Tratamiento de errores entorno al API de Windows

[[seoane]]

Bueno, yo crearia una funcion como esta:

Código Delphi [-]
const
  DE_SAMEFILE  = $71;
  DE_MANYSRC1DEST  = $72;
  DE_DIFFDIR  = $73;
  DE_ROOTDIR  = $74;
  DE_OPCANCELLED  = $75;
  DE_DESTSUBTREE  = $76;
  DE_ACCESSDENIEDSRC  = $78;
  DE_PATHTOODEEP  = $79;
  DE_MANYDEST  = $7A;
  DE_INVALIDFILES  = $7C;
  DE_DESTSAMETREE  = $7D;
  DE_FLDDESTISFILE  = $7E;
  DE_FILEDESTISFLD  = $80;
  DE_FILENAMETOOLONG  = $81;
  DE_DEST_IS_CDROM  = $82;
  DE_DEST_IS_DVD  = $83;
  DE_DEST_IS_CDRECORD  = $84;
  DE_FILE_TOO_LARGE  = $85;
  DE_SRC_IS_CDROM  = $86;
  DE_SRC_IS_DVD  = $87;
  DE_SRC_IS_CDRECORD  = $88;
  DE_ERROR_MAX  = $B7;
  DE_UNKHOWN = $402;
  ERRORONDEST  = $10000;

function SHCheck(Value: Integer): Boolean;
var
  Error: EOSError;
begin
  if Value <> 0 then
  begin
    Result:= FALSE;
    case Value of
      DE_SAMEFILE: Error:= EOSError.Create('The source and destination files are the same file.');
      DE_MANYSRC1DEST: Error:= EOSError.Create('Multiple file paths were specified in the source buffer, but only one destination file path.');
      DE_DIFFDIR: Error:= EOSError.Create('Rename operation was specified but the destination path is a different directory. Use the move operation instead.');
      DE_ROOTDIR: Error:= EOSError.Create('The source is a root directory, which cannot be moved or renamed.');
      DE_OPCANCELLED: Error:= EOSError.Create('The operation was cancelled by the user, or silently cancelled if the appropriate flags were supplied to SHFileOperation.');
      DE_DESTSUBTREE: Error:= EOSError.Create('The destination is a subtree of the source.');
      DE_ACCESSDENIEDSRC: Error:= EOSError.Create('Security settings denied access to the source.');
      DE_PATHTOODEEP: Error:= EOSError.Create('The source or destination path exceeded or would exceed MAX_PATH.');
      DE_MANYDEST: Error:= EOSError.Create('The operation involved multiple destination paths, which can fail in the case of a move operation.');
      DE_INVALIDFILES: Error:= EOSError.Create('The path in the source or destination or both was invalid.');
      DE_DESTSAMETREE: Error:= EOSError.Create('The source and destination have the same parent folder.');
      DE_FLDDESTISFILE: Error:= EOSError.Create('The destination path is an existing file.');
      DE_FILEDESTISFLD: Error:= EOSError.Create('The destination path is an existing folder.');
      DE_FILENAMETOOLONG: Error:= EOSError.Create('The name of the file exceeds MAX_PATH.');
      DE_DEST_IS_CDROM: Error:= EOSError.Create('The destination is a read-only CD-ROM, possibly unformatted.');
      DE_DEST_IS_DVD: Error:= EOSError.Create('The destination is a read-only DVD, possibly unformatted.');
      DE_DEST_IS_CDRECORD: Error:= EOSError.Create('The destination is a writable CD-ROM, possibly unformatted.');
      DE_FILE_TOO_LARGE: Error:= EOSError.Create('The file involved in the operation is too large for the destination media or file system.');
      DE_SRC_IS_CDROM: Error:= EOSError.Create('The source is a read-only CD-ROM, possibly unformatted.');
      DE_SRC_IS_DVD: Error:= EOSError.Create('The source is a read-only DVD, possibly unformatted.');
      DE_SRC_IS_CDRECORD: Error:= EOSError.Create('The source is a writable CD-ROM, possibly unformatted.');
      DE_ERROR_MAX: Error:= EOSError.Create('MAX_PATH was exceeded during the operation.');
      DE_UNKHOWN : Error:= EOSError.Create('An unknown error occurred. This is typically due to an invalid path in the source or destination. This error does not occur on Microsoft Windows Vista and later.');
      ERRORONDEST: Error:= EOSError.Create('An unspecified error occurred on the destination.');
      DE_ROOTDIR or ERRORONDEST: Error:= EOSError.Create('Destination is a root directory and cannot be renamed.');
    else
      Error:= EOSError.Create('Error desconocido');
    end;
    Error.ErrorCode:= Value;
    raise Error;
  end else
    Result:= TRUE;
end;

Y modificaría tu función de la siguiente manera:

Código Delphi [-]
function MoverCarpeta(const carpetaOrigen,
  carpetaDestion: string) : boolean;
var
  FileOp: TSHFileOpStruct;
begin
  FillChar(FileOp, SizeOf(FileOp),#0);
  with FileOp do begin
    wFunc := FO_MOVE;
    Wnd := GetActiveWindow();
    pTo := PChar(carpetaOrigen);
    pFrom := PChar(carpetaDestion+#0#0);
    fFlags := FOF_NOCONFIRMATION or FOF_SILENT
     or FOF_ALLOWUNDO or FOF_NOERRORUI;
  end;
  Result:= FALSE;
  if SHCheck(ShFileOperation(FileOp)) then
    Result := not FileOp.fAnyOperationsAborted;
end;

Ahora para dejarlo bonito deberías traducir los mensajes de error