使用SHFileOperation删除文件

今天使用SelectDirectory选择文件夹，用SHFileOperation来删除文件夹，一直都报错，蛋疼了老半天，原来是SelectDirectory之后就将当前目标设为SelectDirectory选择的目录了，所以删除时就会报“文件夹正在使用，不能删除”，最后用在调用SelectDirectory之后，再用SetCurrentDir将当前目录设为“C:\”就Ok了。

procedure TForm1.DeleteDirectoryTree(AHandle: THandle; const ADelDir: string);
var
  SHFileOpStruct: TSHFileOpStruct;
  DelDir: PChar;
  DirLen: Integer;
begin
  DirLen := Length(ADelDir) + 2;
  GetMem(DelDir, DirLen);
  try
    FillChar(DelDir^, DirLen, #0);
    StrCopy(DelDir, PChar(ADelDir));

    with SHFileOpStruct do
    begin
      Wnd     := AHandle;
      wFunc   := FO_DELETE;
      pFrom   := DelDir;
      pTo     := nil;
      fFlags  := FOF_ALLOWUNDO;
      fAnyOperationsAborted := False;
      hNameMappings := nil;
      lpszProgressTitle := nil;

      if SHFileOperation(SHFileOpStruct) <> 0 then
        RaiseLastWin32Error;
    end;
  finally
    FreeMem(DelDir, DirLen);
  end;

end;

function TForm1.GetDirectory: string;
var
  CurDir: string;
begin
  CurDir := 'C:\';

  // if call SelectDirectory, then set current directory is result
  // so if don't set current directory, can not delete the folder
  if not SelectDirectory(Result, [], 0) then
    Result := EmptyStr;

  SetCurrentDir(CurDir);
end;