DBGrid columns visible/not visible
lazarus / 16-Databases

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rkamarowski · 2008-06-03 14:50

I'm trying to reuse a single DBGrid for multiple tables.  I have a
list box, and when an entry is selected all columns are made
invisible, and only the selected table entries are made visible.  It
works fine the first time the entry is clicked.  The second time the
entry is clicked all the fields show up.

Example in the following code:

Chemical is clicked in the list box.  The CHEMICALID field is
invisible and the CHEMICAL field is visible with the title caption
Chemical.  I click on another entry and nothing happens (which is fine
at the moment).  If I click Chemical again, both the CHEMICALID and
CHEMICAL field are visible, and the CHEMICAL title caption is no
longer Chemical, but CHEMICAL.

Code: [Select]procedure TFormMain.ListBoxTablesClick(Sender: TObject);
var
   i: integer;
   index: integer;
begin
  index:=ListBoxTables.ItemIndex;
  if index<0 then exit;

  // make all columns not visible
  for i:=0 to DBGridGeneric.Columns.Count-1 do
    DBGridGeneric.Columns[i].Visible:=False;
  //DBGridGeneric.Clear;
  // chemical table
  if ListBoxTables.Items[index]='Chemical' then
    begin
      ZTableGeneric.TableName:='CHEMICAL';
      ZTableGeneric.SortedFields:='CHEMICAL';
      ZTableGeneric.Active:=True;
      with DBGridGeneric do
        begin
          for i:=0 to Columns.Count-1 do
            if Columns[i].Title.Caption='CHEMICALID' then
              Columns[i].Visible:=False;
            if Columns[i].Title.Caption='CHEMICAL' then
              begin
                Columns[i].Title.Caption:='Chemical';
                Columns[i].Visible:=True;
              end;
           showmessage(booltostr(columns[0].Visible));
        end;
    end; // chemical table
{
  // measure units table
  if ListBoxTables.Items[index]='Measure Units' then
  showmessage('yup');

    begin
      with DBGridGeneric do
        begin
          ZTableGeneric.TableName:='MEASURE UNITS';
          ZTableGeneric.SortedFields:='UNITS';
          for i:=0 to Columns.Count-1 do
            if Columns[i].Title.Caption='UNITS' then
              begin
                Columns[i].Title.Caption:='Unit';
                Columns[i].Visible:=True;
              end;
         end;
     end; // measure units
 }
end;

What am I doing wrong?

bob k.

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OnixJr · 2008-06-03 22:44

Can you upload a sample program?

Actually, I'm using a routine that close dataset, clear columns,
create new columns and open the dataset again...

Here a piece of the code:
Code: [Select]
procedure TfrRelatorios.ViewReport;
  procedure NewColumn(Col: TColumn; FN: String; Cap: TCaption; Wid:
Integer);
  begin
    with Col do
    begin
      FieldName := FN;
      Width := Wid;
      Title.Caption := Cap;
    end;
  end;
var
  I: Byte;
  stSQL: String;
begin
  dmModulo.SQLdsRelatorio.Close;

  case rgTipoRelatorio.ItemIndex of
    0:
      begin
        with dmModulo.SQLdsRelatorio do
        begin
          stSQL := 'SELECT %s FROM produtos;';
          SQL := Format(stSQL, ['produto, SUM(preco), SUM(qtde)']);
          Open;
          {..}
          Close;

          // Start TDBGrid
          SQL := Format(stSQL, ['*']);
          with dbgRelatorio do
          begin
            with Columns do
            begin
              Clear;
              for I := 0 to 4 do
                Columns.Add;
              NewColumn(TColumn(Columns[0]), 'codigo', 'Código', 50);
              NewColumn(TColumn(Columns[1]), 'produto', 'Produto',
450);
              NewColumn(TColumn(Columns[2]), 'preco', 'Preço', 55);
              NewColumn(TColumn(Columns[3]), 'vendas', 'Vendas', 50);
              NewColumn(TColumn(Columns[4]), 'qtde', 'Quantidade',
60);
            end;
          end;
        end;
      end;
    1:
      begin
        stSQL := 'SELECT %s FROM vendas ';
        {...}

        // Start TDBGrid
        dmModulo.SQLdsRelatorio.SQL := Format(stSQL, ['*']);
        with dbgRelatorio do
        begin
          with Columns do
          begin
            Clear;
            for I := 0 to 5 do
              Columns.Add;
            NewColumn(TColumn(Columns[0]), 'codigo', 'Código', 50);
            NewColumn(TColumn(Columns[1]), 'produto', 'Produto', 400);
            NewColumn(TColumn(Columns[2]), 'interno', 'Interno', 50);
            NewColumn(TColumn(Columns[3]), 'preco', 'Preço', 55);
            NewColumn(TColumn(Columns[4]), 'data', 'Data', 75);
            NewColumn(TColumn(Columns[5]), 'hora', 'Hora', 35);
          end;
        end;
      end;
  end;

  dmModulo.SQLdsRelatorio.Open;
end;


Regards,
Júnior

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rkamarowski · 2008-06-04 13:00

Junior,

How do I upload the zip file?

bob k.

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OnixJr · 2008-06-04 15:46

Try http://www.uploading.com/

Regards,
Júnior

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rkamarowski · 2008-06-04 16:06

Junior,

Here's the link:

http://www.uploading.com/files/EMZHVH5Q/Lazarus.zip.html