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Delphi - restore the actual row in a DBGrid

D6 prof.

We used to use DBISAM and DBISAMTable. This handles RecNo, and it works great with changes (Delete, edit, etc.).

Now we have replaced ElevateDB which do not process RecNo, and many times we use Queries, not Tables.

The request must be open to view the changes.

But if we open the request again, we need to rearrange it to the last record. Locate is not enough because the grid shows it on a different line. This is very troubling, because after the change record has moved to another line, it’s hard for you to follow it, and users hate it.

We found this code:

function TBaseDBGrid.GetActRow: integer;
begin
 Result := -1 + Row;
end;


procedure TBasepDBGrid.SetActRow(aRow: integer);
var
 bm : TBookMark;
begin
 if IsDataSourceValid(DataSource) then with DataSource.DataSet do begin
  bm := GetBookmark;
  DisableControls;
  try
   MoveBy(-aRow);
   MoveBy(aRow);
   //GotoBookmark(bm);
  finally
   FreebookMark(bm);
   EnableControls;
  end;
 end;
end;

moveby. , , , .

EDBTable Live/Sensitive Query, MoveBy , - , .

BookMark (. ). , Row...

, : DBGrid?

DBGrid / DataSet?

, , DBGrid , , ...: - (

, , :  

+5
4

"MoveBy" , .

"" . , , "MoveBy". , DataSet.CompareBookmarks. 0 , , "GotoBookmark" .

, , / , , , , , .

edit: , , /. , / , .

type
  TAccessDBGrid = class(TDBGrid);

procedure TForm1.Button1Click(Sender: TObject);
var
  BmSave, Bm: TBookmark;
  GridRow, TotalRow: Integer;
begin
  GridRow := TAccessDBGrid(DBGrid1).Row;
  TotalRow := TAccessDBGrid(DBGrid1).RowCount;
  BmSave := DBGrid1.DataSource.DataSet.GetBookmark;
  try

    // close dataset, open dataset...

    if DBGrid1.DataSource.DataSet.BookmarkValid(BmSave) then
      DBGrid1.DataSource.DataSet.GotoBookmark(BmSave);
    Dec(TotalRow);
    if GridRow < TotalRow div 2 then begin
      DBGrid1.DataSource.DataSet.MoveBy(TotalRow - GridRow);
      DBGrid1.DataSource.DataSet.MoveBy(GridRow - TotalRow);
    end else begin
      if dgTitles in DBGrid1.Options then
        Dec(GridRow);
      DBGrid1.DataSource.DataSet.MoveBy(-GridRow);
      DBGrid1.DataSource.DataSet.MoveBy(GridRow);
    end;
    Bm := DBGrid1.DataSource.DataSet.GetBookmark;
    try
      if (DBGrid1.DataSource.DataSet.BookmarkValid(Bm) and
          DBGrid1.DataSource.DataSet.BookmarkValid(BmSave)) and
          (DBGrid1.DataSource.DataSet.CompareBookmarks(Bm, BmSave) <> 0) then
        DBGrid1.DataSource.DataSet.GotoBookmark(BmSave);
    finally
      DBGrid1.DataSource.DataSet.FreeBookmark(Bm);
    end;
  finally
    DBGrid1.DataSource.DataSet.FreeBookmark(BmSave);
  end;
end;
+8

() , Locate . DisableControls/EnableControls, .

+1

, :

procedure DoRefresh(Dataset: TDataset);
var
  bkm: TBookmark;
begin
  Dataset.UpdateCursorPos;
  bkm := Dataset.GetBookmark;
  Dataset.DisableControls;
  try
    Dataset.Refresh;  //refresh dataset if it open

    if Dataset.BookmarkValid(bkm) then
    begin
      Dataset.GotoBookmark(bkm);
    end;
  finally
    Dataset.EnableControls;
    Dataset.FreeBookmark(bkm);
  end;
end;
0

, Query/Table. , , , , , , , , , , MSSQL Firebird , Order By.

, , TOndrej - , .

0

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