;
finally
FindClose(SearchRec);
end;
if Assigned(SubFolders) then
begin
for i := 0 to SubFolders.Count-1 do
RemoveDirectory(SubFolders[i]);
end;
finally
SubFolders.Free;
end;
Result := RemoveDir(strDir);
end;
If this still fails, then someone else outside of your app/loop is actually using the directories, and you can use a tool like SysInternals Process Explorer to check that.

Answer 2

DeleteFile() is boolean function and you can receive only information was it successful or not. If you want more details return to the plain old Erase():
var f: file;
begin
AssignFile(f,strFile);
Erase(f);
end;
Here, if Erase() is not completed, an exception will be raised and you can receive more info, especially in the debugging phase.